Auditory preferences of young children with and without hearing loss for meaningful auditory–visual compound stimuli

Available online at www.sciencedirect.com

Journal of Communication Disorders 42 (2009) 381–396

Auditory preferences of young children with and without hearing loss for meaningful auditory–visual compound stimuli Barbra Zupan a,*, Joan E. Sussman b,1 b

a Department of Applied Linguistics, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario, Canada L2S 3A1 Department of Communicative Disorders and Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA

Received 16 July 2008; received in revised form 3 February 2009; accepted 22 April 2009

Abstract Experiment 1 examined modality preferences in children and adults with normal hearing to combined auditory–visual stimuli. Experiment 2 compared modality preferences in children using cochlear implants participating in an auditory emphasized therapy approach to the children with normal hearing from Experiment 1. A second objective in both experiments was to evaluate the role of familiarity in these preferences. Participants were exposed to randomized blocks of photographs and sounds of ten familiar and ten unfamiliar animals in auditory-only, visual-only and auditory–visual trials. Results indicated an overall auditory preference in children, regardless of hearing status, and a visual preference in adults. Familiarity only affected modality preferences in adults who showed a strong visual preference to unfamiliar stimuli only. The similar degree of auditory responses in children with hearing loss to those from children with normal hearing is an original finding and lends support to an auditory emphasis for habilitation. Learning Outcomes: Readers will be able to (1) Describe the pattern of modality preferences reported in young children without hearing loss; (2) Recognize that differences in communication mode may affect modality preferences in young children with hearing loss; and (3) Understand the role of familiarity in modality preferences in children with and without hearing loss. # 2009 Elsevier Inc. All rights reserved.

1. Introduction When faced with a stimulus consisting of both auditory and visual cues, one modality often influences our overall perception of the stimulus more than the other. The modality that is preferred is perceived as the more important cue in a compound stimulus (Napolitano & Sloutsky, 2004). Processing preferences have been found to change across the lifespan, from an auditory preference in infants to a visual preference in adults. Young children have been identified as also demonstrating an auditory preference in processing. In fact, the auditory modality appears to dominate processing in the preschool age group to the extent that processing cues in this modality overshadows processing of visual cues (Sloutsky & Napolitano, 2003). An auditory preference in typical development may be important when considering

* Corresponding author. Tel.: +1 905 688 5550x3704; fax: +1 905 688 2360. E-mail addresses: [email protected], [email protected] (B. Zupan), [email protected] (J.E. Sussman). 1 Tel.: +1 716 829 2797x631; fax: +1 716 829 3979. 0021-9924/$ – see front matter # 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.jcomdis.2009.04.002

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treatment for children with hearing loss because therapy ranges in type from visual modality centered (i.e. sign language) to auditory modality centered (i.e. auditory–verbal therapy). 1.1. Modality preferences in young children Young children have demonstrated an auditory preference when auditory and visual information are simultaneously presented. Sloutsky and Napolitano (2003) used a modified switch design in which they first habituated four-year-old children to a training target consisting of an arbitrarily paired visual and auditory stimulus. During this habituation phase, participants were trained to select the training target when presented with a set of side-by-side audiovisual stimuli. During the test trials, children were again presented with a set of side-by-side audiovisual targets. These audiovisual stimuli included some targets in which the visual stimulus had changed and other targets in which the auditory stimulus had changed. The visual stimuli were landscape images consisting of different types of foliage and the auditory stimuli were computer-generated patterns of three simple tones. Sloutsky and Napolitano (2003) hypothesized that if the auditory stimulus carries more attentional weight in processing and is thus preferred, then children should select the stimulus set in which the auditory stimulus remained consistent with the habituated training target. Children indicated which of the two stimulus sets matched the habituated training target by pointing. Results indicated that children were more likely to attend to the auditory stimuli, relying on the auditory stimulus in their selection and failing to reject changes in the visual stimulus. This occurred even though children were able to process the visual stimuli in isolation. However, the researchers recognized that this auditory preference may have occurred due to the complexity of the visual stimuli in comparison to the auditory stimuli. In a subsequent study, the researchers used the same paradigm with a visual stimulus consisting of three green simple geometric shapes. The change in visual stimuli yielded similar results and the researchers concluded that young children fail to process visual stimuli in the presence of competing auditory stimuli. However, in a similar study, Robinson and Sloutsky (2004) found that young children switched between auditory and visual modalities depending on the nature of the visual stimulus. Although a clear auditory preference was present when a three shape pattern was used as the visual stimulus, when the pattern was simplified to a single shape, four-year-old children exhibited a visual preference. Since this shift in modality preference did not occur in infants when the visual stimulus was simplified, Robinson and Sloutsky (2004) concluded that a developmental shift in auditory preference seems to occur. Thus, infants show a consistent auditory modality preference, regardless of the nature of components of the simultaneously presented stimuli, whereas the modality preferences in young children shift depending on the complexity of the visual component of the stimulus. The familiarity of the stimulus also appears to affect modality preference in young children. Using the same modified switch design, Napolitano and Sloutsky (2004) manipulated both the complexity and familiarity of the auditory and visual stimuli in compound stimuli to examine whether modality preference was stimulus specific and dependent on the nature of each component of the compound stimulus. The visual stimuli used in this study ranged from simple geometric shapes to photographs of familiar animals and auditory stimuli included the computer generated tones used in the Sloutsky and Napolitano (2003) study as well as a series of common sounds ranging from environmental sounds (e.g. door bell) to animal sounds (e.g. dog barking). Results indicated that modality preference for young children was flexible and seemed to depend primarily on the familiarity of the stimuli. For instance, if children were unfamiliar with both the auditory and the visual stimuli, the auditory modality was preferred in processing. Alternatively, familiarity with either the visual or the auditory stimulus in the simultaneously presented pair led to preferred processing of the modality in which the familiar stimulus was presented (Napolitano & Sloutsky, 2004). Napolitano and Sloutsky (2004) also concluded that when children preferred one modality, they ignored the other modality in perception. The results of Napolitano and Sloutsky (2004) provided more insight into the flexible nature of modality dominance in young children and extended the results of Sloutsky and Napolitano (2003). However, task demands need also be considered as a contributing factor in the flexibility of the perceptual preferences found in their child participants. The general consensus of the research reviewed here suggested an auditory preference in processing for young children with some flexibility in preferences depending on the complexity and familiarity of the auditory and visual components of the compound stimulus (Napolitano & Sloutsky, 2004; Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003). However, the paradigm of each of these studies seemed to be overly complex for four-year-old children. The complexity of the task in each of these studies was evident in the low performance rates of the child participants. Furthermore, children were able to enter the test phase of each portion of the study with relatively low performance in the training phase. Specifically, children in the Sloutsky and Napolitano (2003) study were able to move to the testing phase after successful completion of

