- Email: [email protected]
Benefit of contralateral hearing aid in adult cochlear implant bearers
G Model ANORL-494; No. of Pages 5
ARTICLE IN PRESS European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
Available online at
ScienceDirect www.sciencedirect.com
Original article
Benefit of contralateral hearing aid in adult cochlear implant bearers D. Bouccara a,b,∗ , E. Blanchet a,c , P.E. Waterlot a,c , M. Smadja a,b , B. Frachet a,d , B. Meyer a,b , O. Sterkers a,b,e a
Institut francilien d’implantation cochléaire (IFIC), hôpital Rothschild, Pavillon-La-Deauvillaise, 5, rue Santerre, 75012 Paris, France Otologie, implants auditifs et chirurgie de la base du crâne, groupe hospitalier de la Pitié-Salpêtrière, AP–HP, bâtiment Paul-Castaigne – 1er étage, 50-52, boulevard Vincent-Auriol, 75013 Paris, France c Laboratoire de correction auditive (LCA), 20, rue Thérèse, 75001 Paris, France d Centre de réglage des implants cochléaires, hôpital Rothschild, AP–HP, 5, rue Santerre, 75012 Paris, France e UMR-S 867 Inserm/Paris 7 Denis-Diderot, « chirurgie otologique mini-invasive robotisée », 75018 Paris, France b
a r t i c l e
i n f o
Keywords: Postlingual hearing loss Cochlear implant Hearing aid
a b s t r a c t Objectives: The present study assessed the interest of a contralateral hearing aid (HA) in adult cochlear implant (CI) bearers. Material and methods: The study recruited 10 French-speaking adult HA bearers with postlingual bilateral hearing loss, fitted for at least 2 years with a unilateral CI after loss of benefit from HA in one ear but continuing to use their contralateral HA: 4 male, 6 female; mean age, 58 years. All had regularly used bilateral HAs prior to CI. Audiometric assessment comprised: (1) individual ear hearing assessment on pure-tone audiometry and speech discrimination; and (2) free-field testing without aid, with CI only, with HA only and with CI plus HA, on pure-tone audiometry and speech discrimination with quiet background and on speech discrimination in noise. Results: Speech discrimination was significantly improved in the bimodal condition (CI plus HA) as compared to CI alone, on all tests. In quiet, discrimination for disyllabic words was > 50% in 7 cases with HA alone, in 2 cases with CI alone and in 1 case in with HA + CI. Under 0 dB signal-to-noise ratio, discrimination was > 50% in 1 case with HA alone, in 3 cases with CI alone and in 6 cases with HA + CI. Conclusion: The present results showed benefit in auditory perception in quiet and in noise with bimodal stimulation. When there is residual hearing in the non-implanted ear, a HA should be fitted; and in progressive bilateral hearing loss, CI should be suggested when HA benefit decreases in one ear. © 2015 Elsevier Masson SAS. All rights reserved.
1. Introduction Indications for cochlear implantation (CI) in adults with postlingual bilateral hearing loss are constantly evolving. Given the progress in technology and the rapid improvement in communication provided by CI, it can legitimately be suggested as soon as the benefit of a hearing aid (HA) begins to diminish in one ear. According to the French Health Authority (HAS) criteria, CI should be considered in adult bilateral HA bearers if there is only limited or no benefit of HA on one side and the patient ceases to use the device [1]. Conserved binaural hearing via bimodal stimulation (acoustic in one ear and electrical in the other) can improve speech discrimination in both quiet and noise [2].
∗ Corresponding author. Institut francilien d’implantation cochléaire (IFIC), hôpital Rothschild, Pavillon-La-Deauvillaise, 5, rue Santerre, 75012 Paris, France. E-mail address: [email protected] (D. Bouccara).
The present study was conducted in a follow-up care network for implanted patients managed in the CI departments of the Paris hospitals board (Assistance publique–Hôpitaux de Paris [AP–HP]: Avicenne, Beaujon, Pitié-Salpêtrière and Tenon-Saint-Antoine Hospitals, and the Île-de-France Region CI Institute [IFIC]), to assess results with bimodal binaural stimulation, based on audiologic tests and questionnaires. 2. Material and methods The study was performed in the IFIC as part of standard care for adult CI patients at least 2 years post-implantation. Selection was based on response to a dedicated questionnaire exploring the subjective benefit experienced with CI and contralateral HA (Appendix 1). Patients reporting benefit with continued use of their HA in association with CI were given audiologic assessment. A sample size of 10 was determined to allow the various assessments to be conducted within a 4-month period. All 10 patients were
http://dx.doi.org/10.1016/j.anorl.2015.11.002 1879-7296/© 2015 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002
G Model
ARTICLE IN PRESS
ANORL-494; No. of Pages 5
D. Bouccara et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
2 Table 1 Patient data. Patient
Age
Use of CI (years)
CI model
Hearing on HA side (dB)a
HA model
1
39
10
109
2
71
6
3
74
5
4
61
4
5
50
4
6
51
4
7
49
4
8
73
3
Phonak Senso P38 Siemens 8DF Widex C18+ Siemens Acuris Siemens Nitro CIC Siemens Centra SP Oticon Sumo DM Siemens 8DF
9
31
3
10
76
2
Cochlear Esprit 22 Cochlear Esprit 3G Med El Tempo Cochlear Esprit 3G Cochlear Freedom Cochlear Freedom Med El Pulsar Advanced Bionics Harmony Cochlear Freedom Cochlear Freedom
109 81 108 60 98 101 99 84 86
Phonak Savia 311 Phonak
HA: hearing aid; CI: cochlear implant. a Arithmetic mean of air-conduction thresholds at 500, 1000, 2000 and 4000 Hz (BIAP guideline).
