Comparison of electrophysiological parameters between perimodiolar and lateral wall electrodes in paediatric cochlear implant users.

PURPOSE: (1) To compare the in vivo impedances of electrical contacts of the Nucleus Contour Advance (CA) perimodiolar electrodes and the Nucleus Slim Straight (SS) lateral wall electrodes. (2) To compare the relation between the electrode contact impedances and the behavioural T-/C-levels for both types of electrodes. METHODS: Retrospective case review in two quaternary otologic referral centres was performed. Data on the impedance of the electrode contacts and the T-/C-levels have been collected from 70 consecutive paediatric CI patients. RESULTS: (1) SS electrodes show significantly higher impedance values of the contacts compared to the CA electrodes. This can be explained by differences in the active surface of the electrode contacts and is true for the whole electrode arrays. (2) There are significant negative correlations observed between the impedances of the electrode contacts and the behaviourally measured T-/C-levels. (3) The strength correlation between the electrode impedances and the behavioural T-/C-levels is significantly higher and the T-/C-level variability is lower for the perimodiolar CA electrodes than for the lateral wall SS electrodes. CONCLUSIONS: There exist significant differences in the contact impedance between different cochlear implant electrode arrays. These differences could influence the implant programming parameters and should be considered in any protocols related to automatic implant programming based on objective measures. The predictive value of the electrode impedances for the behavioural T-/C-levels is higher for the perimodiolar CA electrodes than for the lateral wall SS electrodes.

Malleostapedotomy with the self-fixing and articulated titanium piston.

OBJECTIVE: To analyze the results of malleostapedotomy performed by applying the self-fixing and articulated titanium piston according to Häusler. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS AND INTERVENTIONS: This study concerns a retrospective analysis of the results of malleostapedotomy with the use of a self-fixing articulated titanium piston in 16 ears of 16 consecutively treated patients between 2005 and 2009. The medical files were used for the acquisition of data on medical and surgical history and to obtain pre- and postoperative audiometry. Diagnosis and outcomes of mainly revision surgeries are presented and compared to the literature. MAIN OUTCOME MEASURES: Effect of (revision) malleostapedotomy by evaluating postoperative audiometry and air-bone gap closure. RESULTS: The postoperative air-bone gap closure was ≤ 10 dB in 9/16 (56%) ears and within ≤ 20 dB in 13/16 (81%) ears. The mean postoperative air-bone gap was 14.3 dB HL (0.5-2.0 kHz) and 17.3 dB HL (0.5-4.0 kHz). Postoperatively, there was no increase in bone conduction thresholds larger than 3 dB (0.5-2.0 kHz) and postoperative dizziness was absent or very limited and transient. CONCLUSIONS: The malleostapedotomy procedure has become surgically less demanding over time by the technical improvements present in the nowadays available pistons. The design of the self-fixing and articulated titanium piston used in the present group of patients allows a safe and straight-forward malleostapedotomy procedure. Present hearing outcomes match with results presented in the literature.

On the evaluation of a superpower sound processor for bone-anchored hearing.

OBJECTIVES: Performance of a superpower bone-anchored hearing aid (Baha), the Baha Cordelle from Cochlear Bone-Anchored Solutions (BCD1), was compared to its successor, the Baha 5 SuperPower (BCD2). DESIGN: A comparative study in which each patient served as its own control. SETTING: Tertiary clinic. PARTICIPANTS: Ten experienced BCD1 users with profound mixed hearing loss. For comparison, data from another study with 10 experienced users with a severe mixed hearing loss using a Cochlear Baha 5 power sound processor (BCD-P) were included. MAIN OUTCOME MEASURES: Speech reception thresholds in noise and APHAB and SSQ questionnaires. RESULTS: Speech reception thresholds for the digits-in-noise (DIN) test were significantly lower (P < 5%), that is more favourable, for BCD2 in the speech and noise frontal condition and in the speech frontal and noise contralateral condition than for BCD1. For the group with severe mixed loss fitted with BCD-P, the SRTs were not significantly different (P > 5%) from the BCD2 values. With the APHAB questionnaire scores were significantly lower, that is more favourable, for the ease of communication (P < 5%) and the background noise (P < 1%) domains for BCD2 than for BCD1. APHAB scores for the aversiveness of loud sounds domain were not significantly different for both devices (P > 5%). Scores for the speech and quality domains of the SSQ questionnaire were significantly higher, that is more favourable, for BCD2 than for BCD1. APHAB and SSQ scores for BCD-P were not significantly different from those for BCD2 (P > 5%). CONCLUSIONS: Data for BCD2 in profound mixed loss are similar to those for BCD-P and a severe mixed loss. Of 10 patients, 2 expressed a strong preference for BCD2 over BCD1, and 7 patients had a preference for BCD2 over BCD1. One patient preferred BCD1 because of its built-in telecoil facility.