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only the final four of eight training trials (50% correct). Since the purpose of the training trials was to teach children to consistently select a particular paired auditory–visual target and make the unusual stimulus ‘familiar’, an accuracy rate of only 50% does not clearly indicate that the target stimulus was indeed familiar to the children prior to the test trials. Moreover, only 13 of the 15 children participating in the study were able to achieve a 78% success rate in the test trials. In the Robinson and Sloutsky (2004) study, children were able to move to the testing phase with only 67% success at predicting where the animal would appear. Again, given this accuracy rate, it is unclear if the target stimulus was in fact familiar. In addition, given that only 68% of the children recruited for the study met the training criterion, it is also unclear if the children remaining fully understood the complex task. The potential problem due to task complexity was evident in the number of children who needed to be excluded from the study due to their inability to pass the training sessions. Furthermore, the number of test trials for children in both studies was limited (a minimum of 12 test trials to a maximum of 36 test trials) (Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003). Finally, although modifications were made to match the complexity of the visual and auditory stimuli, much of the stimuli used were not meaningful for this young age group. The use of meaningful stimuli may affect modality preference due to attentional factors. In fact, Robinson and Sloutsky (2004) found that when visual stimuli were modified to present a single geometric shape instead of a pattern of shapes, young children demonstrated a visual modality preference instead of an auditory preference. They concluded that this shift represented flexibility in modality processing in young children (Robinson & Sloutsky, 2004). However, perhaps a single shape holds more meaning for a four-year-old than an abstract pattern of shapes. These concerns were also discussed by Napolitano and Sloutsky (2004) but the issue of overall task complexity was not addressed. Thus, to validate the results of Sloutsky and colleagues and to develop a simpler testing approach to use with children with hearing impairments, the first experiment in the current study was undertaken. The first experiment also directly manipulated the familiarity of the stimuli used with intrinsically familiar and unfamiliar tokens; the children did not have to be trained to have the tokens become familiar. 1.2. Modality preferences in children with hearing loss The issue of modality preference is an important one when considering the acquisition of language. It has been proposed that the auditory preference that occurs in infancy and early childhood is automatic and a central factor in word learning and language development (Napolitano & Sloutsky, 2004; Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003). Given this, it is important to evaluate processing preferences in children with severe to profound hearing loss who face increased challenges in auditory processing due to their impaired hearing systems. Research investigating the speech perception skills in children with hearing loss has indicated improved perception of consonants and words when presented with combined visual and auditory cues than when presented with either condition alone (Bergeson, Pisoni, & Davis, 2003; Lachs, Pisoni, & Kirk, 2001). But it is unclear which modality is contributing to the gains in speech perception since the only study that investigated modality preferences in processing in children with hearing loss found neither a preference for the visual or auditory modality. Some data suggest that visual cues could be the more predominant cues in the perception of speech for children with severe hearing impairments (Massaro & Light, 2004). Yet a more recent approach to therapy for children with hearing loss emphasizes the importance of limiting visual cues to try to strengthen what is usually the preferred channel for learning speech (the auditory pathway), particularly in the initial stages of language development (Estabrooks, 2006; Lim & Simser, 2005). This intervention, termed Auditory–Verbal Therapy (AVT), has brought forth significant controversy in the fields of education and (re)habilitation of children with hearing loss. There is a lack of empirical evidence to support this auditory technique to treatment in children with hearing loss, further fueling the controversy that surrounds the AVT approach. It is important to begin to consider how hearing loss and subsequent training approaches affect processing preferences since such preferences could ultimately affect word learning and language acquisition. Currently, there are two broad categories of therapy approaches for children with hearing loss: a form of manual communication or oral communication. Manual communication includes American Sign Language (ASL), the recognized language of deaf culture, or a form of simultaneous communication that uses signs and gestures accompanied by speech. This latter form of manual communication is referred to as total communication (TC) and promotes the use of manual communication, gesture, and lip reading with the auditory components of language (Connor, Hieber, Arts, & Zwolan, 2000). Both forms of manual communication rely heavily on the visual modality as the primary sensory channel. The category of oral communication training includes the auditory–oral (AO) and auditory–verbal therapy (AVT) approaches. Although both approaches promote early identification, maximizing

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residual hearing, and family involvement, they differ in respect to the use of visual cues. AO approaches to communication include the use of lip reading, whereas the AVT approach to therapy emphasizes the importance of limiting visual cues, including lip reading particularly in the initial stages of language development (Musselman & Kircaali-Iftar, 1996). Limiting visual cues is considered important for strengthening the auditory pathways so children with hearing loss can learn to rely on listening and spoken language as their primary communication modality (Lim & Simser, 2005). It should be emphasized however, that although visual cues are limited within the AVT approach, children are not denied access to the natural facial expressions and gestures that occur during communication interactions (Estabrooks, 2006). Research comparing these various types of communication modes is limited and the results of these studies are varied. In addition, comparisons of children with hearing loss participating in specific types of therapy to children with normal hearing are also limited. However, studies investigating audiovisual perception in children with hearing loss suggest they are able to integrate audiovisual information to maximize speech perception despite their anomalous hearing systems. For instance, Bergeson et al. (2003) examined audiovisual speech perception skills in young cochlear implant users by examining responses to auditory-only, visual-only and auditory–visual conditions in children exposed to different learning environments. These authors found that all children, regardless of their sensory and linguistic experience, had improved speech perception under the auditory–visual condition. In addition, they concluded that children who were implanted prior to 53 months of age and participating in an auditory emphasized therapy performed better in audiovisual speech perception likely due to their ability to make better use of the auditory information. The increased success of audiovisual integration of children exposed to auditory environments at a young age suggests that young children with hearing loss show similar perceptual preferences as children with normal hearing if given similar learning experiences and environments. In fact, Massaro and Light (2004) reported that listeners with hearing loss use integrated auditory and visual information just as typically hearing individuals do. This was further demonstrated by Schorr, Fox, van Wassenhove, and Knudsen (2005) who showed similar responses in young versus older cochlear implant users and age-matched hearing peers to congruent audiovisual stimuli. When stimuli consisted of an incongruent audiovisual pair (auditory /pa/ paired with visual /ka/), children using cochlear implants were less likely to report the syllable /ta/ than age-matched hearing peers. Interestingly, when children with normal hearing failed to fuse the mismatched audiovisual signal into /ta/, they reported perceiving the auditory portion of the stimulus (i.e. /pa/). This would be expected given the auditory preferences reported for this age group. Conversely, the children with hearing loss reported perceiving the visual portion of the stimulus (i.e. /ka/) when fusion failed to occur. This suggests that the visual system may be the preferred modality for processing in children using cochlear implants. Taken together, research investigating the audiovisual integration of children with hearing loss suggests that this population responds similarly to normal hearing peers when the auditory and visual information is congruent. However, if the information provided by these two modalities is incongruent, it appears that children with hearing loss are more likely to attend to the visual modality. These findings are important in light of using either auditory or visual emphasized approaches for therapy. If children with hearing loss have a natural preference for the visual modality, how is processing of auditory and visual information affected if visual cues are limited, such as in the auditory approaches to therapy (i.e. auditory–oral; AVT)? Kral (2007) suggests that early cochlear implantation leads to cross-modal reorganization and that emphasis on auditory input following cochlear implantation will maximize reorganization and thus lead to improved auditory processing. Not only does reorganization occur shortly after implantation, responses in the auditory cortex continue to grow with increased auditory input because stimulation to the implant continues to recruit auditory areas in the brain (Gordon, Papsin, & Harrison, 2003; Kral, 2007; Naito et al., 1997). This was further supported by Lee et al. (2001) who reported a correlation between the amount of visual recruitment in the auditory cortex and lower speech perception scores. However, postulations such as these need further investigation from a behavioral perspective. The current study investigates auditory preferences in young children with and without hearing loss and considers the effect of an anomalous hearing system on perceptual preferences. 1.3. Purposes of this study The literature discussed above suggests an overall auditory preference in processing in young children with normal hearing. This preference appears to be important for the purpose of language learning. Given this, it is important to consider how processing preferences are affected by a compromised hearing system. There were four purposes for the