French-speaking adults: 4 male, 6 female; mean age, 58 years (range, 31–76 years) (Table 1). All had postlingual bilateral hearing loss, with various etiologies. Implantation and assessment were performed in one of the study departments. All patients had been using bilateral HAs when CI was indicated due to reduced benefit on one side, and in some cases abandonment of HA use on that side, which was therefore the side on which CI was performed. Post-CI follow-up was at least 2 years. HAs and CIs were of various brands and models (Table 1). Audiometry was performed in the IFIC, using an Aurical Plus audiometer (GN Otometrics, Taastrup, Denmark) connected up to a computer running Noah software. Speech audiometry used dedicated CDs produced by the National Audioprosthetics College (Collège national d’audioprothèse; Carvin, France). Three loudspeakers were used for free-field testing: 1 frontal (0◦ ) and 2 lateral (+90◦ and −90◦ with respect to the subject). Audiometric assessment systematically comprised:
for more than 12 hours a day; this was checked on the selection questionnaire results (Appendix 2). 3.2. Residual hearing All patients had residual hearing contralaterally to the CI, with various pure-tone audiometry thresholds (Fig. 1). One patient (patient 5) had profound hearing loss without HA on one side and moderate but fluctuating loss on the other, causing problems for HA setting and use. This profile does not match the Health Authority criteria for CI, but implantation on the side with profound hearing loss was proposed due to the impact of the fluctuating deficit on everyday communication. Residual speech discrimination on the HA side, assessed by speech audiometry by headphones without aid, varied from patient to patient (Fig. 2). On the CI side, only 2 patients (patients 4 and 6) had residual hearing with
• pure-tone and speech audiometry via headphones, ear by ear, determining air-conduction thresholds for pulsed pure tones, and discrimination thresholds for Fournier’s disyllabic word lists; • free-field pure-tone audiometry, with oscillating sounds delivered without aid, with CI only, with contralateral HA only and with CI plus HA; • free-field speech audiometry in quiet, using Fournier’s disyllabic word lists, without lip-reading, delivered without aid, with CI only, with contralateral HA only and with CI plus HA; • speech audiometry in noise, using Hint’s sentence lists on CD, with “cocktail party” noise, delivered without aid, with CI only, with contralateral HA only and with CI plus HA. The signal was presented frontally and the noise laterally; signal level was 60 dB (SPL) and the signal/noise ratio ranged between −20 and +20 dB.
3. Results 3.1. Clinical Table 1 presents the main clinical data for the series of 10 adults, aged 31 to 76 years (mean, 58 years), with a mean post-CI followup of 4.5 years. All were using unilateral CI with contralateral HA,
Fig. 1. Residual hearing contralateral to CI: severe to profound hearing loss on puretone audiometry.
Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002
G Model
ARTICLE IN PRESS
ANORL-494; No. of Pages 5
D. Bouccara et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
Fig. 2. Residual hearing contralateral to CI: speech audiometry via headphones without aid.
thresholds > 100 dB at all frequencies, without effective discrimination (data not shown). 3.3. Benefit of contralateral HA The HA on the non-implanted side, if used alone without the CI, provided a certain gain in discrimination in quiet for most patients: 100% in 4 cases, 50–100% in 6 and < 50% in 4 (Table 2). 3.4. Benefit of CI Using the CI, thresholds on free-field pure-tone audiometry were comparable for all patients (data not shown). Speech discrimination showed benefit with CI only in quiet; all patients had 100% discrimination (Table 2). 3.5. CI plus HA Associating CI and HA in quiet did not change the discrimination achieved with CI alone: i.e., no impairment resulting from adding the HA (Table 2). This indicates a ceiling effect, with no difference between the CI and CI + HA conditions at the intensity level used for the disyllabic word tests. Discrimination in noise varied widely from patient to patient, according to signal-to-noise ratio, with CI or HA alone or associated. In 20% of cases (n = 2), HA + CI in noise provided poorer results than CI alone (Table 3). In 1 case (patient 6), HA + CI provided poorer results than HA alone. 4. Discussion Progress in surgical techniques and in signal coding applied to cochlear implants have broadened the indications for CI. Originally reserved to total or subtotal bilateral hearing loss, CI is now used in Table 2 Speech audiometry results: maximum free-field speech discrimination with hearing aid (HA), cochlear implant (CI) and hearing aid plus contralateral implant, in quiet. Patient
HA quiet
CI quiet
HA + CI quiet
1 2 3 4 5 6 7 8 9 10
20 40 100 40 100 100 100 0 80 60
100 100 100 100 100 100 100 100 100 100
100 100 100 100 100 100 100 100 100 100
HA: hearing aid; CI: cochlear implant.