Evaluation of an abutment-level superpower sound processor for bone-anchored hearing.

OBJECTIVES: Performance of an abutment-level superpower sound processor for bone-anchored hearing, the Ponto 3 SuperPower from Oticon Medical (BCD2), was compared to an earlier model from Oticon Medical (BCD1). DESIGN: A comparative study in which each patient serves as its own control. SETTING: Tertiary clinic. PARTICIPANTS: Eighteen experienced BCD1 users with profound mixed hearing loss. MAIN OUTCOME MEASURES: Speech reception thresholds in noise; APHAB and SSQ questionnaires. RESULTS: In a group of 18 patients with severe mixed hearing loss, the performance of a recently introduced bone conduction device (BCD2) is evaluated relative to that of an earlier model (BCD1). Speech reception thresholds for the sentence-in-noise test in the speech and noise frontal condition are not significantly different (P > .05) for BCD1 and BCD2. Speech reception thresholds for frontal speech and three identical noise sources are 1.7 dB lower for BCD2 than for BCD1 (P < .05). With the APHAB questionnaire, the score for background noise is significantly lower (P < .01), that is more favourable, for BCD2 than for BCD1 with an effect size of 0.91. The APHAB domain scores for ease-of-communication, reverberation and aversiveness of loud sounds are not significantly different for both devices (P > .05). Scores for the speech, spatial and quality of hearing domains of the SSQ questionnaire are significantly higher (P < .01), that is more favourable, for BCD2 than for BCD1 with effect sizes of 1.22, 0.71 and 1.05, respectively. Scores for the SSQ-factors "speech understanding," "spatial," "clarity, separation and identification" and "listening effort and concentration" were all significantly higher (P < .05) for BCD2 than for BCD1, with effect sizes of 1.28, 0.64, 0.98 and 0.78, respectively. On a proprietary questionnaire, 16 patients indicate a preference for BCD2 over BCD1 for conversations in a small group and two patients have no preference for either device. In a large group, one patient prefers BCD1, six patients have no preference, and eleven patients prefer BCD2. When listening to music, all patients prefer BCD2 over BCD1, with a strong preference for BCD2 for seven patients. When asked for an overall preference, all patients prefer BCD2 over BCD1, with nine patients strongly preferring BCD2. CONCLUSIONS: The lower speech reception thresholds in noise with BCD2 relative to BCD1 can be attributed to the "speech omni" directionality mode of BCD2. The combination of an improved directionality for primarily low-level inputs and a higher maximum force output, relevant for mid- and high-level inputs, results in a clear preference for BCD2 over BCD1.

CT findings of the temporal bone in CHARGE syndrome: aspects of importance in cochlear implant surgery.

To provide an overview of anomalies of the temporal bone in CHARGE syndrome relevant to cochlear implantation (CI), anatomical structures of the temporal bone and the respective genotypes were analysed. In this retrospective study, 42 CTs of the temporal bone of 42 patients with CHARGE syndrome were reviewed in consensus by two head-and-neck radiologists and two otological surgeons. Anatomical structures of the temporal bone were evaluated and correlated with genetic data. Abnormalities that might affect CI surgery were seen, such as a vascular structure, a petrosquamosal sinus (13 %), an underdeveloped mastoid (8 %) and an aberrant course of the facial nerve crossing the round window (9 %) and/or the promontory (18 %). The appearance of the inner ear varied widely: in 77 % of patients all semicircular canals were absent and the cochlea varied from normal to hypoplastic. A stenotic cochlear aperture was observed in 37 %. The middle ear was often affected with a stenotic round (14 %) or oval window (71 %). More anomalies were observed in patients with truncating mutations than with non-truncating mutations. Temporal bone findings in CHARGE syndrome vary widely. Vascular variants, aberrant route of the facial nerve, an underdeveloped mastoid, aplasia of the semicircular canals, and stenotic round window may complicate cochlear implantation.

Patients with Pendred syndrome: is cochlear implantation beneficial?