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current investigation. The first two were addressed in Experiment 1 which examined the modality preferences in children and adults with normal hearing when presented with meaningful visual and auditory stimuli. First, the current investigation tested the validity of a simpler paradigm for exposing modality preference in speech perception. Prior research (Napolitano & Sloutsky, 2004; Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003) had used complex tasks that excluded sizeable numbers of children from participating. The child participants also had low accuracy levels in the task used. It was expected that the current Experiment 1 would find results similar to those reported by Sloutsky and Napolitano (2003), Robinson and Sloutsky (2004), and Napolitano and Sloutsky (2004) who found a general auditory preference in young children and visual preference in adults. A second objective in Experiment 1 was to test how familiarity with intrinsically familiar and unfamiliar stimuli would affect modality preference. The primary objective of Experiment 2 was to use the experimental technique from Experiment 1 and examine perceptual preferences in children with hearing loss. We wanted to determine if children with naturally deficient hearing who were using cochlear implants and participating in an auditory based therapy approach would prefer auditory stimuli and thus resemble children with normal hearing or if they would prefer visual stimuli, presumably because of their intrinsic hearing losses. All children included in the current study used cochlear implants and were participating in the AVT approach to therapy. It is known that cochlear implantation contributes to improved auditory perceptual skills for children with hearing loss yet some research suggests that this population continues to rely on visual information in processing following implantation (Schorr et al., 2005). Perceptual preferences have not been examined in pre-linguistically deaf children using cochlear implants. The current study included children exposed to the AVT technique because this approach emphasizes the auditory modality in teaching speech and language (Estabrooks, 2006; Lim & Simser, 2005). Comparing children with hearing loss participating in an auditory emphasized therapy to children with normal hearing is important when considering the influence of auditory stimulation on the development of speech and language. Research suggests that cochlear implantation leads to more normalized neural connectivity in children implanted at an early age because increased auditory stimulation leads to reorganization of the auditory cortex (Mitchell & Maslin, 2007; Ponton, Don, Eggermont, Waring, & Masuda, 1996; Schorr et al., 2005; Wolff & Thatcher, 1990). This leads one to assume that children receiving increased auditory input in their home and therapy environments should respond similarly to children with normal hearing. This assumption was the focus of Experiment 2. The objectives of Experiment 2 were as follows: (1) to examine whether children with an auditory deficit who have participated in an auditory emphasized therapy (AVT) would prefer auditory stimuli similar to children of their own age with typical hearing and (2) to examine if familiarity of the stimuli would have any influence on modality preference for these participants. 2. Experiment 1 Experiment 1 examined modality preferences in children and adults with normal hearing when presented with meaningful visual and auditory stimuli. Experiment 1 addressed task complexity issues discussed from earlier studies by using a simplified paradigm in examining modality preferences in both young children and adults. Participants in this task were presented simultaneously with an auditory and visual cue of familiar and unfamiliar animals and asked to indicate which modality best represented the animal by pointing. It was hypothesized that this simpler paradigm, using stimuli that did not need training to be familiar, might yield similar results to those presented by Sloutsky and colleagues (Napolitano & Sloutsky, 2004; Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003). Thus the inclusion of adults in this experiment was necessary in determining if similar shifts in modality preferences across the lifespan are yielded by this simpler paradigm. Experiment 1 also examined whether familiarity of the stimulus affects modality preference during simultaneous presentation of auditory and visual stimuli. Previous studies with young children (Napolitano & Sloutsky, 2004; Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003) indicated that children were more likely to attend to familiar versus unfamiliar stimuli, a result most likely due to the relevance of such stimuli in one’s environment. Napolitano and Sloutsky (2004) concluded that this preference for familiar stimuli over unfamiliar stimuli occurs regardless of the modality in which the familiar stimulus is presented. However, when both the auditory and visual stimuli are unfamiliar, children rely on the auditory modality (Napolitano & Sloutsky, 2004). This finding requires further examination due to the tasks and stimuli used previously to test modality preference. The current study addressed the issue of stimulus familiarity by using stimuli that did not require training to establish familiarity. Based on the results of Napolitano and Sloutsky (2004), it was expected that children in Experiment 1 would select the

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auditory stimulus for unfamiliar stimuli because neither the visual or auditory stimulus would be familiar. On the other hand, we expected the responses to the familiar stimuli to be variable, similar to Napolitano and Sloutsky (2004) and related to whether the visual or auditory portion of the compound stimulus was most familiar for individual children. Based on previous results on modality preferences in adults (Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003), adults were expected to pay attention to and process both the auditory and visual stimuli, but demonstrate an overall visual preference. 2.1. Method 2.1.1. Participants Twenty native speakers of North American English participated in the current study. They were divided into two groups on the basis of age: 10 young children (M = 4.02 years, SD = 0.70 years, 4 boys, 6 girls) and 10 adults (M = 25.4 years, SD = 8.82 years, 3 men, 7 women). Children with normal speech and hearing (NHC) were recruited from several local child care centers and adults with normal speech and hearing (NHA) were either the parents of the recruited children, or students enrolled at the University at Buffalo. To participate in the study, all participants had to pass a bilateral hearing screening at 20 dB HL (ANSI, 1989) for the octave frequencies between 250 and 8000 Hz and a vision screening using the Snellen Eye Chart at a distance of twenty feet. In order to meet the criterion for normal speech and language abilities, children needed to demonstrate age appropriate skills on the following tests: The Goldman Fristoe Test of Articulation-2 (GFTA-2, Goldman & Fristoe, 2000), The Token Test for Children (DiSimoni, 1978) and the Clinical Evaluation of Language Fundamentals (Wiig, Secord, & Semel, 1992). Appendix A lists the results from these tests according to child participant. Each demonstrated age appropriate skills. Adult participants reported no current or former delays in speech or language abilities. 2.1.2. Stimuli In Experiment 1, participants were exposed to photographs of familiar and unfamiliar animals paired with their corresponding sounds. Stimuli were edited so that all were 500 ms in duration and had similar peak amplitude (75 dB, SPL  2 dB) for vowels across stimuli. A list of the familiar and unfamiliar animals is provided in Table 1. The auditory stimuli used for the unfamiliar animals were not necessarily produced by those animals since some of those sounds were not available (e.g. there was no sound for hirola, an antelope-like animal). However, all sounds used were animal sounds and expected acoustic properties consistent with large versus small animals and type of animal were not violated. For example, animals that were large in size were presented with lower frequency animal sounds and a general similarity of species type was maintained. To confirm the classification of animals into familiar versus unfamiliar categories, ten additional adults with normal speech and hearing were asked to identify each animal photograph and sound. Photographs of animals determined to be familiar by the investigators were labeled by this independent group of adults with 100% accuracy. Photographs of unfamiliar animals were labeled with an average of 7% accuracy. When presented in isolation, the sounds associated with the familiar animals were more difficult to label than the photographs. However, this group of adults was able to correctly identify the sounds 90% of the time overall, well above chance levels. These results supported previous findings by Marcell, Borella, Greene, Kerr, and Rogers (2000) in a study on naming of environmental sounds. Participants in the Marcell et al. (2000) study were able to name the sounds of eight of the ten animals included in the familiar category in the current study, with at least 90% accuracy; only the items, ‘lion’ and ‘chicken’ were not included in the subset of easy-to-name sounds. However, the lion and the chicken were considered only mildly challenging since they fell just outside of the 90% accuracy range. The results of this verification task can be seen in Table 2. Because adults were only able to name photographs of unfamiliar animals with 7% accuracy and sounds with 0% accuracy, this calibration task was not extended to include young children since this age group would presumably have even less success with the unfamiliar stimuli. The 20 pairs of visual and auditory stimuli were randomized across five testing blocks for a total of 100 test trials. The photographs were taken from digital examples and presented on computer screen and were approximately 400  300 pixels in size on average. The auditory stimuli were also taken from digital examples and were presented at an average peak sound level of 75 dB SPL (C-scale—Quest model 155 sound level meter). Since children’s hearing is similar to that of adults (Werner, 1996), sound levels remained consistent for presentation of auditory stimuli for both groups of participants.

