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Evaluation of long term outcome of auditory training programs in children with auditory processing disorders
International Journal of Pediatric Otorhinolaryngology 79 (2015) 2404–2410
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International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Evaluation of long term outcome of auditory training programs in children with auditory processing disorders Somaia Tawfik a, Dalia Mohamed Hassan a,*, Reham Mesallamy b a b
Audiology Unit, ORL Dept., Faculty of Medicine, Ain Shams University, Abassia Street, Cairo, Egypt Audiology Unit, ORL Dept., El-Mataria Teaching Hospital, El-Mataria Square, Cairo, Egypt
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 August 2015 Received in revised form 1 November 2015 Accepted 3 November 2015 Available online 14 November 2015
Objectives: To evaluate the long term effects of Arabic auditory training ‘AT’ programs in Egyptian schoolaged children with auditory processing disorders ‘APD’. Methods: Thirty children with APD who received the proper regular AT for minimum duration of 2 months were included. They were subjected to functional measures ‘questionnaire for APD’ and psychophysical test battery. It comprised dichotic digits, pitch pattern sequence ‘PPS’, gap in noise detection ‘GIN’ and the memory tests. New bench mark battery was applied in the form of the duration pattern, the dichotic rhyme and the informal memory tests. The results of different tests were compared across the evaluation sessions ‘pre-training, immediate post training, and the late outcome’. Results: The children were evaluated after mean duration 24.5 months, ranged 7–42 months from the end of AT. No deterioration in the scores of Arabic questionnaire or the psychophysical tests was observed compared to the immediate post training evaluation. The bench mark tests scores matched the age based norms. A statistical significant correlation existed between PPS, GIN tests and the functional measures. Conclusion: The outcome of the AT program showed long term consistency. The temporal processing tests (PPS, GIN) were sensitive tools in monitoring the progress of training. The new bench mark test battery used was effective as the diagnostic test battery in assessing the long term effects of AT program. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: APD Auditory training Long term outcome
1. Introduction Auditory processing disorder (APD) is a complex problem affecting about 7% of school aged children [1]. It refers to difficulties in the perceptual processing of auditory information in the central nervous system as demonstrated by poor performance in one or more of the auditory skills [2]. The auditory skills comprises sound localization and lateralization; auditory discrimination; auditory pattern recognition; temporal aspects of audition; auditory performance in competing acoustic signals (including dichotic listening); and auditory performance with degraded acoustic signals [3]. Although APD may coexist with other disorders (e.g., ADHD, language impairment, and learning disabilities), it is not the result of these other disorders. These disorders are not due to a deficit in the central
* Corresponding author at: Audiology Unit, ENT Dept., Faculty of Medicine, Ain Shams University, Abbassia Street, Cairo, Egypt. E-mail address: [email protected] (D. Mohamed Hassan). http://dx.doi.org/10.1016/j.ijporl.2015.11.001 0165-5876/ß 2015 Elsevier Ireland Ltd. All rights reserved.
auditory nervous system (CANS) and the listening difficulties exhibited by these children occur when co-morbidity deficit in the CANS can be demonstrated [2]. Management of APD may be viewed as a tripod with three legs that include environmental modification, compensatory strategies and direct skill remediation techniques (auditory training). Without all the three legs, the tripod cannot stand [3,4]. Auditory training ‘AT’ programs relied on the fact that the auditory system can undergo changes in response to intensive auditory training. These changes are maximal within a certain critical period of time [5]. They are classified into formal and informal programs. Coupling formal and informal auditory training should maximize treatment efficiency [6,7]. The development and implementation of AT programs in Arabic language dated since 2000. Several programs, both formal and informal, targeting nearly all the affected central processing abilities were standardized and evaluated in the Audiology Unit, Ain Shams University. Satisfactory outcome and consistent results were reported when applied on Arabic-speaking children with APD [8–11].
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The process of capturing clinical outcomes of APD has been labor intensive work but has lacked integration. Many researchers reported significant improvement after AT in children with APD [12]. The recent technical report issued by experts in the field of APD and published by ASHA pointed that additional data are needed to demonstrate the effectiveness and efficacy of these approaches [2] Preliminary findings indicated that late occurring effects of the remediation programs existed and showed improvement of skills in individuals with APD when assessed after 8 weeks of remediation [13]. Most of studies evaluating the outcome of AT programs considered a maximal period from 3 to 6 months after finishing training and not for longer periods. Tallal [14] showed consistent improvement for long term evaluation at 3 and 6 months. However, Tallal study was only on limited number of children using Fast forwards FFW. The short term consistency for the Arabic AT programs ‘up to 6 months’ was previously reported [8,9,11]. Rogowsky et al. [15] advised follow-up testing over time to determine the longer-term effects of computer-based interventions for improving reading and writing outcomes in struggling students. Future results would fill the gaps in literature and provide more definitive conclusions and recommendations about the consistency of AT programs which make real differences in the lives of children with APD and their families over longer periods [16]. Meanwhile the long term outcome of AT programs on the Egyptian children with APD has not been investigated yet. Accordingly, this study was designed to evaluate the long term effects of Arabic auditory training programs in a group of Egyptian school-aged children with APD. Those children were diagnosed with APD and received the proper intensive auditory training at time of diagnosis. Variables affecting such outcome were also highlighted. 2. Materials and methods 2.1. Subjects The present study was conducted into two steps. 2.1.1. Retrospective work up This step was done to collect data about children that could participate in the study. All files of children in the clinic for APD – Audiology Unit, El-Demerdash Hospital, Ain Shams University, Cairo – Egypt were reviewed. Four hundred children were examined during the period from 2006 to 2013. Diagnosis of APD was settled in 115 (29%) children and 40 children (35%) completed the scheduled AT program. Criteria for inclusion in the present study were settled diagnosis of APD, proper regular training at time of diagnosis. The minimum duration required for inclusion in this study was 2 months of regular therapy, twice weekly and for 30 min each. All children should have normal peripheral hearing sensitivity as shown by pure tone audiometry thresholds <15 dB HL for frequencies 500– 4000 Hz, excellent speech discrimination scores and normal middle ears functions. They had at least average psychointellectual abilities as measured by the Arabic Hiskey Nebraska test of learning aptitude with no associated neurological disorders. A group of 30 school-aged children (26 males ‘87%’ and 4 females ‘13%’) fitted the above mentioned criteria. Their mean age was 11 1/2 (2.5) years, ranged from 7 to 16 1/2 years. All children had mean intelligence quotient 87 7 and range 80–94. Twenty-six children (87%) were right handed and four children (13%) were left handed. They were enrolled in ordinary schools. Their school grades matched their chronological ages except two children. Twenty-two children (72%) were in primary grades, five (16%) in preparatory grades and the remaining three (1%) in secondary grades.
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At time of diagnosis, the majority of study group children (n = 17, 57%) had more than two affected auditory abilities; eight children had two affected abilities (26%), while one affected ability was met in five (17%). The auditory temporal processing ability was the commonest ability affected (n = 21) followed by memory disorders (n = 19) and dichotic listening disorders (n = 17). The selective auditory attention problem was seen in three subjects. Other higher cognitive communicative ability deficit in the form of phonemic awareness problem was found in 11 subjects and auditory attention problem in 1 subject (Fig. 1). All children started remediation for APD before the age of 12 years with a mean age 8 (1.8) years. Twenty-two (73%) children were trained received formal training using the Arabic computer based Arabic auditory training program ‘CBAT’ [9]. The remaining eight (27%) children received combined formal and informal training. The mean duration of training was 5.45 (3.97) months and range from 2 to 18 months. Only two children continued to receive training for 18 months as they had more than two affected central auditory abilities that necessitated long course of therapy. The CBAT program used for training of study group children was specifically implemented for treatment of Arabic-speaking children with APD and associated language learning problems [9]. It was designed according to the scientific principle of remediation to train several auditory processing abilities in a highly interesting and attractive theme [3,4,7]. The developed program was classified according to the trained auditory abilities into: (1) Bottom-up processed abilities (central auditory processing abilities) which include auditory temporal processing, selective auditory attention, auditory dichotic listening, inter-hemispheric transfer of information and auditory closure [2]. (2) Top-down processed abilities (cognitive-communicative abilities) which include auditory vigilance, auditory memory, phonological awareness and language comprehension. It consisted of three phases classified according to the used material: phase I with non-verbal material, phase II with simple verbal Arabic material, phase III with complex verbal Arabic material. Acoustic modifications were done whenever needed according to the ability trained. As an example, amplitude and frequency modulated tones with variable inter stimulus interval, prolongation of voice onset time for consonants were applied in games for auditory temporal processing disorder. Moreover, in each game the multimedia software extends to improve the visual attention and sustained visual/auditory attention together with the trained central auditory ability. This is accomplished through developing the ability to focus attention, ignore distractions, and respond quickly when stimulus changes. The program strengthens visual processing skills and sensory-motor integration through auditory to visual to motor co-ordination and fine motor skills.