3
cases of ≤ 50% speech discrimination on free-field speech audiometry at 60 dB with optimally tuned HAs. There is no upper age limit to CI in adults, unless cognitive impairment is found. In fluctuating hearing loss, CI may be considered when the frequency and duration of fluctuation have a major impact on communication. These points were laid out in a report by the French Health Authority (HAS) [1]. The aim of CI with contralateral HA is to conserve binaural hearing, with improved speech perception in noise and spatial location, alleviating the squelch, head-shadow and summation effects. The contralateral HA provides bimodal hearing to which acoustic stimulation contributes frequency and spectrum information that improves prosody and musical perception and voice recognition. The present study, however, found the contribution of the HA to be in some cases limited or negative in noise. The relevant factors may be multiple: duration and asymmetry of hearing loss, and neural plasticity. The literature testifies to the interest of CI + HA bimodal stimulation. In a retrospective study of 7 adults with postlingual hearing loss, a mean age of 59 years and a mean 2 years’ post-CI followup, Hamzavi et al. compared speech recognition (lists of numbers, monosyllabic words and sentences) using CI alone and CI + HA, and reported benefit with bimodal stimulation: whether for numbers (83% recognition with CI vs. 89% with CI + HA), monosyllabic words (37% vs. 49%) or sentences (79% vs. 88%), bimodal stimulation was advantageous in quiet situations [3]. In a multicenter study of 12 adults serving as their own controls (pre- vs. post-CI), Morera et al. reported benefit with CI + HA at 6 months post-CI, including in noise (signal/noise ratio, 10 dB) [2]. Ching et al., in a study of 21 adults, reported benefit with CI + HA over CI alone and especially over HA alone; comparing spatial location with CI alone, HA alone and CI + HA, the best results were obtained with the CI + HA association [4]. Luntz et al. demonstrated that performance under bimodal stimulation improves with time: in a prospective study with several months’ follow-up in 2 sessions at a minimum 6-month interval, performance in noise (10 dB ratio) improved with the association CI + HA, and progressed over the first year post-CI [5]. Firszt et al., in a case report and review of the literature, detailed the advantages of bimodal stimulation in terms of speech discrimination in noise and of spatial location [6]. Recent studies reported that combining HA and CI quantitatively improved performance, especially when low-frequency thresholds (< 500 Hz) on the HA side were sufficiently conserved [7,8]. Studies of children with CI found a qualitative impact of bimodal (CI + HA) stimulation [9,10]. Bimodal electric plus acoustic stimulation in a single ear by means of an electro-acoustic implant showed possible benefit in terms of speech discrimination in noise and listening to music [11,12]. More generally, prolonged HA use during the period of profound hearing loss before CI has been shown to be a favorable prognostic factor for benefit with CI [13]. Particular attention should be paid to HA settings, taking account of bimodality in adapting gain per frequency band [14,15]. Certain manufacturers recommend particular procedures and tuning programs [16]. The present study confirmed the above findings and the attitude favoring CI as soon as HA benefit diminishes or ceases in progressive postlingual hearing loss. In some of the present patients, HA benefit was beyond the official HAS criteria for CI, which was nevertheless proposed due to the progressive nature of the bilateral hearing loss. This strategy helps limit the duration of binaural hearing loss and boosts the information input of both the HA and the CI in the most difficult conditions of noisy surroundings. The results of the study questionnaire regarding general benefit in terms of hearing quality encourage continuing with the CI + HA association. The questionnaire was developed purely to supplement the audiological data in the study, and should be revised to make it more finely targeted or completed by other questionnaires used in auditory rehabilitation (APHAB, GBI).
Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002
G Model
ARTICLE IN PRESS
ANORL-494; No. of Pages 5
D. Bouccara et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
4
Table 3 Speech audiometry results: maximum free-field speech discrimination with hearing aid (HA), cochlear implant (CI) and hearing aid plus contralateral implant, in noise, with signal/noise ratios +5 and 0. Patient
HA noise S/N: +5a
CI noise S/N: +5
HA + CI noise S/N: +5
HA noise S/N: 0a
CI noise S/N: 0a
HA + CI noise S/N: 0
1 2 3 4 5 6 7 8 9 10 Mean (SD)
0 0 0 0 0 80 20 0 0 0 ND
0 60 60 80 100 70 0 20 20 60 47 (34.6)
40 80 80 60 100 100 40 80 60 100 74 (23.2)
0 0 0 0 0 80 0 0 0 0 ND
0 20 0 0 20 0 0 0 0 0 ND
20 0 0 0 20 40 0 0 40 100 24.4 (32.8)
a
HA in noise with S/N +5, HA in noise with S/N 0, and CI in noise with S/N 0: zero discrimination for most patients, means non-determined.
Bilateral CI is an alternative to acoustic stimulation contralateral to the CI. Studies have shown that simultaneous CI in profound or total bilateral hearing loss improves speech discrimination in noise, even when results differ between the two ears. A study demonstrated that no preoperative factors predict CI benefit in either ear [17]. The choice between uni- or bilateral implantation, either simultaneous or successive, is thus individual, depending mainly on residual hearing in one ear and on the benefit obtained with the HA; it should take account of the fact that simultaneous bilateral implantation is followed by complete loss of speech comprehension during the activation and setting phase except in case of conserved hearing and bimodal stimulation: electric for high and acoustic for low frequencies, using an electro-acoustic implant. In case of residual hearing, even when HA performance is limited, CI provides benefit only after a few months, during which the patient will be in difficulty if implantation was bilateral, no longer having the benefit of the HA in the better ear. What then is the benefit of bilateral CI over CI + HA? A further study of performance in bilateral CI under the same conditions as in the present study would be useful to determine indications for sequential bilateral CI according to the benefit obtained during the transitional bimodal CI + HA phase.