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Table 1 List of familiar and unfamiliar animals used in test portion of study. Stimuli used in test trials Training stimuli

Familiar

Unfamiliar

Bear Bee Donkey Elephant Frog Hippopotamus Monkey Mouse Seal Zebra

Bird Cat Chicken Cow Dog Duck Horse Lion Pig Sheep

Aardvark Gopher Hedgehog Hirola Marmot Meerkat Potto Weasel Wildebeest Wombat

2.1.3. Equipment All participants were seated comfortably in a sound-attenuated booth with a computer screen to the right, a speaker directly in front, and a high quality speaker to the left. Participants were seated 19 in. away from the smaller center speaker and 21 in. away from the computer screen and left speaker. The distance between the left speaker and computer screen to the center speaker was 15 in. Adults completed the task independently and children were seated next to the first investigator. A coloured picture of an ear was placed in front of the speaker and a coloured picture of an eye was placed in front of the computer screen. Participants were trained to focus their attention on the wall of the booth between these two pieces of equipment. A picture of a star was placed there to help participants focus their attention between the computer screen and the speaker between presentations of the stimuli. Visual stimuli were presented on a 14 in. flat-screen computer monitor at eye level and sounds were presented at a peak sound level of 75 dB SPL (C-weighting) through a GSI Grason–Stadler Table 2 Results of verification of classification of animals into familiar and unfamiliar categories. Ten adults were presented with 20 photographs and then 20 sounds and asked to identify the animal they saw/heard. The percentage of adults able to identify the photograph and sound is listed next to each animal. Animal

Photograph %

Sound %

Familiar Cat Chicken Cow Dog Duck Frog Horse Lion Pig Sheep

100 100 100 100 100 100 100 100 100 100

100 70 100 100 70 60 100 100 70 100

10 10 20 0 0 10 0 10 10 0

0 0 0 0 0 0 0 0 0 0

Unfamiliar Aardvark Gopher Hedgehog Hirola Marmot Meerkat Potto Tamarin Weasel Wombat

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speaker (Model #2). All instructions on how to participate in the task were provided from the computer auditorily through a center speaker to ensure continued attention to center before presentation of the stimuli. 2.1.4. Procedure Presentation of the stimuli, recording of responses and latency times were controlled by a custom developed software program (Johnson, 2004). Training was completed first and consisted of two parts. First, participants were briefly exposed to all familiar animals and asked to name them. The purpose of this task was to ensure that those animals previously categorized as familiar were identified by all participants. All participants were able to name the visual presentation of the familiar animals with 100% accuracy. Unfamiliar animals were not presented in this training phase to ensure they remained unspecified. In the second part of training, participants were given practice with the auditory–visual task using an extra set of ten animals. Participants were presented with two blocks of these animals. 80% of the 20 practice trials were auditory–visual compound stimuli (AV). The other 20% of the trials were either auditory-only (A–O) or visual-only (V–O). Prior to beginning the practice trials, the children were told they were going to play a game in which they would see and hear an animal. They were told to choose whether they liked the picture or the sound of the animal better by pointing to the picture of the eye located in front of the computer screen or the picture of the ear located in front of the speaker. Each trial included the preparatory phrase (‘Ready, here comes the animal’) followed 1000 ms later by the presentation of the stimulus. Participants were then prompted to consider a response based on their preference for the auditory or visual signal in response to the question ‘Which is the best animal?’ The word ‘animal’ was substituted with the relevant label for each stimulus presentation. A subsequent presentation of the stimulus followed immediately and participants selected their response and the corresponding button on the response box was selected. Following each trial, participants were directed to look at the star in the center to ensure that they had opportunity to attend equally to both modalities. During presentation of the stimuli, participants were not directed to look at the monitor or speaker but were not discouraged from doing so. Pictures used in the training set were not used as part of the testing stimuli. This paradigm is significantly different than the modified switch tasks presented earlier because an auditory and visual representation of the same animal was presented simultaneously, rather than using an arbitrary picture matched to an arbitrary sound. This paradigm addressed the concerns regarding complexity and intrinsic familiarity of the tokens used with the modified switch task discussed earlier. The test trials were presented immediately upon completion of the training stage and included five randomized blocks of the familiar and unfamiliar animals for a total of 100 trials. Of these trials, 79% were AV presentations, 11% were A–O presentations, and 10% were V–O presentations. Presentations of A–O and V–O stimuli were included to ensure that participants were attending to stimuli throughout the task and correctly identifying the source as visual or auditory. All task directions remained the same as those provided for the training trials. We hypothesized that if young children do in fact show an auditory modality preference, they should select the auditory stimulus, particularly for unfamiliar animals, by pointing to the speaker and picture of the ‘ear’ when asked to identify the ‘best’ animal. 2.2. Results and discussion Results of test trials were analyzed based on the percentage of auditory responses to familiar and unfamiliar stimuli. Only the AV presentations were used for analysis. However, responses to A–O conditions and V–O conditions were analyzed to verify the credibility of responses from each participant. Overall mean accuracy of responses to auditoryonly and visual-only conditions was 99.05% for adult participants and 93.81% for child participants. Individual mean accuracy responses for all participants are shown in Table 3. The reliability of responses by child participants as seen in Table 3 suggests that children were attending to the stimuli presented since they were able to consistently identify the A–O and V–O tokens with high accuracies. Fig. 1 shows mean percent auditory responses to simultaneous auditory–visual presentations for adults and children for familiar and unfamiliar stimuli. Overall, children preferred the auditory stimuli and adults preferred the visual stimuli. On average, children selected the auditory stimuli 63.3% of the time (SD = 0.16) whereas adults only selected the auditory stimuli 36.3% of the time (SD = 0.28). A one-way repeated measures ANOVA with the within-subjects factor being familiarity indicated a significant main effect for age [F(1, 18) = 18.931, p < 0.001]. All analyses were performed on arc-sine transformed data, a standard procedure employed to normalize proportional data (Winer, Brown, & Michels, 1991). Further analyses comparing number of total observed auditory responses to number of