Fig. 1. Distribution of study group children according to the affected auditory ability.
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2.1.2. Prospective work up It was carried out to assess the long term outcome of APD remediation and included functional measures and psychophysical APD test battery. 2.1.2.1. Functional measures. – APD questionnaire for children ‘Arabic version’ [17]. It included divided sections to assess the listening, language, memory and learning aspects. The parents answered the questions in yes or no choice. The total percent score was calculated. – The school performance of the child. It was used as guide for the child learning situation after receiving the proper APD training. It was estimated at the time of outcome evaluation of the present study and was based on the child’s certificate whether excellent (85–100%), good (70–<85), or average (50–<70). 2.1.2.2. Psychophysical CAPD test battery. Using the Arabic test battery for children [17]. This was carried out in sound treated room IAC model 1602 using two channel audiometer GrasonStadler. Inc. (GSI) Model 61 calibrated according to ANSI (1969) with a sound field testing facility. The recorded APD test materials were delivered through Cassette tape recorder with CD player via headphone or loud speaker according to the nature of the test. All tests are delivered at 50 dB SL (re: speech reception threshold). Two test batteries were applied for the study group children. The first test battery. It included some of the tests used during the APD diagnosis process and in immediate post remediation evaluation. The tests used were: dichotic digits test ‘DD’ in Arabic language [18]. Being a test for binaural integration ability, two versions were conducted and the scores were calculated as percent correct scores for each ear alone. The pitch pattern sequence test ‘PPS’ [19] with its discrimination ‘PD’ and sequencing ‘PPS’ subtests was applied to test the auditory temporal ordering and sequencing ability. The response mode was either verbal or humming and the scoring was calculated as percent correct. The gap in noise detection test ‘GIN’ [13] targeted the temporal resolution ability. The number of correct responses out of the total gaps number for each ear was estimated. Memory sub-tests in Arabic language comprised three memory subtests: recognition memory, memory for content, and memory for sequence [20]. The scoring for recognition memory was the highest score out of 11 estimated, and the highest number of words the child could repeat was scored for memory for content and memory for sequence subtests. The second battery. It was considered as bench mark tests for the evaluation of the outcome. This battery was used in order to avoid the learning effect from using tests already applied in diagnosis and in immediate post remediation evaluation. It included: duration pattern test ‘DPT’ [21] as a test for temporal ordering, the dichotic rhyme test in Arabic language ‘DRT’ [22] for the binaural integration ability. The scoring for these tests was a percent correct scores for each ear alone. The informal memory test in Arabic language [11] was also included to test the sequential memory. The materials used for the informal memory tests consisted of four lists of Arabic monosyllabic words items. The first list started with two words in sequence then the number of words increased up to five words in sequence in list ‘40 . The children had to memorize the target words in the correct sequence. The highest number of words the child could repeat in a correct sequence was calculated. An informed consent was taken from the parents of children prior to participation in the present study. The study protocol was approved by the Ethics Committee of faculty of medicine, AinShams University.
2.2. Statistical analysis Statistical analyses were performed using (SPSS) 16.0. Data were expressed as mean SD for quantitative parametric measures. The paired t-test was applied to compare between two dependent groups for parametric data. Repeated measures analysis of variance ‘ANOVA’ studied the within subjects factors across the evaluation time. The effect sizes were estimated and interpreted according to Cohen [23]. The Ranked Spearman correlation test studied the possible association between each two variables among each group for non-parametric data. The probability of error at 0.05 was considered significant. 3. Results 3.1. Immediate post remediation The immediate post remediation functional and psychophysical tests results for the study group showed marked improvement in almost all tests. Functional measures. The scores of the Arabic version of APD questionnaire significantly improved from 53 (14) % preremediation to 65 (11) % following immediate remediation (p < 0.01). Ten children (34%) improved in listening aspects, five (17%) in learning and listening, four (13%) in learning, another four in memory items and three children (10%) in language items. Improvement in all items was reported by four subjects (13%) (Fig. 2). Based on the school certificate, the mean school scores were at least good to excellent scores (n = 24, 80%) denoting acceptable scholastic performance following auditory training. Average school performance was reported in six children (20%). Some children still had difficulties in mathematical calculation (n = 3, 10%), difficulty in studying languages including Arabic, foreign languages (n = 9, 30%) and in social studies (n = 3, 10%). The parents of six children (20%) reported bad hand writing. Although better than before training, the parents of 12 children (40%) complained of poor memory. Looking to the psychophysical central test battery scores, statistical significant difference between pre and immediate post remediation evaluations in all the tests (p < 0.05). The scores approached the normal age matched 95 confidence limits (Table 1). The scores of DD tests versions improved in both ears following remediation and age matched normal values were obtained in DD version I. Meanwhile, a statistical significant higher scores in the right ear compared to left ear were noticed in DD tests. This reflected the apparent right ear advantage (REA) (Fig. 3). The PPS as a test of temporal ordering and sequencing together with temporal sequencing showed marked improvement in postremediation results although still below normative data. Similarly,
Fig. 2. Distribution of study group subjects according to the improved items in the Arabic CAPD questionnaire.
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Table 1 Mean (X), standard deviation (SD), paired t-test and p value of pre and immediate post-remediation the Arabic psychophysical tests in the study group. The age based normal 95 confidence limit ‘CL’ is displayed. Test
Pre remediation X (SD)
Post remediation X (SD)
t
p Value
95 CL [reference]
DD I-right ear ‘%’ DD I-left ear ‘%’ DD II-right ear ‘%’ DD II-left ear ‘%’ PPS test ‘%’ GIN test ‘m s’ Recognition memory ‘n’ Memory for content ‘n’ Memory for sequence ‘n’
90 (11) 81.2 (20) 79 (16) 63 (22) 39 (22) 13 (4) 7 (3) 3.5 (1) 3.3 (1)
95.3 (10) 90.6 (17) 85 (10) 4.62 64 (19) 8 (3) 10 (1.5) 4.2 (1) 4 (1)
2.69 2.74 2.28 75 (17) 3.78 8.22 7.53 6.24 6.43
0.01* 0.01* 0.03* 0.00* 0.001* 0.000* 0.000* 0.000* 0.000*
91.5–97% [18] 86.8–91.8% [18] 89–94% [18] 81.8–88% [18] 66.1–83.5% [17] 4.4–5.7 [23] 10.4 (0.4) [20] 5.5 (0.5) [20] 5 (0.5) [20]
* Statistically significant p < 0.05, the shaded cells reflected the test score within the normal 95 CL.
Table 2 Repeated measure analysis of variance and effect size across the evaluation sessions in the different tests in the study group. Test
Pre X (SD)
Immediate X (SD)
Long term outcome X (SD)
F value
p Value
Effect size
Questionnaire ‘%’ DD I-right ear ‘%’ DD I-left ear ‘%’ DD II-right ear ‘%’ DD II-left ear ‘%’ PPS test ‘%’ GIN test ‘m s’ Recognition memory ‘n’ Memory for content ‘n’ Memory for sequence ‘n’
53 (14) 90 ( 11) 81.2 (20) 79 (16) 63 (22) 39 (22) 13 (4) 7 (3) 3.5 (1) 3.2 (1)
65 (11)) 95.3 (10) 90.6 (17) 85 (10) 75 (17) 64 (19) 8 (3) 10 (1.5) 4.1 (1) 3.9(1)
77 (12) 97.2 (6) 95.7 (9.3) 88 (8.2) 79 (15.3) 69 (17.2) 7.6 (3) 10.5 (1.4) 4.7 (0.8) 4.3 (0.9)
30.1 7.1 7.9 9.7 11.1 37.5 33.5 27.5 32.2 29.1
0.000* 0.003* 0.002* 0.002* 0.000* 0.000* 0.000* 0.000* 0.000* 0.000*
0.68 0.33 0.36 0.41 0.44 0.72 0.71 0.66 0.69 0.67
Pre, pre-remediation; immediate, immediate post remediation. * Statistical significant p < 0.05; effect sizes were classified as small (0.2), medium (0.5), and large (0.8) [25].