• all the time? • just in some circumstances? • if so, which? If not, why did you stop? 2. Why do you wear your hearing aid? -
It improves my understanding of speech in silence Yes/No It improves my understanding of speech in noise Yes/No It improves my recognition of familiar sounds Yes/No It lets me hear on both sides and locate sounds better Yes/No It’s reassuring Yes/No It makes hearing more comfortable Yes/No Do you think wearing your hearing aid: ◦ made it easier to adapt to the cochlear implant? Yes/No ◦ made it take longer to progress with your cochlear implant? Yes/No ◦ complements your cochlear implant? Yes/No
3. Since you got your cochlear implant, do you reset your hearing aid regularly? Yes/No
5. Conclusion Technological progress in signal processing applied to cochlear implants has broadened the indications for CI. The present study, in adults with more or less rapidly progressive postlingual hearing loss, demonstrated the interest of performing CI as soon HA benefit diminishes, so as to conserve binaural hearing. Disclosure of interest The authors declare that they have no competing interest.
How often? Were you advised to? Yes/No 4. Do you think the cochlear implant has affected your hearing in the other ear? Yes/No - worsening it Yes/No - improving it Yes/No 5. Are you: right-handed? Yes/No
left-handed? Yes/No
Acknowledgments The authors thank Dr Evelyne Ferrary for finalizing the present paper.
Appendix 2. Questionnaire results for the 10 patients
Appendix 1. Pre-inclusion questionnaire (selection criterion) 1. Since you got your cochlear implant, have you still been wearing your hearing aid in the other ear? Yes/No If yes, do you wear it: Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002
G Model ANORL-494; No. of Pages 5
ARTICLE IN PRESS D. Bouccara et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
References [1] Traitement de la surdité par pose d’implants cochléaires ou d’implants du tronc cérébral. Rapport de la Haute Autorité de Santé; 2007 http://www.has-sante. fr/portail/upload/docs/application/pdf/rapport implants cochleaires.pdf. [2] Morera C, Manrique M, Ramos A, Garcia-Ibanez L, Cavalle L. Advantages of binaural hearing provided through bimodal stimulation via a cochlear implant and a conventional hearing aid: a 6 month comparative study. Acta Otolaryngol 2005;125(6):596–606. [3] Hamzavi J, Pok SM, Gstoettner W, Baumgartner WD. Speech perception with a cochlear implant used in conjuction with a hearing aid in the opposite ear. Int J Audiol 2004;43:61–5. [4] Ching TY, Incerti P, Hill M. Binaural benefits for adults who use hearing aids and cochlear implants in opposite ears. Ear Hear 2004;25:9–21. [5] Luntz M, Shpak T, Weiss H. Binaural-bimodal hearing: concomitant use of a unilateral cochlear implant and a controlateral hearing aid. Acta Otolaryngol 2005;125:863–9. [6] Firszt JB, Reeder RM, Skinner MW. Restoring hearing symmetry with two cochlear implants or one cochlear implant and a contralateral hearing aid. J Rehabil Res Dev 2008;45:749–67. [7] Ilg A, Bojanowicz M, Lesisnski- Schiedat A, Lenarz T, Bûchner A. Evaluation of the bimodal benefit in a large cohort of cochlear implant subjects using a contralateral hearing aid. Otol Neurotol 2014:23. [8] Shpak T, Most T, Luntz M. Fundamental frequency information for speech recognition via bimodal stimulation: cochlear implant in one ear and hearing aid in the other. Ear Hear 2014;35:97–109. [9] Hegarty L, Faulkner A. The perception of stress and intonation in children with cochlear implant and a hearing aid. Cochlear Implants Int 2013;14:S35–9, http://dx.doi.org/10.1179/1467010013.Z.
5
[10] Bartov T. Most T.song recognition by young children with cochlear implants: comparison between unilateral, bilateral and bimodal users. J Speech Lang Hear Res 2014;57:1929–41. [11] Fraysse B, Macías AR, Sterkers O, Burdo S, et al. Residual hearing conservation and electroacoustic stimulation with the nucleus 24 contour advance cochlear implant. Otol Neurotol 2006;27:624–33. [12] El Fata F, James CJ, Laborde ML, Fraysse B. How much residual hearing is ‘useful’ for music perception with cochlear implants? Audiol Neurootol 2009; 14(Suppl. 1):14–21. [13] Lazard D, Vincent C, Venail F, Van de Heyning P, Truy E, et al. Pre-, perand postoperative factors affecting performance of postlinguistically deaf adults using cochlear implants: a new conceptual model over time. PLoS One 2012;7(11):e48739, http://dx.doi.org/10.1371/journal.pone.0048739 [epub 2012 Nov]. [14] Neuman AC, Svirsky MA. Effect of hearing aid brandwidth on speech recognition performance of listeners using a cochlear implant and contralateral hearing aid (bimodal hearing). Ear Hear 2013;34:553–61. [15] Yehudai N, Shpak T, Most T, Luntz M. Functionnal status of hearing AIDS in bilateral-bimodal users. Otol Neurootol 2013;34:675–81. [16] Francart T, Mc Dermott H. Speech perception and localisation with SCORE bimodal: a loudness normalisation strategy for combined cochlear implant and hearing aid stimulation. PLoS One 2012;7(10):e45385, http://dx.doi.org/ 10.1371/journal.pone.0045385 [epub 2012 Oct 24]. [17] Mosnier I, Sterkers O, Bébéar JP, Godey B, et al. Speech performances and sound localization in complex noisy environment in bilaterally implanted adult patients. Audiol Neurootol 2009;14:106–14.
Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002
ARTICLE IN PRESS European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
Available online at
ScienceDirect www.sciencedirect.com
Original article
Benefit of contralateral hearing aid in adult cochlear implant bearers D. Bouccara a,b,∗ , E. Blanchet a,c , P.E. Waterlot a,c , M. Smadja a,b , B. Frachet a,d , B. Meyer a,b , O. Sterkers a,b,e a
Institut francilien d’implantation cochléaire (IFIC), hôpital Rothschild, Pavillon-La-Deauvillaise, 5, rue Santerre, 75012 Paris, France Otologie, implants auditifs et chirurgie de la base du crâne, groupe hospitalier de la Pitié-Salpêtrière, AP–HP, bâtiment Paul-Castaigne – 1er étage, 50-52, boulevard Vincent-Auriol, 75013 Paris, France c Laboratoire de correction auditive (LCA), 20, rue Thérèse, 75001 Paris, France d Centre de réglage des implants cochléaires, hôpital Rothschild, AP–HP, 5, rue Santerre, 75012 Paris, France e UMR-S 867 Inserm/Paris 7 Denis-Diderot, « chirurgie otologique mini-invasive robotisée », 75018 Paris, France b
a r t i c l e
i n f o
Keywords: Postlingual hearing loss Cochlear implant Hearing aid
a b s t r a c t Objectives: The present study assessed the interest of a contralateral hearing aid (HA) in adult cochlear implant (CI) bearers. Material and methods: The study recruited 10 French-speaking adult HA bearers with postlingual bilateral hearing loss, fitted for at least 2 years with a unilateral CI after loss of benefit from HA in one ear but continuing to use their contralateral HA: 4 male, 6 female; mean age, 58 years. All had regularly used bilateral HAs prior to CI. Audiometric assessment comprised: (1) individual ear hearing assessment on pure-tone audiometry and speech discrimination; and (2) free-field testing without aid, with CI only, with HA only and with CI plus HA, on pure-tone audiometry and speech discrimination with quiet background and on speech discrimination in noise. Results: Speech discrimination was significantly improved in the bimodal condition (CI plus HA) as compared to CI alone, on all tests. In quiet, discrimination for disyllabic words was > 50% in 7 cases with HA alone, in 2 cases with CI alone and in 1 case in with HA + CI. Under 0 dB signal-to-noise ratio, discrimination was > 50% in 1 case with HA alone, in 3 cases with CI alone and in 6 cases with HA + CI. Conclusion: The present results showed benefit in auditory perception in quiet and in noise with bimodal stimulation. When there is residual hearing in the non-implanted ear, a HA should be fitted; and in progressive bilateral hearing loss, CI should be suggested when HA benefit decreases in one ear. © 2015 Elsevier Masson SAS. All rights reserved.
1. Introduction Indications for cochlear implantation (CI) in adults with postlingual bilateral hearing loss are constantly evolving. Given the progress in technology and the rapid improvement in communication provided by CI, it can legitimately be suggested as soon as the benefit of a hearing aid (HA) begins to diminish in one ear. According to the French Health Authority (HAS) criteria, CI should be considered in adult bilateral HA bearers if there is only limited or no benefit of HA on one side and the patient ceases to use the device [1]. Conserved binaural hearing via bimodal stimulation (acoustic in one ear and electrical in the other) can improve speech discrimination in both quiet and noise [2].
∗ Corresponding author. Institut francilien d’implantation cochléaire (IFIC), hôpital Rothschild, Pavillon-La-Deauvillaise, 5, rue Santerre, 75012 Paris, France. E-mail address: [email protected] (D. Bouccara).
The present study was conducted in a follow-up care network for implanted patients managed in the CI departments of the Paris hospitals board (Assistance publique–Hôpitaux de Paris [AP–HP]: Avicenne, Beaujon, Pitié-Salpêtrière and Tenon-Saint-Antoine Hospitals, and the Île-de-France Region CI Institute [IFIC]), to assess results with bimodal binaural stimulation, based on audiologic tests and questionnaires. 2. Material and methods The study was performed in the IFIC as part of standard care for adult CI patients at least 2 years post-implantation. Selection was based on response to a dedicated questionnaire exploring the subjective benefit experienced with CI and contralateral HA (Appendix 1). Patients reporting benefit with continued use of their HA in association with CI were given audiologic assessment. A sample size of 10 was determined to allow the various assessments to be conducted within a 4-month period. All 10 patients were
http://dx.doi.org/10.1016/j.anorl.2015.11.002 1879-7296/© 2015 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002
G Model
ARTICLE IN PRESS
ANORL-494; No. of Pages 5
D. Bouccara et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
2 Table 1 Patient data. Patient
Age
Use of CI (years)
CI model
Hearing on HA side (dB)a
HA model
1
39
10
109
2
71
6
3
74
5
4
61
4
5
50
4
6
51
4
7
49
4
8
73
3
Phonak Senso P38 Siemens 8DF Widex C18+ Siemens Acuris Siemens Nitro CIC Siemens Centra SP Oticon Sumo DM Siemens 8DF
9
31
3
10
76
2
Cochlear Esprit 22 Cochlear Esprit 3G Med El Tempo Cochlear Esprit 3G Cochlear Freedom Cochlear Freedom Med El Pulsar Advanced Bionics Harmony Cochlear Freedom Cochlear Freedom
109 81 108 60 98 101 99 84 86
Phonak Savia 311 Phonak
HA: hearing aid; CI: cochlear implant. a Arithmetic mean of air-conduction thresholds at 500, 1000, 2000 and 4000 Hz (BIAP guideline).