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Table 3 Reliability of responses to auditory-only and visual-only conditions by NHA, NHC (Experiment 1) and AVT (Experiment 2) participants. NHA

NHC

AVT

Participant

% Correct

Participant

% Correct

Participant

% Correct

NHA NHA NHA NHA NHA NHA NHA NHA NHA NHA

01 02 03 04 05 06 07 08 09 10

95.24 100 95.24 100 100 100 100 100 100 100

NHC NHC NHC NHC NHC NHC NHC NHC NHC NHC

01 02 03 04 05 06 07 08 09 10

95.24 76.2 95.24 100 81 100 95.24 95.24 100 100

AVT AVT AVT AVT AVT AVT AVT AVT AVT

100 100 95 85 95 100 100 100 100

Average

99.05

Average

93.81

01 02 03 04 05 06 07 08 09

Average

97.22

auditory responses expected by chance indicated that the total number of auditory responses by children significantly exceeded chance [F(1, 9) = 8.704, p < 0.016]. Total observed auditory responses in adults also differed significantly from chance [F(1, 9) = 5.917, p < 0.038]. Familiarity of the stimuli had only a minimal affect on modality preference for children. The mean auditory response for children for familiar animals was 66.7% (SD = 0.15) and the mean auditory response for unfamiliar animals was 59.9% (SD = 0.17). The number of auditory responses for familiar versus unfamiliar animals did not significantly differ in this age group [F(1, 9) = 0.128, p < 0.728]. However, a one-way repeated measures ANOVA indicated that observed auditory responses for familiar animals significantly exceeded chance [F(1, 9) = 12.229, p < 0.007], while observed auditory responses for unfamiliar animals did not [F(1, 9) = 3.929, p < 0.079]. Familiarity did affect the responses of adult subjects. When familiar stimuli were presented, adults made near chance selections of the auditory stimuli (M = 49.6%, SD = 0.27) but when presented with unfamiliar stimuli, adults clearly preferred the visual stimuli. The visual preference for unfamiliar stimuli significantly differed from chance [F (1, 9) = 15.169, p < 0.004] and was evident in their limited selection of the auditory stimuli (M = 22.9%, SD = 0.23). Results of a one-way repeated measures ANOVA indicated a significant main effect for familiarity [F(1, 18) = 9.39, p < 0.007] in the NHA group. An interaction effect of familiar versus unfamiliar stimuli by age also reached the level of significance (F(1, 18) = 4.51, p < 0.048) showing that stimulus familiarity affected adult preferences more than it affected young children’s preferences. In the current study, young children showed a preference for auditory stimuli and adults showed a preference for visual stimuli similar to results by Sloutsky and colleagues. However, unlike the

Fig. 1. Mean auditory responses for NHA, NHC and AVT participants to familiar and unfamiliar stimuli.

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results reported by Sloutsky and colleagues, familiarity only affected modality preferences in adults who showed a more marked visual preference for unfamiliar stimuli. 3. Experiment 2 Experiment 2 examined if children with severe to profound hearing loss who use cochlear implants and receive auditory emphasized training will demonstrate preferences that are similar to children with normal hearing. Given the research in cross-modal plasticity that suggests that increased auditory exposure leads to increased reorganization of the auditory cortex, it was expected that children using cochlear implants participating in an AVT approach to therapy would have similar modality preferences to children with normal hearing. Further, it was expected that these auditory preferences would differ from those of adults in the same manner as children with normal hearing despite the fact that their sensory deficit involved the auditory and not the visual channel. However, it is possible that due to the nature of their hearing loss, children with such profound auditory deficits might naturally prefer the visual signal even though they have been involved in therapy emphasizing the auditory modality. 3.1. Method 3.1.1. Participants Nine native speakers of North American English with severe to profound hearing loss participated in the current study (M = 4.98 years; SD = 1.09; 6 boys, 3 girls). All nine children (AVT) were using the Nucleus 24 cochlear implant for at least two years and had been participating in the AVT approach for a minimum of two years. Children were recruited from centers providing the AVT approach in Ontario, Canada. Participant data is presented in Table 4. Speech and language scores were collected for all participants using standardized tests. These scores are also reported in Table 4. A tenth participant was also recruited. However, in addition to a diagnosis of sensorineural hearing loss, this child had also been diagnosed with auditory neuropathy, a condition that is thought to affect the auditory pathways between the cochlea and VIII nerve. This subsequently affects perception of auditory information differently than a pure sensorineural hearing loss. Therefore, the data for this participant was not included in data analysis. 3.1.2. Stimuli and equipment All animal pictures and sounds used for training and testing items remained the same as Experiment 1 and were presented on an Acer Tablet laptop computer in a quiet room in the child’s home, preschool or therapy setting. All responses were entered by the examiner using an alternate keyboard.

Table 4 AVT participant data. Participant Sex Age (years) Type of implant Age of activation (years) Years in AVT CELF-P receptive (PR) CELF-P expressive (PR) AVT AVT AVT AVT AVT AVT

01 02 03 04 05 06

M M M M F M

5.25 5.67 3.92 5.92 5.5 2.58

AVT 07

M

5.33

AVT 08 AVT 09

F F

4.83 5.83

Nucleus 24 Nucleus 24 Nucleus 24 Freedom Nucleus 24 Freedom Freedom Freedom Freedom Nucleus 24 Nucleus 24

2 2.5 0.92 4 1.08 0.70 1.5 1.08 (L) 4.83 (R) 3.42 3.33

3.5 2 3 2.5 4.75 2

75 1 1 1 84 a N/A

75 1 16 1 84 a N/A

4.5

37

50

3.6 3

37 9

30 9

b

a Due to age, CELF-P was not administered with AVT 06. A PR of 50 was obtained for Receptive language using the Peabody Picture Vocabulary Test (PPVT-III). b AVT 09 participated in a total communication (TC) programme prior to beginning AV therapy.