the timing in GIN test improved and approached the normative data of their age matched norms in Arabic speaking children [24]. Fig. 3: the DD II test showing improvement in the test scores across the evaluation sessions. The difference between the right and left ear test decreased along the three sessions but with persistent statistical significant REA. 3.2. Long term evaluation outcome The study group children were evaluated for the long term effects of AT after mean duration 24.5 months 17.5 SD with a range 7–42 months from the end of APD training. The results showed no deterioration in the scores of Arabic questionnaire or the psychophysical tests compared to the immediate post training evaluation. The progression of therapy across the three evaluation sessions (pre-training, immediate post training and long term evaluation) was highlighted by repeated measure analysis of variance ‘ANOVA’ for the different tests (Table 2). Repeated measure ANOVA showed that there is significant change in the test scores across the different evaluations reflecting the significant time effect (p < 0.001). The calculated effect sizes were at least medium to large in the different tests. Follow up comparisons indicated that the pairwise difference in the scores of questionnaire, DD II ‘right ear’, PPS test, and memory for content and sequence tests showed statistical significant improvement in late outcome evaluation (Table 3). The significant increase in the scores over time reflected the consistency of the training used. In nearly all tests, marked improvement in immediate post training evaluation scores was obvious. Then the test scores tend to plateau or show mild rise along the long term evaluation reflecting the effectiveness of the training plan (Figs. 3–5). Figs. 3–5. The scores of the questionnaires, PPS, GIN and DD II test scores across the three evaluation sessions in the study group.
To exclude the effect of learning from using the same test battery for diagnosis and short term follow up, a bench mark test battery was applied. It included Arabic DRT, DPT, and informal memory test. The bench mark tests results were displayed in Table 4. The test scores in the three tests, respectively matched the age based test norms as reported by Weheiba et al. [18], Abdel Rahman et al. [26], and Tawfik et al. [11]. The effect of the different variables on the outcome of APD remediation was assessed using the ranked spearman correlation test. Neither the age nor age of starting remediation or duration of training was statistically correlated with the subjective or objective outcome tests (p > 0.5) in the present study. This pointed to the direct effect of AT programs and not the maturation or learning effect of the tests used. The consistency of the remediation program regardless the time elapsed since end of
Fig. 3. Dichotic digits II test scores.
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100
Table 3 Pair wise comparisons for the psychophysical tests and questionnaire across the evaluation sessions.
Questionnaire
DD I-right ear
DD I-left ear
DD II-right ear
DD II-left ear
PPS test
GIN test
Recognition memory
Memory for content
Memory for sequence
Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate
Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late
Mean difference
p Value
12.4 24.3 12 5.4 7.2 1.7 9.4 14.5 5.1 5.6 9 3.4 12 16 4 24.3 30 5 4.7 4.9 0.4 3 3.4 0.5 0.6 1.2 0.5 0.7 1.1 0.4
0.001* 0.000* 0.001* 0.04* 0.002* 0.89 0.03* 0.002* 0.25 0.03* 0.001* 0.008* 0.000* 0.000* 0.27 0.000* 0.000* 0.04* 0.000* 0.000* 0.2 0.000* 0.000* 0.7 0.000* 0.000* 0.001* 0.000* 0.000* 0.004*
Pre, pre-remediation; immediate, immediate post remediation; late, late outcome evaluation. * Statistical significant p < 0.05, the shaded cells reflected the tests with persistent significance improvement in scores at late outcome evaluation.
% correct scores
Evaluation time
Test
90 80 70 60 50 40 30 20 10 0 Immediate post remediation
Pre remediation
Long term evaluation
Evaluation sessions Fig. 5. PPS test scores.
Table 4 Mean (X), standard deviation (SD), range of the bench mark test battery in the study group. The age based normal 95 confidence limit ‘CL’ is displayed. Test
X
SD
95 CL [reference]
DPT ‘%’ DRT Rt ear ‘%’ DRT Lt ear ‘%’ Informal memory ‘n’
66.5 57.3 39.4 4.5
16.3 8.02 9.6 0.6
65–100% [26] 33–80% [18] 28–60% [18] 4–5 [11]
Table 5 Ranked Spearman correlation test for the function measures and the PPS, GIN tests in the study group children. Test
PPS ‘%’ GIN test ‘m s’
CAPD questionnaire
School scores
r
p
r
p
0.497 0.47
0.012* 0.022*
O.454 0.415
0.005* 0.009*
* Statistically significant p < 0.05.
100 90
% correct scores
80 70 60 50 40 30 20 10 0 Pre remediation
Immediate post remediation
Long term evaluation
Evaluation sessions
Fig. 4. CAPD questionnaire scores.
training sessions was powered by the absence of statistical correlations between the treatment outcome results (subjective or objective) and time passed till the present study. A statistical significant correlation existed between PPS, GIN tests, the CAPD questionnaire, and the school scores (p < 0.05) (Table 5). 4. Discussion In agreement with ASHA [2] and the AAA [12] guidelines in managing APD, the study group children had the proper age, language, and mentality to understand the task given for diagnosis and remediation. It was found that 25 children (83%) had more
than one affected auditory ability. The same was reported by Bellis and Ferre [27] and Cestnick and Jerger [28] who stated that APD is a heterogenous complex problem that commonly affects a group of central auditory abilities rather than affecting discrete ability. All children started AT before the age of 12 years with a mean 8 (1.8) years. Musiek and Gollegly [29] reported that the brain plasticity is maximal in young age. The variability in the duration of training in the current study could be explained by the presence of more than two affected abilities that can hinder the efficacy of therapy, making the need for longer durations of training to be considered [3,30]. Immediately following remediation, significant improvement was evident in the psychophysical APD tests as well as subjective measures. Similar results were reported by previous researches [8–11,30,31]. Although training was differing in materials used, language (English versus Arabic) and session schedules, outcome of these programs were promising. It is well known that Arabic, the official language in many countries, has very different grammar from English. Comparing the Arabic language with other languages it can be seen that most of the Arabic consonants have different frequency range than those of other languages while the differences in vowels are not significant [32]. Arabic has 28 consonants (English 24) and 8 vowels/ diphthongs (English 22) with the short vowels are unimportant in Arabic. Kamal et al. [33] found APD in 3.3% of children among the Egyptian population and in 32% among school underachievers. Chermak and Musiek [34] estimated that APD occurs in 2–3% of
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children, with a 2:1 ratio between boys and girls. The prevalence of APD in the general population has not been firmly established with rough estimates of about 5% in school aged children [35]. Notably in the present work, the psychophysical test scores approached the age norms 95 confidence limits but not the ceiling level. The right ear advantage persisted across the different sessions but with decreased differences in the late outcome evaluation reflecting the state of maturation of the corpus callosum (CC). The CC is responsible for inter hemispheric transfer of information and it continues to mature till age of 12 years [30,36]. Moreover, the REA observed in the current study reflected left hemispheric dominance for language and is typically present regardless of handedness. As emphasized by Keith and Anderson [37], the dichotic listening tests are among the most powerful AP tests for the assessment of hemispheric transfer of information, development and maturation of the central auditory nervous system. Obviously, the functional impact of APD on the child real life situations was apparent in the results of questionnaire for APD. The improvement in the questionnaire scores after remediation made it an easy outcome measure for the progress of the training. Moreover, the improvement was marked in all aspects in particular listening followed by learning tasks. Another functional measure in outcome assessment was the performance of children at school. All children were enrolled in school in grades matching their chronological age with at least good scores. Tallal [14] and Baran [38] reported better academic achievement following improvements in central auditory abilities as a direct result of AT. Although the links between them are complex, APD has a potential impact on both language learning and language use and in turn on academic achievements. On comparing the immediate post-remediation and late outcome results, better or nearly same scores for Arabic APD questionnaire and the psychophysical tests were obtained. The improvement in scores reached statistical significant levels for the scores of questionnaire, PPS test, DD II