French-speaking adults: 4 male, 6 female; mean age, 58 years (range, 31–76 years) (Table 1). All had postlingual bilateral hearing loss, with various etiologies. Implantation and assessment were performed in one of the study departments. All patients had been using bilateral HAs when CI was indicated due to reduced benefit on one side, and in some cases abandonment of HA use on that side, which was therefore the side on which CI was performed. Post-CI follow-up was at least 2 years. HAs and CIs were of various brands and models (Table 1). Audiometry was performed in the IFIC, using an Aurical Plus audiometer (GN Otometrics, Taastrup, Denmark) connected up to a computer running Noah software. Speech audiometry used dedicated CDs produced by the National Audioprosthetics College (Collège national d’audioprothèse; Carvin, France). Three loudspeakers were used for free-field testing: 1 frontal (0◦ ) and 2 lateral (+90◦ and −90◦ with respect to the subject). Audiometric assessment systematically comprised:
for more than 12 hours a day; this was checked on the selection questionnaire results (Appendix 2). 3.2. Residual hearing All patients had residual hearing contralaterally to the CI, with various pure-tone audiometry thresholds (Fig. 1). One patient (patient 5) had profound hearing loss without HA on one side and moderate but fluctuating loss on the other, causing problems for HA setting and use. This profile does not match the Health Authority criteria for CI, but implantation on the side with profound hearing loss was proposed due to the impact of the fluctuating deficit on everyday communication. Residual speech discrimination on the HA side, assessed by speech audiometry by headphones without aid, varied from patient to patient (Fig. 2). On the CI side, only 2 patients (patients 4 and 6) had residual hearing with
• pure-tone and speech audiometry via headphones, ear by ear, determining air-conduction thresholds for pulsed pure tones, and discrimination thresholds for Fournier’s disyllabic word lists; • free-field pure-tone audiometry, with oscillating sounds delivered without aid, with CI only, with contralateral HA only and with CI plus HA; • free-field speech audiometry in quiet, using Fournier’s disyllabic word lists, without lip-reading, delivered without aid, with CI only, with contralateral HA only and with CI plus HA; • speech audiometry in noise, using Hint’s sentence lists on CD, with “cocktail party” noise, delivered without aid, with CI only, with contralateral HA only and with CI plus HA. The signal was presented frontally and the noise laterally; signal level was 60 dB (SPL) and the signal/noise ratio ranged between −20 and +20 dB.
3. Results 3.1. Clinical Table 1 presents the main clinical data for the series of 10 adults, aged 31 to 76 years (mean, 58 years), with a mean post-CI followup of 4.5 years. All were using unilateral CI with contralateral HA,
Fig. 1. Residual hearing contralateral to CI: severe to profound hearing loss on puretone audiometry.
Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002
G Model
ARTICLE IN PRESS
ANORL-494; No. of Pages 5
D. Bouccara et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
Fig. 2. Residual hearing contralateral to CI: speech audiometry via headphones without aid.
thresholds > 100 dB at all frequencies, without effective discrimination (data not shown). 3.3. Benefit of contralateral HA The HA on the non-implanted side, if used alone without the CI, provided a certain gain in discrimination in quiet for most patients: 100% in 4 cases, 50–100% in 6 and < 50% in 4 (Table 2). 3.4. Benefit of CI Using the CI, thresholds on free-field pure-tone audiometry were comparable for all patients (data not shown). Speech discrimination showed benefit with CI only in quiet; all patients had 100% discrimination (Table 2). 3.5. CI plus HA Associating CI and HA in quiet did not change the discrimination achieved with CI alone: i.e., no impairment resulting from adding the HA (Table 2). This indicates a ceiling effect, with no difference between the CI and CI + HA conditions at the intensity level used for the disyllabic word tests. Discrimination in noise varied widely from patient to patient, according to signal-to-noise ratio, with CI or HA alone or associated. In 20% of cases (n = 2), HA + CI in noise provided poorer results than CI alone (Table 3). In 1 case (patient 6), HA + CI provided poorer results than HA alone. 4. Discussion Progress in surgical techniques and in signal coding applied to cochlear implants have broadened the indications for CI. Originally reserved to total or subtotal bilateral hearing loss, CI is now used in Table 2 Speech audiometry results: maximum free-field speech discrimination with hearing aid (HA), cochlear implant (CI) and hearing aid plus contralateral implant, in quiet. Patient
HA quiet
CI quiet
HA + CI quiet
1 2 3 4 5 6 7 8 9 10
20 40 100 40 100 100 100 0 80 60
100 100 100 100 100 100 100 100 100 100
100 100 100 100 100 100 100 100 100 100
HA: hearing aid; CI: cochlear implant.