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3.1.3. Procedure The training procedure in Experiment 2 was similar to that in Experiment 1 with one small addition. In addition to naming the familiar animals, children in Experiment 2 were also required to identify the sounds of the ten familiar animals in a closed set task. Children were told that they would see three pictures of animals and hear an animal sound. They were then asked to point to the picture of the animal they heard and the examiner would enter the child’s response using a keyboard. Given the anomalous hearing systems of the participants in this experiment, this portion of training was added to Experiment 2 in order to determine the child’s accuracy with the sounds of the familiar animals. Furthermore, children were presented with only one block of the training set of animals. This block consisted of eight AV stimuli, one A–O and one V–O stimulus. Since the purpose of training was simply to accustom children to the task demands, the second block of stimuli was eliminated after completion of Experiment 1 because children did not appear to need the additional ten trials to complete the task without prompting. The testing procedure remained the same as Experiment 1. Children in Experiment 2 were presented with four randomized blocks of the ten familiar and ten unfamiliar animals for a total of 80 test trials, including 60 AV trials, and 10 trials each of the A–O and V–O stimuli. Again, single modality presentations were included to ensure reliability of responses for each participant. All directions remained the same as in Experiment 1. 3.2. Results and discussion As in Experiment 1, test trials were analyzed based on the percentage of auditory responses to the familiar and unfamiliar stimuli. Although A–O conditions and V–O conditions were analyzed to substantiate the reliability of responses for each of the participants, only the AV presentations were used for overall analysis. Children in this experiment responded to the single modality presentations with 97.22% accuracy overall indicating that the AVT group was maintaining attention throughout and knew how to respond appropriately to both auditory and visual stimuli. Reliability of responses by subject can be seen in Table 3. Analysis of the AV presentations indicated an overall preference for the auditory stimuli. On average, AVT participants selected the auditory stimuli 57.4% of the time (SD = 0.23). Although these responses did not differ significantly from chance [F(1, 8) = 1.009, p < 0.345), when these responses were compared to NHC participants in Experiment 1, no significant difference was found ( p < 0.838). Results are shown in Fig. 1. Responses to familiar versus unfamiliar stimuli were also analyzed following an arc sine transformation. Again, arc sine transformations were employed to normalize proportional data for analysis with ANOVA. Simultaneous presentations were further analyzed using a 3 (Group: AVT, NHC, NHA)  2 (Familiarity: Familiar, Unfamiliar) ANOVA. The analysis revealed a significant main effect of familiarity [F(1, 26) = 6.176, p = 0.020) which primarily reflects the influence of familiarity in adult participants. Similar to children with normal hearing, modality preference in AVT participants did not appear to be affected by familiarity. Importantly, no significant differences in response patterns between these two groups of children were found ( p = 0.838), suggesting that children with cochlear implants participating in the AVT approach have similar modality preferences to children with normal hearing. Similar to Experiment 1, a significant interaction effect of familiar versus unfamiliar stimuli by group also reached the level of significance (F(2, 26) = 3.838, p < 0.035). Additional comparisons revealed that this interaction was due to a significant difference in the influence of familiarity on response between the NHA and NHC participants ( p = 0.029). 4. General discussion The current research was designed to examine modality preferences using compound auditory and visual stimuli. This research differs from previous studies in modality preference in the paradigm used. Rather than habituating participants to an arbitrarily paired auditory–visual stimulus and then switching one of the components within the pair, we used stimuli that did not require training for familiarity and consisted of an auditory and visual representation of the same target. We felt it was important to use a simpler paradigm while investigating modality preferences, since the complexity of the task reported in previous studies of modality preference (Napolitano & Sloutsky, 2004; Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003) often led to the exclusion of child participants due to the child’s inability to reach training criterion. Since speech and language skills of the child participants in the Sloutsky et al. studies were not reported, it is unclear if the children’s inability to reach criterion was due to a general language delay or if the cognitive and attentional

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demands of the task exceeded capacity for some of the children in this age group. Experiment 1 in the current investigation aimed to investigate modality preferences in young children and adults with normal hearing using the simplified paradigm described above. Since no children needed to be excluded from Experiment 1 due to failure to understand the training task, we feel that this task was appropriate in its complexity for children between the ages of three and six years, particularly those with speech, language or hearing problems. The results of Experiment 1 primarily supported previous results in modality preference for young children (Napolitano & Sloutsky, 2004; Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003). In their exploration of underlying factors contributing to the shifting modality preferences found in young children, Napolitano and Sloutsky (2004) concluded that familiarity played an important role. Based on these results, we expected the children in Experiment 1 to choose the auditory stimulus when presented with compound auditory–visual stimuli for unfamiliar animals. This hypothesis was strongly supported. However, although we expected children’s responses to familiar stimuli to be more variable depending on familiarity with the auditory or visual components, the children in Experiment 1 still demonstrated an overall auditory preference for familiar animals. In other words, the general trend in data of the current study indicated that children seemed unaffected by the familiarity of the stimuli and consistently chose the auditory stimuli within the simultaneously presented auditory–visual stimulus. The tendency of children to choose the auditory stimulus for both familiar and unfamiliar animals merits consideration of several alternative explanations. First, unlike previous studies in modality preference, the current study uses compound stimuli that consisted of auditory and visual exemplars of the same target. Previous studies used arbitrarily paired auditory–visual stimuli so even when an ecologically valid stimulus was presented to young children (i.e. a photograph of a cat), the stimulus presented to the other modality was not meaningful (i.e. a computer generated tone). Perhaps when children are presented with meaningful compound stimuli that provide complimentary and/or redundant cues, they will focus on the modality that provides the unfamiliar portion of the stimulus. Therefore, when presented with familiar animals, the children in the current study were more attentive to the sounds of the animals because that portion of the compound stimulus was less familiar than the photograph. The nature of the auditory and visual stimuli may also have contributed to this effect since the auditory stimuli included in this study were dynamic in nature and the visual stimuli were static. The dynamic nature of the familiar auditory stimuli may have maintained attention in children and limited their processing of the visual stimulus. An alternative explanation may be that, similar to infants, children attend to a novel stimulus more often than a familiar stimulus (Dehaene-Lambertz & Dehaene, 1994). Thus, children simply found the sounds of the animals more engaging overall, regardless of how familiar the sounds were. It is likely that the sounds of the familiar animals were actually less familiar to the children than the photographs since children are often presented with simulated animal sounds and do not frequently hear real productions in their everyday environments, thus increasing the novelty of the auditory stimulus for all trials. Robinson and Sloutsky (2007) also suggest that the novelty of an auditory stimulus contributes to an auditory preference in young children because novel stimuli put increased attentional demands on children’s processing. The transient and dynamic nature of auditory information discussed above increases the challenge of processing for children with hearing loss. Children with hearing loss participating in the auditory emphasized AVT approach are specifically trained to focus on information provided through the auditory modality in order to maximize processing of auditory cues. Although research in cross-modal plasticity suggests that such emphasis may lead to increased reorganization of the auditory cortex, the auditory signal received by a cochlear implant is very different in quality than a typical acoustic signal (Kang et al., 2004). In order to assist these children in learning to rely on their anomalous auditory system for acquiring words and language, visual cues are restricted but not completely eradicated. Such restrictions are typically carried out in a natural way such as sitting beside, rather than across from, the child during therapy sessions and avoiding directing the child’s attention to the mouth for the purpose of gaining additional visual cues. By purposefully not directing children to focus on the mouth when acquiring new sounds and words, children participating in the AVT approach are taught to use their auditory systems for learning (Lim & Simser, 2005). Supporters of the AVT approach suggest that this mimics natural language learning. Given the fact that children with normal hearing do appear to prefer the auditory component of compound auditory–visual stimuli, it is important to compare the responses of the AVT participant group in Experiment 2 to those of the NHC group from Experiment 1. However, such comparisons must be approached cautiously due to the limited number of participants in this study. The small number of children with hearing loss in this study was a result of common challenges in recruitment and narrow inclusion criteria. Although this narrow inclusion criteria for both years of implant use and years in therapy was