right ear, memory for content and sequence tests. This might be attributed to maturation of auditory pathway together with the effect of neuroplasticity. With repeated stimulations (training) the neural responses become stronger. The responses of the brain fibers to the stimuli used over time increases as a result of the long term potentiation (LP). This LP can be considered a form of plasticity and may be the physiologic mechanism underlying a variety of plastic processes in the nervous system, and being responsible for saving its experienced changes over long periods of time [39]. Chermak and Museik [34] reported that plasticity enables the central nervous system to accommodate and offers speech pathologists and audiologists the opportunity to improve auditory processing. Merzenich et al. [40] and Sharma et al. [41] highlighted that neuroplasticity is induced through experience and stimulation (AT) which in turn leads to reorganization (remapping) of the auditory cortex, improved synaptic efficiency, increased neural density and associated cognitive and behavioral change. The late outcome evaluation for Arabic AT programs, highlighted in the current study, proved the long term consistency of these programs in remediation Arabic speaking children with APD. Tallal and Gaab [42] reported that the outcome of AT programs is lifelong consistent. The evaluation test results of the study group children were not affected by the duration elapsed since last training received. This highlighted the consistency of the training outcome regardless the time elapsed since end of training sessions. Nevertheless, the results of the bench mark test battery pointed to the consistency of the training and excluded any learning effect from repeated evaluation. Miller et al. [43] recommended the use of test battery other than that used for diagnosis to be sure that the results obtained are direct effects of AT, and not due to habituation to the tests used. Accordingly, it is advisable to use the bench mark
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test battery in both short term and long term evaluation of AT programs. This short battery proved its efficacy and can put an end for the debate about the learning effect. It should be applied taking in consideration the age matched norms to the tests used. An important psychophysical measure in monitoring the outcome of AT was the role of temporal processing abilities. This was highlighted by the correlation between subjective measures and PPS, GIN tests. It ensured the role of this ability in detecting the progress of training. Musiek et al. [13] highlighted that GIN test and PPS test are of the few measures that are very sensitive to the therapeutic changes in the central auditory nervous system. Hence, Tallal and Gaab [42] proved that computer-based AT in school aged children improved the rate of acoustic processing and sharpen phoneme perception and phonemic awareness, all critical for reading. 5. Conclusions The outcome of the auditory training programs used for Arabicspeaking children with APD showed long term consistent improvement for periods more than 6 months up to 4 years. The Arabic questionnaire for APD and the school performance proved to be effective subjective measures for long term follow up. The temporal processing tests ‘PPS and GIN’ were sensitive tools in monitoring the progress of training. The new bench mark test battery used was as effective as the diagnostic test battery in assessing the long term effects of AT programs. The authors recommended the use of the bench mark test battery in monitoring the progress of treatment in combination with the auditory evoked potentials. Serial monitoring for the efficacy of training until stabilization of results and/or reaching the age-based normative data is mandatory. Conflicts of interest The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. Acknowledgement The contribution of children and cooperation of parents in this study was highly appreciated. References [1] D. Bamiou, N. Campbell, T. Sirimanna, Management of auditory processing disorders, Hear. Balance Commun. 4 (1) (2006) 46–56. [2] American Speech-Language-Hearing Association, (Central) Auditory Processing Disorders, Working Group on Auditory Processing Disorders, 2005 (Technical Report). Retrieved from: http://www.asha.org/docs/html/TR2005-00043.html. [3] T.J. Bellis, Assessment and Management of Central Auditory Processing Disorders in the Educational Setting: From Science to Practice, second ed., Singular, San Diego, CA, 2003. [4] G.D. Chermak, F.E. Musiek, Auditory training: principles and approaches for remediating and managing CAPD, Semin. Hear. 23 (4) (2005) 297–308. [5] B. Linkenhoker, E. Knudsen, Incremental training increases the plasticity of the auditory space map in adult bran owls, Nature 419 (2002) 293–296. [6] P. Tallal, L.S. Hirsch, T. Realpe-Bonilla, S. Miller, L.M. Brzustowicz, C. Bartlett, et al., Familial aggregation in specific language impairment, JSLHR 44 (2001) 1172–1182. [7] P. Tallal, in: G.D. Chermak, F.E. Musiek (Eds.), Foreward for: Handbook of (Central) Auditory Processing Disorder – Volume II: Comprehensive Intervention, Plural Publishing, 2006. [8] S. Tawfik, N. Hazzaa, A. Shalaby, M. Thabet, Development of an Arabic battery for remediation of selective auditory attention disorder in children, Scand. Audiol. Suppl. 52 (2001) 211–216. [9] S. Tawfik, A. Shalaby, W. El Kholi, D. Mohamed Hassan, M. Thabet, S. El Sady, et al., Development of an Arabic computer-based remediation program for children with central auditory processing disorders, in: Presented in ‘‘28th International Congress of Audiology, Innsbruck, Austria, 2006. [10] S. Tawfik, W. El Kholi, I. El Danasoury, A. Shalaby, M. Thabet, Computer-based remediation program for auditory temporal processing disorders, Sci. J. Al-Azhar Med. Fac. (Girls) 28 (2) (2007).
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[11] S. Tawfik, I. El-Danasoury, A. Shalaby, M. Ramadan, Development of an Arabic remediation program for central auditory processing disorder in children, in: International Association of Logopedics and Phoniatrics: Proceedings CAPD Composium, Cairo, Egypt, 2009, Available from: http://ialp.info/Proceedings-CAPDComposium-Cairo-2009-pg16343.html. [12] AAA, American Academy of Audiology Clinical Practice Guidelines: Diagnosis, Treatment and Management of Children and Adults with Central Auditory Processing Disorder, 2010 Available from: http://www.audiology.org. resources/documentlibrary/Documents/CAPDGuidelines. [13] F.E. Musiek, J.B. Shinn, R. Jirsa, D.E. Bamiou, J.A. Baran, E. Zaida, GIN (Gaps-InNoise) test performance in subjects with confirmed central auditory nervous system involvement, Ear Hear. 26 (6) (2005) 608–618. [14] P. Tallal, Neurobiological and neuropsychological studies of language development and disorders, Adapt. Brain II (1999) 23–35. [15] B.A. Rogowsky, P. Papamichalis, L. Villa, S. Heim, P. Tallal, Neuroplasticity-based cognitive and linguistic skills training improves reading and writing skills in college students, Front Psychol. 4 (2013) 137. [16] British Society of Audiology, Practice Guidance: An Overview of Current Management of Auditory Processing Disorder (APD), 2011 Available from: http://thebsa. org.uk. [17] S. Tawfik, A. Shalaby, Development and standardization of Arabic central test battery for children, in: Proceedings of XXIII World Congress of the International Association of Logopedics and Phoniatrics, 1995, pp. 416–419. [18] H. Weiheba, S. Tawfik, A. Abdel V, Standardization of Two Binaural Dichotic Digits and Dichotic Rhyme Test on Normal Children, 2008 Master thesis, Audiology unit, ORL Dept., Ain Shams University. Available from: http: URL: library.shams.edu.eg. [19] M.L. Pinheiro, P.H. Ptacek, Reversals in the perception of noise and tone patterns, J. Acoust. Soc. Am. 49 (1971) 1778–1782. [20] S. Tawfik, I. El-Danasoury, A. Abdel-Maksoud, H. Abo-Moussa, Auditory attention and memory tests for children: development, standardization and application, Eur. J. Ophthalmol. 19 (2) (2002) 31–34. [21] F.E. Musiek, J.S. Baran, M.L. Pinheiro, Duration pattern recognition in normal subjects and patients with cerebral and cochlear lesions, Audiology 29 (1990) 304–313. [22] L. Khalil, S. Soliman, I. El-Danasoury, Development and Standardization of Arabic Dichotic Rhyme Test, 1997 Master thesis, Audiology unit, ORL Dept., Ain Shams University. Available from: http: URL: library.shams.edu.eg. [23] J. Cohen, Statistical Power Analysis for the Behavioral Sciences, Erlbaum, Hillsdale, NJ, 1988. [24] S. Tawfik, W. El-Kholi, S. Mekki, N. Gad, Gaps-In-Noise Test Versus Auditory Fusion Test in Diagnosis of Auditory Temporal Processing Disorders, 2009 Master thesis, Audiology unit, ORL Dept., Ain Shams University. Available from: http: URL: library.shams.edu.eg. [25] C. Carson, The Effective Use of Effect Size Indices in Institutional Research, 2015 http://www.keene.edu/ir/effect_size.pdf (accessed 16.04.12). [26] A. Abdel Rahman, S. Tawfik, I. El-Danasoury, W. El-Kholi, Assessment of Temporal Processing in Geriatric Population, 2000 Master thesis, Audiology unit, ORL Dept., Ain Shams University. Available from: http: URL: library.shams.edu.eg.