3
cases of ≤ 50% speech discrimination on free-field speech audiometry at 60 dB with optimally tuned HAs. There is no upper age limit to CI in adults, unless cognitive impairment is found. In fluctuating hearing loss, CI may be considered when the frequency and duration of fluctuation have a major impact on communication. These points were laid out in a report by the French Health Authority (HAS) [1]. The aim of CI with contralateral HA is to conserve binaural hearing, with improved speech perception in noise and spatial location, alleviating the squelch, head-shadow and summation effects. The contralateral HA provides bimodal hearing to which acoustic stimulation contributes frequency and spectrum information that improves prosody and musical perception and voice recognition. The present study, however, found the contribution of the HA to be in some cases limited or negative in noise. The relevant factors may be multiple: duration and asymmetry of hearing loss, and neural plasticity. The literature testifies to the interest of CI + HA bimodal stimulation. In a retrospective study of 7 adults with postlingual hearing loss, a mean age of 59 years and a mean 2 years’ post-CI followup, Hamzavi et al. compared speech recognition (lists of numbers, monosyllabic words and sentences) using CI alone and CI + HA, and reported benefit with bimodal stimulation: whether for numbers (83% recognition with CI vs. 89% with CI + HA), monosyllabic words (37% vs. 49%) or sentences (79% vs. 88%), bimodal stimulation was advantageous in quiet situations [3]. In a multicenter study of 12 adults serving as their own controls (pre- vs. post-CI), Morera et al. reported benefit with CI + HA at 6 months post-CI, including in noise (signal/noise ratio, 10 dB) [2]. Ching et al., in a study of 21 adults, reported benefit with CI + HA over CI alone and especially over HA alone; comparing spatial location with CI alone, HA alone and CI + HA, the best results were obtained with the CI + HA association [4]. Luntz et al. demonstrated that performance under bimodal stimulation improves with time: in a prospective study with several months’ follow-up in 2 sessions at a minimum 6-month interval, performance in noise (10 dB ratio) improved with the association CI + HA, and progressed over the first year post-CI [5]. Firszt et al., in a case report and review of the literature, detailed the advantages of bimodal stimulation in terms of speech discrimination in noise and of spatial location [6]. Recent studies reported that combining HA and CI quantitatively improved performance, especially when low-frequency thresholds (< 500 Hz) on the HA side were sufficiently conserved [7,8]. Studies of children with CI found a qualitative impact of bimodal (CI + HA) stimulation [9,10]. Bimodal electric plus acoustic stimulation in a single ear by means of an electro-acoustic implant showed possible benefit in terms of speech discrimination in noise and listening to music [11,12]. More generally, prolonged HA use during the period of profound hearing loss before CI has been shown to be a favorable prognostic factor for benefit with CI [13]. Particular attention should be paid to HA settings, taking account of bimodality in adapting gain per frequency band [14,15]. Certain manufacturers recommend particular procedures and tuning programs [16]. The present study confirmed the above findings and the attitude favoring CI as soon as HA benefit diminishes or ceases in progressive postlingual hearing loss. In some of the present patients, HA benefit was beyond the official HAS criteria for CI, which was nevertheless proposed due to the progressive nature of the bilateral hearing loss. This strategy helps limit the duration of binaural hearing loss and boosts the information input of both the HA and the CI in the most difficult conditions of noisy surroundings. The results of the study questionnaire regarding general benefit in terms of hearing quality encourage continuing with the CI + HA association. The questionnaire was developed purely to supplement the audiological data in the study, and should be revised to make it more finely targeted or completed by other questionnaires used in auditory rehabilitation (APHAB, GBI).
Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002
G Model
ARTICLE IN PRESS
ANORL-494; No. of Pages 5
D. Bouccara et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
4
Table 3 Speech audiometry results: maximum free-field speech discrimination with hearing aid (HA), cochlear implant (CI) and hearing aid plus contralateral implant, in noise, with signal/noise ratios +5 and 0. Patient
HA noise S/N: +5a
CI noise S/N: +5
HA + CI noise S/N: +5
HA noise S/N: 0a
CI noise S/N: 0a
HA + CI noise S/N: 0
1 2 3 4 5 6 7 8 9 10 Mean (SD)
0 0 0 0 0 80 20 0 0 0 ND
0 60 60 80 100 70 0 20 20 60 47 (34.6)
40 80 80 60 100 100 40 80 60 100 74 (23.2)
0 0 0 0 0 80 0 0 0 0 ND
0 20 0 0 20 0 0 0 0 0 ND
20 0 0 0 20 40 0 0 40 100 24.4 (32.8)
a
HA in noise with S/N +5, HA in noise with S/N 0, and CI in noise with S/N 0: zero discrimination for most patients, means non-determined.
Bilateral CI is an alternative to acoustic stimulation contralateral to the CI. Studies have shown that simultaneous CI in profound or total bilateral hearing loss improves speech discrimination in noise, even when results differ between the two ears. A study demonstrated that no preoperative factors predict CI benefit in either ear [17]. The choice between uni- or bilateral implantation, either simultaneous or successive, is thus individual, depending mainly on residual hearing in one ear and on the benefit obtained with the HA; it should take account of the fact that simultaneous bilateral implantation is followed by complete loss of speech comprehension during the activation and setting phase except in case of conserved hearing and bimodal stimulation: electric for high and acoustic for low frequencies, using an electro-acoustic implant. In case of residual hearing, even when HA performance is limited, CI provides benefit only after a few months, during which the patient will be in difficulty if implantation was bilateral, no longer having the benefit of the HA in the better ear. What then is the benefit of bilateral CI over CI + HA? A further study of performance in bilateral CI under the same conditions as in the present study would be useful to determine indications for sequential bilateral CI according to the benefit obtained during the transitional bimodal CI + HA phase.