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important for minimizing variability among participants, it resulted in a small sample size. This has been reported to be a common problem when investigating communication and speech perception in children with hearing loss (ZaidmanZait & Dromi, 2007). The results of Experiment 2 lend support to the premise that children with profound hearing impairment participating in an auditory emphasized approach can be taught to use their auditory systems for learning, similarly to children with normal hearing. Overall, the responses of the AVT participant group were very similar to those of the NHC participant group in Experiment 1. The overall rate of auditory responses for the AVT participants suggests that the training they are receiving is in fact leading them to attend to the auditory signal, even though the sensory information provided is not typical of the normal hearing system. These results are particularly interesting in lieu of the results reported by Schorr et al. (2005) which indicated that children with hearing loss tended to rely on the visual portion of a mismatched audiovisual stimulus in processing. However, communication mode was not considered or discussed in relation to perceptual preferences. Therefore, results from Schorr et al. need to be interpreted carefully. Although the auditory preference shown by the AVT participants in the current study provides support for an auditory training method, a more complete picture would be found if children trained in a TC emphasis approach could also be tested with the current techniques. Interestingly, the one child (AVT 09) who participated in another form of therapy (total communication) prior to beginning participation in the AVT approach, produced a higher number of visual responses than any of the other AVT participants, particularly for animals in the familiar category. Future research with children participating in various other forms of therapy (i.e. AO, TC) compared to AVT and children with normal hearing, also using meaningful compound auditory–visual stimuli would be of interest now that a simpler and valid technique for studying modality preference has been shown to be effective and the first results comparing a normative sample to that of children with cochlear implants has been reported. Adult responses to meaningful compound stimuli also differed from those reported in previous studies. Sloutsky and Napolitano (2003) and Robinson and Sloutsky (2004) reported a clear visual preference for familiar stimuli. However, the adults in the current study were more likely to choose the visual stimuli when the stimulus was unfamiliar. The difference between these results may be explained by the use of meaningful stimuli in this study. Unlike previous studies, the familiar stimuli used in this study were photographs of animals that are seen often in everyday environments. Due to the frequency in which these adults may encounter the familiar animals presented in the test trials, they may have found the visual stimuli of the compound less interesting than the unique pictures of the unfamiliar animals. These results indicate a similar pattern in the effects of familiarity on processing preferences as those discussed with young children. Additionally, we must also consider that visual preferences in processing act similarly to auditory preferences in terms of attentional demands. If adults show a visual preference, then unfamiliar stimuli should place greater demands on the overall processing system, thereby attenuating processing of auditory responses. Although familiar visual stimuli may initially engage the adults’ attention, they are also processed more quickly leaving adults additional time to process the auditory stimuli. This would explain the near chance selection of auditory stimuli found in the adult participants. Previous studies in modality preference found that unlike adults, children were unable to process the visual stimuli in the presence of auditory stimuli, suggesting an actual dominance in processing (Napolitano & Sloutsky, 2004; Sloutsky & Napolitano, 2003). However, throughout the course of the current investigation, children in both the NHC and AVT participant groups, made it clear that they were in fact processing both modalities when presented with these meaningful compound stimuli and were choosing the one they found most interesting. This was evident in the comments made from children regarding the modality not chosen for a particular stimulus. Furthermore, when presented with an auditory-only or visual-only stimulus, children performed accurately and at a high level. In addition, children often noted that one presentation modality was missing and correctly identified the modality in which in the presentation of an animal did not occur. Given the nature of the paradigm used in the current study, it is unclear if children processed both visual and auditory cues on the initial presentation of the bimodal stimulus or if they were able to process the less preferred modality on the second brief presentation. In addition, unlike previous studies, the auditory and visual components of the bimodal stimulus were exemplars of the same entity. Thus, the redundancy may have significantly reduced attentional demands, allowing the children to process both elements of the stimulus simultaneously. The issue of bimodal processing under conditions of decreased attentional and processing demands needs to be further investigated in future research.

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4.1. Broader implications Processing of redundant bimodal cues has important implications for children with hearing loss, particularly in terms of speech perception. The cues conveyed through the auditory and visual channels during speech are meant to be complimentary and redundant, thereby decreasing attentional demands. Speech perception is naturally assumed to be more challenging for children with hearing loss. Although this may be true, research comparing the speech perception skills of this population to children with normal hearing has indicated similar skill levels in both groups (Pisoni, 2005). Nonetheless, to our knowledge, no research has considered if the exceptional speech perception skills found in some children with hearing loss are related to similar neural circuitry as a result of increased cross-modal plasticity of the auditory cortex. Such changes in neural circuitry may underlie the increased auditory perception and may also reflect an ability to process bimodal cues similarly to children with normal hearing. Moreover, the effects of communication approach and training on cross-modal plasticity and modality preferences should also be considered. The stimuli employed in the current study were considered meaningful for young children and consisted of dynamic auditory and static visual representations of animals. It is possible that young children may have preferred the dynamic auditory signal because it was paired with static pictures rather than videos as visual stimuli. However, typical speech and language therapy routinely uses either objects or pictures in training, so the results of the current study would be expected to coincide with therapy techniques. A further study could investigate if video stimuli would be processed differently from pictures when paired with the matching dynamic auditory signal. 4.2. Conclusions The research presented here supports an overall auditory preference in young children’s perception, regardless of hearing status, and a visual preference in the perception of adults. The similar degree of auditory responses in children with profound hearing loss participating in the AVT approach to children with normal hearing was an original finding and lends support to an auditory emphasis for habilitation. If infants and young children prefer auditory stimuli in processing, then auditory approaches to training may support their learning and perhaps contribute to maintenance of the auditory function of primary and secondary cortical areas instead of their being used for visual tasks. Adults in the current study demonstrated a clear visual preference for unfamiliar stimuli. This may also have important implications when considering intervention with adults with hearing loss suggesting that the use of visual supports in learning may be advantageous for this age group. Future studies of this nature are needed to evaluate modality preferences in children and adults with anomalous auditory systems participating in various forms of (re)habilitation. Acknowledgments We express gratitude to VOICE for Hearing Impaired Children, Learning to Listen Foundation, and Speech Services Niagara for their assistance in participant recruitment. We are also grateful for comments from the reviewer and Editor for improvements to the manuscript. Appendix A Speech and language test scores for NHC participants. The token test Part 1

Part 2

CELF-P Part 3

Part 4

Part 5

Overall

(Std. score by age) NHC01, age 4:10 girls NHC02, age 4:10 girls

GFTA

Linguistic concepts

Recalling sentences

(Std. score percentile)

(Std. score percentile)

502

496

503

DNF

DNF

493a

11

63

11

63

502

505

508

512

510

512

16

98

14

91

Interdental /s/ gliding of /r/ No errors

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Appendix A (Continued ) The token test Part 1

Part 2

CELF-P Part 3

Part 4

Part 5

Overall

(Std. score by age) NHC03, age 4:10 girl NHC04, age 3:10 boy NHC05, age 3:10 girl NHC06, age 3:10 boy NHC07, age 3:06 girl NHC08, age 3:0 boy NHC09, age 3:0 girl NHC10, age 4:9 boy

GFTA

Linguistic concepts

Recalling sentences

(Std. score percentile)

(Std. score percentile)

502

501

498

504

504

503

11

63

11

63

503

503

508

507

507

507

14

91

12

75

503

500

499

503

504

502

8

25

11

63

503

504

507

503

DNF

502a

11

63

12

75

503

503

507

509

508

507

12

75

13

84

Fronting gliding of /r/ Gliding

504

500

504

DNF

497

501a

8

25

10

50

/f/ for /u/

502

507

502

501

511

506

10

50

16

98

No errors

12

75

10

50

No errors

Did not complete the token test with C10

Deaffrication /f/ for /u/ Gliding of /r/ deaffrication /f/ for /u/ Gliding of /l/

DNF: did not finish subtest, aoverall score based on raw score of completed subtests only.