[27] T.J. Bellis, J.M. Ferre, Multidimensional approach to the differential diagnosis of central auditory processing disorders in children, J. Am. Acad. Audiol. 10 (6) (1999) 319–328. [28] L. Cestnick, J. Jerger, Auditory temporal processing and lexical/nonlexical reading in developmental dyslexics, J. Am. Acad. Audiol. 11 (2000) 501–513. [29] F.E. Musiek, K. Gollegly, Maturational considerations in the neuroauditory evaluation of children, in: F. Bess (Ed.), Hearing Impairment in Children, York Press, Parkton, MD, 1988, pp. 231–252. [30] P. Tallal, S.L. Miller, G. Bedi, G. Byma, X. Wang, S.S. Nagarajan, et al., Language comprehension in language-learning impaired children improved with acoustically modified speech, Science 271 (5245) (1996) 81–84. [31] M. Sharma, S.C. Purdy, A.S. Kelly, A randomized control trial of interventions in school-aged children with auditory processing disorders, Int. J. Audiol. 51 (7) (2012) 506–518. [32] K. Miyawaki, W. Strange, R. Verbrugge, M. Liberman, I. Mossallam, S. Soliman, et al., Optimal frequencies of Arabic (Egyptian) sounds, Ain Shams Med. J. 29 (1978) 261–265. [33] N. Kamal, N. Hazzaa, A. Shalaby, W. ElKoli, H. Zytoun, Central auditory processing disorders (CAPD): a potential cause for scholastic underachievement, Eur. J. Ophthalmol. 21 (2) (2004), 209-120. [34] G.D. Chermak, F.E. Musiek, Central Auditory Processing Disorders: New Perspectives, Singular Publishing Group, San Diego, CA, 1997. [35] American Speech–Language–Hearing Association, Doing CAPD Therapy from the Palm of Your Hand, 2012 Retrieved from: http://www.asha.org. [36] F.E. Musiek, G.D. Chermak, J. Weining, Auditory training, in: G.D. Chermak, F.E. Musiek (Eds.), Handbook of (Central) Auditory Processing Disorder, Comprehensive Intervention, vol. II, Plural Publishing, Inc., San Diego, 2007. [37] R.W. Keith, J. Anderson, Dichotic listening tests, in: F.E. Musiek, G.D. Chermak (Eds.), Handbook of (Central) Auditory Processing Disorder, vol. 1, Plural Publishing, San Diego, 2007 (Chapter 9). [38] J. Baran, Managing (central) auditory processing disorders in adolescents and adults, in: G.D. Chermak, F.E. Musiek (Eds.), Handbook of (Central) Auditory Processing Disorder, Comprehensive Intervention, vol. II, Plural Publishing, Inc., San Diego, 2007. [39] E.M. Schuman, D.V. Madison, A requirement for the intercellular messenger nitric oxide in long-term potentiation, Science 254 (1991) 1503–1506. [40] M. Merzenich, W. Jenkins, P. Johnston, C.E. Schreiner, S.L. Miller, P. Tallal, Temporal processing deficits of language-learning impaired children ameliorated by training, Science 271 (5245) (1996) 77–81. [41] A. Sharma, M.F. Dorman, A.J. Spahr, A sensitive period for the development of the central auditory system in children with cochlear implants: implications for age of implantation, Ear Hear. 23 (2002) 532–539. [42] P. Tallal, P.N. Gaab, Dynamic auditory processing, musical experience, and language development, Trends Neurosci. 29 (2006) 382–390. [43] C. Miller, E. Uhring, J. Brown, E. Kowalski, B. Roberts, B. Schaefer, Case studies of auditory training for children with auditory processing difficulties: a preliminary analysis, Contemp. Issue Commun. Sci. Disord. 32 (2005) 93–107.
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Evaluation of long term outcome of auditory training programs in children with auditory processing disorders Somaia Tawfik a, Dalia Mohamed Hassan a,*, Reham Mesallamy b a b
Audiology Unit, ORL Dept., Faculty of Medicine, Ain Shams University, Abassia Street, Cairo, Egypt Audiology Unit, ORL Dept., El-Mataria Teaching Hospital, El-Mataria Square, Cairo, Egypt
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 August 2015 Received in revised form 1 November 2015 Accepted 3 November 2015 Available online 14 November 2015
Objectives: To evaluate the long term effects of Arabic auditory training ‘AT’ programs in Egyptian schoolaged children with auditory processing disorders ‘APD’. Methods: Thirty children with APD who received the proper regular AT for minimum duration of 2 months were included. They were subjected to functional measures ‘questionnaire for APD’ and psychophysical test battery. It comprised dichotic digits, pitch pattern sequence ‘PPS’, gap in noise detection ‘GIN’ and the memory tests. New bench mark battery was applied in the form of the duration pattern, the dichotic rhyme and the informal memory tests. The results of different tests were compared across the evaluation sessions ‘pre-training, immediate post training, and the late outcome’. Results: The children were evaluated after mean duration 24.5 months, ranged 7–42 months from the end of AT. No deterioration in the scores of Arabic questionnaire or the psychophysical tests was observed compared to the immediate post training evaluation. The bench mark tests scores matched the age based norms. A statistical significant correlation existed between PPS, GIN tests and the functional measures. Conclusion: The outcome of the AT program showed long term consistency. The temporal processing tests (PPS, GIN) were sensitive tools in monitoring the progress of training. The new bench mark test battery used was effective as the diagnostic test battery in assessing the long term effects of AT program. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: APD Auditory training Long term outcome
1. Introduction Auditory processing disorder (APD) is a complex problem affecting about 7% of school aged children [1]. It refers to difficulties in the perceptual processing of auditory information in the central nervous system as demonstrated by poor performance in one or more of the auditory skills [2]. The auditory skills comprises sound localization and lateralization; auditory discrimination; auditory pattern recognition; temporal aspects of audition; auditory performance in competing acoustic signals (including dichotic listening); and auditory performance with degraded acoustic signals [3]. Although APD may coexist with other disorders (e.g., ADHD, language impairment, and learning disabilities), it is not the result of these other disorders. These disorders are not due to a deficit in the central
* Corresponding author at: Audiology Unit, ENT Dept., Faculty of Medicine, Ain Shams University, Abbassia Street, Cairo, Egypt. E-mail address: [email protected] (D. Mohamed Hassan). http://dx.doi.org/10.1016/j.ijporl.2015.11.001 0165-5876/ß 2015 Elsevier Ireland Ltd. All rights reserved.
auditory nervous system (CANS) and the listening difficulties exhibited by these children occur when co-morbidity deficit in the CANS can be demonstrated [2]. Management of APD may be viewed as a tripod with three legs that include environmental modification, compensatory strategies and direct skill remediation techniques (auditory training). Without all the three legs, the tripod cannot stand [3,4]. Auditory training ‘AT’ programs relied on the fact that the auditory system can undergo changes in response to intensive auditory training. These changes are maximal within a certain critical period of time [5]. They are classified into formal and informal programs. Coupling formal and informal auditory training should maximize treatment efficiency [6,7]. The development and implementation of AT programs in Arabic language dated since 2000. Several programs, both formal and informal, targeting nearly all the affected central processing abilities were standardized and evaluated in the Audiology Unit, Ain Shams University. Satisfactory outcome and consistent results were reported when applied on Arabic-speaking children with APD [8–11].