• all the time? • just in some circumstances? • if so, which? If not, why did you stop? 2. Why do you wear your hearing aid? -
It improves my understanding of speech in silence Yes/No It improves my understanding of speech in noise Yes/No It improves my recognition of familiar sounds Yes/No It lets me hear on both sides and locate sounds better Yes/No It’s reassuring Yes/No It makes hearing more comfortable Yes/No Do you think wearing your hearing aid: ◦ made it easier to adapt to the cochlear implant? Yes/No ◦ made it take longer to progress with your cochlear implant? Yes/No ◦ complements your cochlear implant? Yes/No
3. Since you got your cochlear implant, do you reset your hearing aid regularly? Yes/No
5. Conclusion Technological progress in signal processing applied to cochlear implants has broadened the indications for CI. The present study, in adults with more or less rapidly progressive postlingual hearing loss, demonstrated the interest of performing CI as soon HA benefit diminishes, so as to conserve binaural hearing. Disclosure of interest The authors declare that they have no competing interest.
How often? Were you advised to? Yes/No 4. Do you think the cochlear implant has affected your hearing in the other ear? Yes/No - worsening it Yes/No - improving it Yes/No 5. Are you: right-handed? Yes/No
left-handed? Yes/No
Acknowledgments The authors thank Dr Evelyne Ferrary for finalizing the present paper.
Appendix 2. Questionnaire results for the 10 patients
Appendix 1. Pre-inclusion questionnaire (selection criterion) 1. Since you got your cochlear implant, have you still been wearing your hearing aid in the other ear? Yes/No If yes, do you wear it: Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002
G Model ANORL-494; No. of Pages 5
ARTICLE IN PRESS D. Bouccara et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2015) xxx–xxx
References [1] Traitement de la surdité par pose d’implants cochléaires ou d’implants du tronc cérébral. Rapport de la Haute Autorité de Santé; 2007 http://www.has-sante. fr/portail/upload/docs/application/pdf/rapport implants cochleaires.pdf. [2] Morera C, Manrique M, Ramos A, Garcia-Ibanez L, Cavalle L. Advantages of binaural hearing provided through bimodal stimulation via a cochlear implant and a conventional hearing aid: a 6 month comparative study. Acta Otolaryngol 2005;125(6):596–606. [3] Hamzavi J, Pok SM, Gstoettner W, Baumgartner WD. Speech perception with a cochlear implant used in conjuction with a hearing aid in the opposite ear. Int J Audiol 2004;43:61–5. [4] Ching TY, Incerti P, Hill M. Binaural benefits for adults who use hearing aids and cochlear implants in opposite ears. Ear Hear 2004;25:9–21. [5] Luntz M, Shpak T, Weiss H. Binaural-bimodal hearing: concomitant use of a unilateral cochlear implant and a controlateral hearing aid. Acta Otolaryngol 2005;125:863–9. [6] Firszt JB, Reeder RM, Skinner MW. Restoring hearing symmetry with two cochlear implants or one cochlear implant and a contralateral hearing aid. J Rehabil Res Dev 2008;45:749–67. [7] Ilg A, Bojanowicz M, Lesisnski- Schiedat A, Lenarz T, Bûchner A. Evaluation of the bimodal benefit in a large cohort of cochlear implant subjects using a contralateral hearing aid. Otol Neurotol 2014:23. [8] Shpak T, Most T, Luntz M. Fundamental frequency information for speech recognition via bimodal stimulation: cochlear implant in one ear and hearing aid in the other. Ear Hear 2014;35:97–109. [9] Hegarty L, Faulkner A. The perception of stress and intonation in children with cochlear implant and a hearing aid. Cochlear Implants Int 2013;14:S35–9, http://dx.doi.org/10.1179/1467010013.Z.
5
[10] Bartov T. Most T.song recognition by young children with cochlear implants: comparison between unilateral, bilateral and bimodal users. J Speech Lang Hear Res 2014;57:1929–41. [11] Fraysse B, Macías AR, Sterkers O, Burdo S, et al. Residual hearing conservation and electroacoustic stimulation with the nucleus 24 contour advance cochlear implant. Otol Neurotol 2006;27:624–33. [12] El Fata F, James CJ, Laborde ML, Fraysse B. How much residual hearing is ‘useful’ for music perception with cochlear implants? Audiol Neurootol 2009; 14(Suppl. 1):14–21. [13] Lazard D, Vincent C, Venail F, Van de Heyning P, Truy E, et al. Pre-, perand postoperative factors affecting performance of postlinguistically deaf adults using cochlear implants: a new conceptual model over time. PLoS One 2012;7(11):e48739, http://dx.doi.org/10.1371/journal.pone.0048739 [epub 2012 Nov]. [14] Neuman AC, Svirsky MA. Effect of hearing aid brandwidth on speech recognition performance of listeners using a cochlear implant and contralateral hearing aid (bimodal hearing). Ear Hear 2013;34:553–61. [15] Yehudai N, Shpak T, Most T, Luntz M. Functionnal status of hearing AIDS in bilateral-bimodal users. Otol Neurootol 2013;34:675–81. [16] Francart T, Mc Dermott H. Speech perception and localisation with SCORE bimodal: a loudness normalisation strategy for combined cochlear implant and hearing aid stimulation. PLoS One 2012;7(10):e45385, http://dx.doi.org/ 10.1371/journal.pone.0045385 [epub 2012 Oct 24]. [17] Mosnier I, Sterkers O, Bébéar JP, Godey B, et al. Speech performances and sound localization in complex noisy environment in bilaterally implanted adult patients. Audiol Neurootol 2009;14:106–14.
Please cite this article in press as: Bouccara D, et al. Benefit of contralateral hearing aid in adult cochlear implant bearers. European Annals of Otorhinolaryngology, Head and Neck diseases (2015), http://dx.doi.org/10.1016/j.anorl.2015.11.002