Appendix B. Continuing education questions 1. Research by Sloutsky and colleagues has demonstrated that young children are flexible in their modality depending upon which of the following? a. the ecological validity of the stimuli b. the complexity of the visual stimuli c. the melody of the auditory stimuli d. the complexity of the auditory stimuli 2. It is important to compare children with hearing loss participating in auditory based therapy to children with typical hearing. True or False. 3. The McGurk effect is a phenomenon that essentially demonstrates: a. that we use only one modality in processing b. that we rely primarily on the auditory modality in processing c. that the visual modality influences our perception of auditory information d. none of the above 4. The results of the current study for children with normal hearing differed from results reported in previous studies on modality preferences in which of the following ways: a. children were found to have an auditory preference even when stimuli were familiar b. adults were found to have an auditory preference for familiar stimuli c. children were found to have a visual preference for familiar stimuli d. all of the above 5. It has been proposed that the auditory preference found in young children may be important to word learning since it leads children to attend to the human voice. True or False? References American National Standards Institute. (1989). Specifications for audiometers [ANSI S3.6-1989]. ANSI: New York. Bergeson, T. R., Pisoni, D. B., & Davis, R. A. O. (2003). A longitudinal study of audiovisual speech perception by children with hearing loss who have cochlear implants. Volta Review, 100, 53–84.

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Connor, C. M., Hieber, S., Arts, H. A., & Zwolan, T. (2000). Speech, vocabulary, and the education of children using cochlear implants: oral or total communication? Journal of Speech, Language, and Hearing Research, 35, 401–417. Dehaene-Lambertz, G., & Dehaene, S. (1994). Speed and cerebral correlates of syllable discrimination in infants. Nature, 370, 292–295. DiSimoni, F. (1978). The token test for children. Boston: Teaching Resources Corp. Estabrooks, W. (Ed.). (2006). Auditory–verbal therapy and practice. Washington: Alexander Graham Bell Association for the Deaf and Hard of Hearing, Inc.. (pp. 1–22). Goldman, R., & Fristoe, M. (2000). Test of articulation, 2nd ed.. Bloomington, MN: Pearson Assessments. Gordon, K. A., Papsin, B. C., & Harrison, R. V. (2003). Activity-dependent development plasticity of the auditory brain stem in children who use cochlear implants. Ear and Hearing, 24(6), 485–500. Johnson, K. (2004). Experiment control. Buffalo: University at Buffalo. [Computer Software]. Kang, E., Lee, D. S., Kang, H., Lee, J. S., Oh, S. H., Lee, M. C., et al. (2004). Neural changes associated with speech learning in deaf children following cochlear implantation. Neruoimage, 22, 1173–1181. Kral, A. (2007). Unimodal and cross-modal plasticity in the ‘deaf’ auditory cortex. International Journal of Audiology, 46, 479–493. Lachs, L., Pisoni, D. B., & Kirk, K. I. (2001). Use of audiovisual information in speech perception by prelingually deaf children with cochlear implants: A first report. Ear and Hearing, 22, 236–251. Lee, D. S., Lee, J. S., Oh, S. H., Kim, S. K., Kim, J. W., Chung, J.-K., et al. (2001). Cross-modal plasticity and cochlear implants. Nature, 409(6817), 149–150. Lim, S. Y. C., & Simser, J. (2005). Auditory–verbal therapy for children with hearing impairment. Annals Academy of Medicine, 34(4), 307–312. Marcell, M. M., Borella, D., Greene, M., Kerr, E., & Rogers, S. (2000). Confrontation naming of environmental sounds. Journal of Clinical and Experimental Neuropsychology, 22(6), 830–864. Massaro, D. W., & Light, J. (2004). Using visible speech to train perception and production of speech for individuals with hearing loss. Journal of Speech, Language, and Hearing Research, 47, 304–320. Mitchell, T. V., & Maslin, M. T. (2007). How vision matters for individuals with hearing loss. International Journal of Audiology, 46(9), 500–511. Musselman, C., & Kircaali-Iftar, G. (1996). The development of spoken language in deaf children: Explaining the unexplained variance. Journal of Deaf Studies and Deaf Education, 1, 108–121. Naito, Y., Hirano, O., Okazawa, H., Takahashi, H., Ishizu, K., Fujiki, N., et al. (1997). Central auditory processing of speech in cochlear implant users demonstrated by positron emission tomography. Cochlear Implant and Related Sciences Update, 52, 19–23. Napolitano, A. C., & Sloutsky, V. M. (2004). Is a picture worth a thousand words? The flexible nature of modality dominance in young children. Child Development, 75(6), 1850–1870. Pisoni, D. B. (2005). Speech perception in deaf children with cochlear implants. In D. B. Pisoni & R. E. Remez (Eds.), The handbook of speech perception (pp. 494–532). Malden, MA: Blackwell Publishing. Ponton, C. W., Don, M., Eggermont, J. J., Waring, M. D., & Masuda, A. (1996). Maturation of human cortical auditory function: Differences between normal-hearing children and children with cochlear implants. Ear and Hearing, 17(5), 430–437. Robinson, C. W., & Sloutsky, V. M. (2004). Auditory dominance and its change in the course of development. Child Development, 75(5), 1387–1401. Robinson, C. W., & Sloutsky, V. M. (2007). Visual processing speed: Effects of auditory input on visual processing. Developmental Science, 10(6), 734–740. Schorr, E. A., Fox, N. A., van Wassenhove, V., & Knudsen, E. I. (2005). Auditory–visual fusion in speech perception in children with cochlear implants. Proceedings of the National Academy of Sciences, 102(51), 18748–18750. Sloutsky, V. M., & Napolitano, A. C. (2003). Is a picture worth a thousand words? Preference for auditory modality in young children. Child Development, 74(3), 822–833. Werner, L. A. (1996). The development of auditory behavior (or what anatomists and physiologists have to explain). Ear and Hearing, 17(5), 438– 446. Wiig, E., Secord, W., & Semel, E. (1992). Clinical evaluation of language fundamentals—Preschool. USA: The Psychological Corporation, Harcourt, Brace, Jovanovich. Winer, B. J., Brown, D. R., & Michels, K. M. (1991). Statistical principles in experimental design. New York: McGraw-Hill Inc. Wolff, A. B., & Thatcher, R. W. (1990). Cortical reorganization in deaf children. Journal of Clinical Experimental Neuropsychology, 12(2), 209–221. Zaidman-Zait, A., & Dromi, E. (2007). Analagous and distinctive patterns of prelinguistic communication in children with hearing loss. Journal of Speech, Language and Hearing Research, 50, 1166–1180.