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The process of capturing clinical outcomes of APD has been labor intensive work but has lacked integration. Many researchers reported significant improvement after AT in children with APD [12]. The recent technical report issued by experts in the field of APD and published by ASHA pointed that additional data are needed to demonstrate the effectiveness and efficacy of these approaches [2] Preliminary findings indicated that late occurring effects of the remediation programs existed and showed improvement of skills in individuals with APD when assessed after 8 weeks of remediation [13]. Most of studies evaluating the outcome of AT programs considered a maximal period from 3 to 6 months after finishing training and not for longer periods. Tallal [14] showed consistent improvement for long term evaluation at 3 and 6 months. However, Tallal study was only on limited number of children using Fast forwards FFW. The short term consistency for the Arabic AT programs ‘up to 6 months’ was previously reported [8,9,11]. Rogowsky et al. [15] advised follow-up testing over time to determine the longer-term effects of computer-based interventions for improving reading and writing outcomes in struggling students. Future results would fill the gaps in literature and provide more definitive conclusions and recommendations about the consistency of AT programs which make real differences in the lives of children with APD and their families over longer periods [16]. Meanwhile the long term outcome of AT programs on the Egyptian children with APD has not been investigated yet. Accordingly, this study was designed to evaluate the long term effects of Arabic auditory training programs in a group of Egyptian school-aged children with APD. Those children were diagnosed with APD and received the proper intensive auditory training at time of diagnosis. Variables affecting such outcome were also highlighted. 2. Materials and methods 2.1. Subjects The present study was conducted into two steps. 2.1.1. Retrospective work up This step was done to collect data about children that could participate in the study. All files of children in the clinic for APD – Audiology Unit, El-Demerdash Hospital, Ain Shams University, Cairo – Egypt were reviewed. Four hundred children were examined during the period from 2006 to 2013. Diagnosis of APD was settled in 115 (29%) children and 40 children (35%) completed the scheduled AT program. Criteria for inclusion in the present study were settled diagnosis of APD, proper regular training at time of diagnosis. The minimum duration required for inclusion in this study was 2 months of regular therapy, twice weekly and for 30 min each. All children should have normal peripheral hearing sensitivity as shown by pure tone audiometry thresholds <15 dB HL for frequencies 500– 4000 Hz, excellent speech discrimination scores and normal middle ears functions. They had at least average psychointellectual abilities as measured by the Arabic Hiskey Nebraska test of learning aptitude with no associated neurological disorders. A group of 30 school-aged children (26 males ‘87%’ and 4 females ‘13%’) fitted the above mentioned criteria. Their mean age was 11 1/2 (2.5) years, ranged from 7 to 16 1/2 years. All children had mean intelligence quotient 87 7 and range 80–94. Twenty-six children (87%) were right handed and four children (13%) were left handed. They were enrolled in ordinary schools. Their school grades matched their chronological ages except two children. Twenty-two children (72%) were in primary grades, five (16%) in preparatory grades and the remaining three (1%) in secondary grades.
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At time of diagnosis, the majority of study group children (n = 17, 57%) had more than two affected auditory abilities; eight children had two affected abilities (26%), while one affected ability was met in five (17%). The auditory temporal processing ability was the commonest ability affected (n = 21) followed by memory disorders (n = 19) and dichotic listening disorders (n = 17). The selective auditory attention problem was seen in three subjects. Other higher cognitive communicative ability deficit in the form of phonemic awareness problem was found in 11 subjects and auditory attention problem in 1 subject (Fig. 1). All children started remediation for APD before the age of 12 years with a mean age 8 (1.8) years. Twenty-two (73%) children were trained received formal training using the Arabic computer based Arabic auditory training program ‘CBAT’ [9]. The remaining eight (27%) children received combined formal and informal training. The mean duration of training was 5.45 (3.97) months and range from 2 to 18 months. Only two children continued to receive training for 18 months as they had more than two affected central auditory abilities that necessitated long course of therapy. The CBAT program used for training of study group children was specifically implemented for treatment of Arabic-speaking children with APD and associated language learning problems [9]. It was designed according to the scientific principle of remediation to train several auditory processing abilities in a highly interesting and attractive theme [3,4,7]. The developed program was classified according to the trained auditory abilities into: (1) Bottom-up processed abilities (central auditory processing abilities) which include auditory temporal processing, selective auditory attention, auditory dichotic listening, inter-hemispheric transfer of information and auditory closure [2]. (2) Top-down processed abilities (cognitive-communicative abilities) which include auditory vigilance, auditory memory, phonological awareness and language comprehension. It consisted of three phases classified according to the used material: phase I with non-verbal material, phase II with simple verbal Arabic material, phase III with complex verbal Arabic material. Acoustic modifications were done whenever needed according to the ability trained. As an example, amplitude and frequency modulated tones with variable inter stimulus interval, prolongation of voice onset time for consonants were applied in games for auditory temporal processing disorder. Moreover, in each game the multimedia software extends to improve the visual attention and sustained visual/auditory attention together with the trained central auditory ability. This is accomplished through developing the ability to focus attention, ignore distractions, and respond quickly when stimulus changes. The program strengthens visual processing skills and sensory-motor integration through auditory to visual to motor co-ordination and fine motor skills.
Fig. 1. Distribution of study group children according to the affected auditory ability.
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2.1.2. Prospective work up It was carried out to assess the long term outcome of APD remediation and included functional measures and psychophysical APD test battery. 2.1.2.1. Functional measures. – APD questionnaire for children ‘Arabic version’ [17]. It included divided sections to assess the listening, language, memory and learning aspects. The parents answered the questions in yes or no choice. The total percent score was calculated. – The school performance of the child. It was used as guide for the child learning situation after receiving the proper APD training. It was estimated at the time of outcome evaluation of the present study and was based on the child’s certificate whether excellent (85–100%), good (70–<85), or average (50–<70). 2.1.2.2. Psychophysical CAPD test battery. Using the Arabic test battery for children [17]. This was carried out in sound treated room IAC model 1602 using two channel audiometer GrasonStadler. Inc. (GSI) Model 61 calibrated according to ANSI (1969) with a sound field testing facility. The recorded APD test materials were delivered through Cassette tape recorder with CD player via headphone or loud speaker according to the nature of the test. All tests are delivered at 50 dB SL (re: speech reception threshold). Two test batteries were applied for the study group children. The first test battery. It included some of the tests used during the APD diagnosis process and in immediate post remediation evaluation. The tests used were: dichotic digits test ‘DD’ in Arabic language [18]. Being a test for binaural integration ability, two versions were conducted and the scores were calculated as percent correct scores for each ear alone. The pitch pattern sequence test ‘PPS’ [19] with its discrimination ‘PD’ and sequencing ‘PPS’ subtests was applied to test the auditory temporal ordering and sequencing ability. The response mode was either verbal or humming and the scoring was calculated as percent correct. The gap in noise detection test ‘GIN’ [13] targeted the temporal resolution ability. The number of correct responses out of the total gaps number for each ear was estimated. Memory sub-tests in Arabic language comprised three memory subtests: recognition memory, memory for content, and memory for sequence [20]. The scoring for recognition memory was the highest score out of 11 estimated, and the highest number of words the child could repeat was scored for memory for content and memory for sequence subtests. The second battery. It was considered as bench mark tests for the evaluation of the outcome. This battery was used in order to avoid the learning effect from using tests already applied in diagnosis and in immediate post remediation evaluation. It included: duration pattern test ‘DPT’ [21] as a test for temporal ordering, the dichotic rhyme test in Arabic language ‘DRT’ [22] for the binaural integration ability. The scoring for these tests was a percent correct scores for each ear alone. The informal memory test in Arabic language [11] was also included to test the sequential memory. The materials used for the informal memory tests consisted of four lists of Arabic monosyllabic words items. The first list started with two words in sequence then the number of words increased up to five words in sequence in list ‘40 . The children had to memorize the target words in the correct sequence. The highest number of words the child could repeat in a correct sequence was calculated. An informed consent was taken from the parents of children prior to participation in the present study. The study protocol was approved by the Ethics Committee of faculty of medicine, AinShams University.
2.2. Statistical analysis Statistical analyses were performed using (SPSS) 16.0. Data were expressed as mean SD for quantitative parametric measures. The paired t-test was applied to compare between two dependent groups for parametric data. Repeated measures analysis of variance ‘ANOVA’ studied the within subjects factors across the evaluation time. The effect sizes were estimated and interpreted according to Cohen [23]. The Ranked Spearman correlation test studied the possible association between each two variables among each group for non-parametric data. The probability of error at 0.05 was considered significant. 3. Results 3.1. Immediate post remediation The immediate post remediation functional and psychophysical tests results for the study group showed marked improvement in almost all tests. Functional measures. The scores of the Arabic version of APD questionnaire significantly improved from 53 (14) % preremediation to 65 (11) % following immediate remediation (p < 0.01). Ten children (34%) improved in listening aspects, five (17%) in learning and listening, four (13%) in learning, another four in memory items and three children (10%) in language items. Improvement in all items was reported by four subjects (13%) (Fig. 2). Based on the school certificate, the mean school scores were at least good to excellent scores (n = 24, 80%) denoting acceptable scholastic performance following auditory training. Average school performance was reported in six children (20%). Some children still had difficulties in mathematical calculation (n = 3, 10%), difficulty in studying languages including Arabic, foreign languages (n = 9, 30%) and in social studies (n = 3, 10%). The parents of six children (20%) reported bad hand writing. Although better than before training, the parents of 12 children (40%) complained of poor memory. Looking to the psychophysical central test battery scores, statistical significant difference between pre and immediate post remediation evaluations in all the tests (p < 0.05). The scores approached the normal age matched 95 confidence limits (Table 1). The scores of DD tests versions improved in both ears following remediation and age matched normal values were obtained in DD version I. Meanwhile, a statistical significant higher scores in the right ear compared to left ear were noticed in DD tests. This reflected the apparent right ear advantage (REA) (Fig. 3). The PPS as a test of temporal ordering and sequencing together with temporal sequencing showed marked improvement in postremediation results although still below normative data. Similarly,
Fig. 2. Distribution of study group subjects according to the improved items in the Arabic CAPD questionnaire.
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Table 1 Mean (X), standard deviation (SD), paired t-test and p value of pre and immediate post-remediation the Arabic psychophysical tests in the study group. The age based normal 95 confidence limit ‘CL’ is displayed. Test
Pre remediation X (SD)
Post remediation X (SD)
t
p Value
95 CL [reference]
DD I-right ear ‘%’ DD I-left ear ‘%’ DD II-right ear ‘%’ DD II-left ear ‘%’ PPS test ‘%’ GIN test ‘m s’ Recognition memory ‘n’ Memory for content ‘n’ Memory for sequence ‘n’
90 (11) 81.2 (20) 79 (16) 63 (22) 39 (22) 13 (4) 7 (3) 3.5 (1) 3.3 (1)
95.3 (10) 90.6 (17) 85 (10) 4.62 64 (19) 8 (3) 10 (1.5) 4.2 (1) 4 (1)
2.69 2.74 2.28 75 (17) 3.78 8.22 7.53 6.24 6.43
0.01* 0.01* 0.03* 0.00* 0.001* 0.000* 0.000* 0.000* 0.000*
91.5–97% [18] 86.8–91.8% [18] 89–94% [18] 81.8–88% [18] 66.1–83.5% [17] 4.4–5.7 [23] 10.4 (0.4) [20] 5.5 (0.5) [20] 5 (0.5) [20]
* Statistically significant p < 0.05, the shaded cells reflected the test score within the normal 95 CL.
Table 2 Repeated measure analysis of variance and effect size across the evaluation sessions in the different tests in the study group. Test
Pre X (SD)
Immediate X (SD)
Long term outcome X (SD)
F value
p Value
Effect size
Questionnaire ‘%’ DD I-right ear ‘%’ DD I-left ear ‘%’ DD II-right ear ‘%’ DD II-left ear ‘%’ PPS test ‘%’ GIN test ‘m s’ Recognition memory ‘n’ Memory for content ‘n’ Memory for sequence ‘n’
53 (14) 90 ( 11) 81.2 (20) 79 (16) 63 (22) 39 (22) 13 (4) 7 (3) 3.5 (1) 3.2 (1)
65 (11)) 95.3 (10) 90.6 (17) 85 (10) 75 (17) 64 (19) 8 (3) 10 (1.5) 4.1 (1) 3.9(1)
77 (12) 97.2 (6) 95.7 (9.3) 88 (8.2) 79 (15.3) 69 (17.2) 7.6 (3) 10.5 (1.4) 4.7 (0.8) 4.3 (0.9)
30.1 7.1 7.9 9.7 11.1 37.5 33.5 27.5 32.2 29.1
0.000* 0.003* 0.002* 0.002* 0.000* 0.000* 0.000* 0.000* 0.000* 0.000*
0.68 0.33 0.36 0.41 0.44 0.72 0.71 0.66 0.69 0.67
Pre, pre-remediation; immediate, immediate post remediation. * Statistical significant p < 0.05; effect sizes were classified as small (0.2), medium (0.5), and large (0.8) [25].
the timing in GIN test improved and approached the normative data of their age matched norms in Arabic speaking children [24]. Fig. 3: the DD II test showing improvement in the test scores across the evaluation sessions. The difference between the right and left ear test decreased along the three sessions but with persistent statistical significant REA. 3.2. Long term evaluation outcome The study group children were evaluated for the long term effects of AT after mean duration 24.5 months 17.5 SD with a range 7–42 months from the end of APD training. The results showed no deterioration in the scores of Arabic questionnaire or the psychophysical tests compared to the immediate post training evaluation. The progression of therapy across the three evaluation sessions (pre-training, immediate post training and long term evaluation) was highlighted by repeated measure analysis of variance ‘ANOVA’ for the different tests (Table 2). Repeated measure ANOVA showed that there is significant change in the test scores across the different evaluations reflecting the significant time effect (p < 0.001). The calculated effect sizes were at least medium to large in the different tests. Follow up comparisons indicated that the pairwise difference in the scores of questionnaire, DD II ‘right ear’, PPS test, and memory for content and sequence tests showed statistical significant improvement in late outcome evaluation (Table 3). The significant increase in the scores over time reflected the consistency of the training used. In nearly all tests, marked improvement in immediate post training evaluation scores was obvious. Then the test scores tend to plateau or show mild rise along the long term evaluation reflecting the effectiveness of the training plan (Figs. 3–5). Figs. 3–5. The scores of the questionnaires, PPS, GIN and DD II test scores across the three evaluation sessions in the study group.
To exclude the effect of learning from using the same test battery for diagnosis and short term follow up, a bench mark test battery was applied. It included Arabic DRT, DPT, and informal memory test. The bench mark tests results were displayed in Table 4. The test scores in the three tests, respectively matched the age based test norms as reported by Weheiba et al. [18], Abdel Rahman et al. [26], and Tawfik et al. [11]. The effect of the different variables on the outcome of APD remediation was assessed using the ranked spearman correlation test. Neither the age nor age of starting remediation or duration of training was statistically correlated with the subjective or objective outcome tests (p > 0.5) in the present study. This pointed to the direct effect of AT programs and not the maturation or learning effect of the tests used. The consistency of the remediation program regardless the time elapsed since end of
Fig. 3. Dichotic digits II test scores.
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Table 3 Pair wise comparisons for the psychophysical tests and questionnaire across the evaluation sessions.
Questionnaire
DD I-right ear
DD I-left ear
DD II-right ear
DD II-left ear
PPS test
GIN test
Recognition memory
Memory for content
Memory for sequence
Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate Pre Pre Immediate
Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late Immediate Late Late
Mean difference
p Value
12.4 24.3 12 5.4 7.2 1.7 9.4 14.5 5.1 5.6 9 3.4 12 16 4 24.3 30 5 4.7 4.9 0.4 3 3.4 0.5 0.6 1.2 0.5 0.7 1.1 0.4
0.001* 0.000* 0.001* 0.04* 0.002* 0.89 0.03* 0.002* 0.25 0.03* 0.001* 0.008* 0.000* 0.000* 0.27 0.000* 0.000* 0.04* 0.000* 0.000* 0.2 0.000* 0.000* 0.7 0.000* 0.000* 0.001* 0.000* 0.000* 0.004*
Pre, pre-remediation; immediate, immediate post remediation; late, late outcome evaluation. * Statistical significant p < 0.05, the shaded cells reflected the tests with persistent significance improvement in scores at late outcome evaluation.
% correct scores
Evaluation time
Test
90 80 70 60 50 40 30 20 10 0 Immediate post remediation
Pre remediation
Long term evaluation
Evaluation sessions Fig. 5. PPS test scores.
Table 4 Mean (X), standard deviation (SD), range of the bench mark test battery in the study group. The age based normal 95 confidence limit ‘CL’ is displayed. Test
X
SD
95 CL [reference]
DPT ‘%’ DRT Rt ear ‘%’ DRT Lt ear ‘%’ Informal memory ‘n’
66.5 57.3 39.4 4.5
16.3 8.02 9.6 0.6
65–100% [26] 33–80% [18] 28–60% [18] 4–5 [11]
Table 5 Ranked Spearman correlation test for the function measures and the PPS, GIN tests in the study group children. Test
PPS ‘%’ GIN test ‘m s’
CAPD questionnaire
School scores
r
p
r
p
0.497 0.47
0.012* 0.022*
O.454 0.415
0.005* 0.009*
* Statistically significant p < 0.05.
100 90
% correct scores
80 70 60 50 40 30 20 10 0 Pre remediation
Immediate post remediation
Long term evaluation
Evaluation sessions
Fig. 4. CAPD questionnaire scores.
training sessions was powered by the absence of statistical correlations between the treatment outcome results (subjective or objective) and time passed till the present study. A statistical significant correlation existed between PPS, GIN tests, the CAPD questionnaire, and the school scores (p < 0.05) (Table 5). 4. Discussion In agreement with ASHA [2] and the AAA [12] guidelines in managing APD, the study group children had the proper age, language, and mentality to understand the task given for diagnosis and remediation. It was found that 25 children (83%) had more
than one affected auditory ability. The same was reported by Bellis and Ferre [27] and Cestnick and Jerger [28] who stated that APD is a heterogenous complex problem that commonly affects a group of central auditory abilities rather than affecting discrete ability. All children started AT before the age of 12 years with a mean 8 (1.8) years. Musiek and Gollegly [29] reported that the brain plasticity is maximal in young age. The variability in the duration of training in the current study could be explained by the presence of more than two affected abilities that can hinder the efficacy of therapy, making the need for longer durations of training to be considered [3,30]. Immediately following remediation, significant improvement was evident in the psychophysical APD tests as well as subjective measures. Similar results were reported by previous researches [8–11,30,31]. Although training was differing in materials used, language (English versus Arabic) and session schedules, outcome of these programs were promising. It is well known that Arabic, the official language in many countries, has very different grammar from English. Comparing the Arabic language with other languages it can be seen that most of the Arabic consonants have different frequency range than those of other languages while the differences in vowels are not significant [32]. Arabic has 28 consonants (English 24) and 8 vowels/ diphthongs (English 22) with the short vowels are unimportant in Arabic. Kamal et al. [33] found APD in 3.3% of children among the Egyptian population and in 32% among school underachievers. Chermak and Musiek [34] estimated that APD occurs in 2–3% of
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children, with a 2:1 ratio between boys and girls. The prevalence of APD in the general population has not been firmly established with rough estimates of about 5% in school aged children [35]. Notably in the present work, the psychophysical test scores approached the age norms 95 confidence limits but not the ceiling level. The right ear advantage persisted across the different sessions but with decreased differences in the late outcome evaluation reflecting the state of maturation of the corpus callosum (CC). The CC is responsible for inter hemispheric transfer of information and it continues to mature till age of 12 years [30,36]. Moreover, the REA observed in the current study reflected left hemispheric dominance for language and is typically present regardless of handedness. As emphasized by Keith and Anderson [37], the dichotic listening tests are among the most powerful AP tests for the assessment of hemispheric transfer of information, development and maturation of the central auditory nervous system. Obviously, the functional impact of APD on the child real life situations was apparent in the results of questionnaire for APD. The improvement in the questionnaire scores after remediation made it an easy outcome measure for the progress of the training. Moreover, the improvement was marked in all aspects in particular listening followed by learning tasks. Another functional measure in outcome assessment was the performance of children at school. All children were enrolled in school in grades matching their chronological age with at least good scores. Tallal [14] and Baran [38] reported better academic achievement following improvements in central auditory abilities as a direct result of AT. Although the links between them are complex, APD has a potential impact on both language learning and language use and in turn on academic achievements. On comparing the immediate post-remediation and late outcome results, better or nearly same scores for Arabic APD questionnaire and the psychophysical tests were obtained. The improvement in scores reached statistical significant levels for the scores of questionnaire, PPS test, DD II right ear, memory for content and sequence tests. This might be attributed to maturation of auditory pathway together with the effect of neuroplasticity. With repeated stimulations (training) the neural responses become stronger. The responses of the brain fibers to the stimuli used over time increases as a result of the long term potentiation (LP). This LP can be considered a form of plasticity and may be the physiologic mechanism underlying a variety of plastic processes in the nervous system, and being responsible for saving its experienced changes over long periods of time [39]. Chermak and Museik [34] reported that plasticity enables the central nervous system to accommodate and offers speech pathologists and audiologists the opportunity to improve auditory processing. Merzenich et al. [40] and Sharma et al. [41] highlighted that neuroplasticity is induced through experience and stimulation (AT) which in turn leads to reorganization (remapping) of the auditory cortex, improved synaptic efficiency, increased neural density and associated cognitive and behavioral change. The late outcome evaluation for Arabic AT programs, highlighted in the current study, proved the long term consistency of these programs in remediation Arabic speaking children with APD. Tallal and Gaab [42] reported that the outcome of AT programs is lifelong consistent. The evaluation test results of the study group children were not affected by the duration elapsed since last training received. This highlighted the consistency of the training outcome regardless the time elapsed since end of training sessions. Nevertheless, the results of the bench mark test battery pointed to the consistency of the training and excluded any learning effect from repeated evaluation. Miller et al. [43] recommended the use of test battery other than that used for diagnosis to be sure that the results obtained are direct effects of AT, and not due to habituation to the tests used. Accordingly, it is advisable to use the bench mark
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test battery in both short term and long term evaluation of AT programs. This short battery proved its efficacy and can put an end for the debate about the learning effect. It should be applied taking in consideration the age matched norms to the tests used. An important psychophysical measure in monitoring the outcome of AT was the role of temporal processing abilities. This was highlighted by the correlation between subjective measures and PPS, GIN tests. It ensured the role of this ability in detecting the progress of training. Musiek et al. [13] highlighted that GIN test and PPS test are of the few measures that are very sensitive to the therapeutic changes in the central auditory nervous system. Hence, Tallal and Gaab [42] proved that computer-based AT in school aged children improved the rate of acoustic processing and sharpen phoneme perception and phonemic awareness, all critical for reading. 5. Conclusions The outcome of the auditory training programs used for Arabicspeaking children with APD showed long term consistent improvement for periods more than 6 months up to 4 years. The Arabic questionnaire for APD and the school performance proved to be effective subjective measures for long term follow up. The temporal processing tests ‘PPS and GIN’ were sensitive tools in monitoring the progress of training. The new bench mark test battery used was as effective as the diagnostic test battery in assessing the long term effects of AT programs. The authors recommended the use of the bench mark test battery in monitoring the progress of treatment in combination with the auditory evoked potentials. Serial monitoring for the efficacy of training until stabilization of results and/or reaching the age-based normative data is mandatory. Conflicts of interest The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. Acknowledgement The contribution of children and cooperation of parents in this study was highly appreciated. References [1] D. Bamiou, N. Campbell, T. Sirimanna, Management of auditory processing disorders, Hear. Balance Commun. 4 (1) (2006) 46–56. [2] American Speech-Language-Hearing Association, (Central) Auditory Processing Disorders, Working Group on Auditory Processing Disorders, 2005 (Technical Report). Retrieved from: http://www.asha.org/docs/html/TR2005-00043.html. [3] T.J. Bellis, Assessment and Management of Central Auditory Processing Disorders in the Educational Setting: From Science to Practice, second ed., Singular, San Diego, CA, 2003. [4] G.D. Chermak, F.E. Musiek, Auditory training: principles and approaches for remediating and managing CAPD, Semin. Hear. 23 (4) (2005) 297–308. [5] B. Linkenhoker, E. Knudsen, Incremental training increases the plasticity of the auditory space map in adult bran owls, Nature 419 (2002) 293–296. [6] P. Tallal, L.S. Hirsch, T. Realpe-Bonilla, S. Miller, L.M. Brzustowicz, C. Bartlett, et al., Familial aggregation in specific language impairment, JSLHR 44 (2001) 1172–1182. [7] P. Tallal, in: G.D. Chermak, F.E. Musiek (Eds.), Foreward for: Handbook of (Central) Auditory Processing Disorder – Volume II: Comprehensive Intervention, Plural Publishing, 2006. [8] S. Tawfik, N. Hazzaa, A. Shalaby, M. Thabet, Development of an Arabic battery for remediation of selective auditory attention disorder in children, Scand. Audiol. Suppl. 52 (2001) 211–216. [9] S. Tawfik, A. Shalaby, W. El Kholi, D. Mohamed Hassan, M. Thabet, S. El Sady, et al., Development of an Arabic computer-based remediation program for children with central auditory processing disorders, in: Presented in ‘‘28th International Congress of Audiology, Innsbruck, Austria, 2006. [10] S. Tawfik, W. El Kholi, I. El Danasoury, A. Shalaby, M. Thabet, Computer-based remediation program for auditory temporal processing disorders, Sci. J. Al-Azhar Med. Fac. (Girls) 28 (2) (2007).
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