OBJECTIVE: To evaluate the benefit of cochlear implantation in patients with Pendred syndrome. DESIGN: Retrospective study. SETTING: Tertiary centre. PARTICIPANTS AND MAIN OUTCOME MEASURES: Speech perception was measured using a phonetically balanced word list at a sound pressure level of 65 dB. Post-operative phoneme scores at 12-month for adults and 36-month for children with Pendred syndrome were compared to scores of patients with an enlarged vestibular aqueduct (EVA) and a reference group with an unknown cause of hearing impairment. Quality of life was measured with the Nijmegen Cochlear Implant Questionnaire to evaluate the differences between pre- and post-implantation. RESULTS: The mean post-operative phoneme scores were as follows: in the Pendred group, 91% (n = 16; SD = 10) for children and 78% (n = 7; SD = 14) for adults; in the reference group, 79% (n = 59; SD = 20) for children and 73% (n = 193; SD = 18) for adults; and in the EVA group, 84% (n = 6; SD = 7) for children and 66% (n = 12; SD = 22) for adults. A significant difference in speech perception was found between the children of the Pendred group and the reference group of 11.4% (SE = 5.2; P = 0.031). Between the adults, a difference of 11.2% (SE = 6.7; P = 0.094) was found. The difference between the Pendred group and the EVA group was 5.7%(SE = 4.5; P = 0.22) for children and 9.9% (SE = 8.7; P = 0.28) for adults. A significant improvement post-implantation in four of the six subdomains of the quality of life questionnaire was found: basic sound perception (P = 0.002), advanced sound perception (P = 0.004), speech production (P = 0.018) and activity limitations (P = 0.018). The two not significant subdomains were self-esteem (P = 0.164) and social interaction (P = 0.107). CONCLUSIONS: After cochlear implantation, children with Pendred syndrome performed better than the reference group with respect to speech perception, however, adults performed similar. No significant differences were found between the Pendred and EVA group. Consequently, during pre-operative counselling, the two groups of patients may be considered comparable in terms of expected speech perception performance after cochlear implantation.

Stable long-term outcomes after cochlear implantation in subjects with TMPRSS3 associated hearing loss: a retrospective multicentre study.

BACKGROUND: The spiral ganglion hypothesis suggests that pathogenic variants in genes preferentially expressed in the spiral ganglion nerves (SGN), may lead to poor cochlear implant (CI) performance. It was long thought that TMPRSS3 was particularly expressed in the SGNs. However, this is not in line with recent reviews evaluating CI performance in subjects with TMPRSS3-associated sensorineural hearing loss (SNHL) reporting overall beneficial outcomes. These outcomes are, however, based on variable follow-up times of, in general, 1 year or less. Therefore, we aimed to 1. evaluate long-term outcomes after CI implantation of speech recognition in quiet in subjects with TMPRSS3-associated SNHL, and 2. test the spiral ganglion hypothesis using the TMPRSS3-group. METHODS: This retrospective, multicentre study evaluated long-term CI performance in a Dutch population with TMPRSS3-associated SNHL. The phoneme scores at 70 dB with CI in the TMPRSS3-group were compared to a control group of fully genotyped cochlear implant users with post-lingual SNHL without genes affecting the SGN, or severe anatomical inner ear malformations. CI-recipients with a phoneme score ≤ 70% at least 1-year post-implantation were considered poor performers and were evaluated in more detail. RESULTS: The TMPRSS3 group consisted of 29 subjects (N = 33 ears), and the control group of 62 subjects (N = 67 ears). For the TMPRSS3-group, we found an average phoneme score of 89% after 5 years, which remained stable up to 10 years post-implantation. At both 5 and 10-year follow-up, no difference was found in speech recognition in quiet between both groups (p = 0.830 and p = 0.987, respectively). Despite these overall adequate CI outcomes, six CI recipients had a phoneme score of ≤ 70% and were considered poor performers. The latter was observed in subjects with residual hearing post-implantation or older age at implantation. CONCLUSION: Subjects with TMPRSS3-associated SNHL have adequate and stable long-term outcomes after cochlear implantation, equal to the performance of genotyped patient with affected genes not expressed in the SGN. These findings are not in line with the spiral ganglion hypothesis. However, more recent studies showed that TMPRSS3 is mainly expressed in the hair cells with only limited SGN expression. Therefore, we cannot confirm nor refute the spiral ganglion hypothesis.

Lateralization of interaural level differences in children with bilateral cochlear implants.

OBJECTIVES: To investigate the perception of interaural level differences (ILDs) in children with bilateral cochlear implants (BiCIs) and compare them to normal hearing peers. As intracranial shifts in perception of ILDs might have an effect on localization, this was further investigated. METHODS: ILD responses on four different frequency bands (broadband, low-pass, mid-pass and high-pass) were measured in 9 children with BiCIs and 15 children with normal hearing. In the children with BiCIs, 7 of them were implanted sequentially and 2 of them simultaneously. The outcomes were compared with the outcomes from a previous study on advanced localization using the same stimuli as in the current study. The effect of chronological age, inter-implant delay and preoperative residual hearing were also taken into account. RESULTS: No significant differences in ILD responses between children with BiCIs and children with normal hearing were found. For broadband stimuli, children with sequential BiCIs showed a significant shift in their response towards the first implant. A significant correlation was found between inter-implant delay and shift in ILD response for the broadband and high-pass stimuli. The shift in ILD response had no effect on localization. CONCLUSION: Children with BiCIs are able to perceive ILD responses similar to those of normal hearing children. The inter-implant delay has a negative effect on the lateralization of the response towards the first implant side, indicative of deprivation of high-frequency sounds prior to receiving a second implant. This shift, however, is not associated with a shift in localization response.

Benefit of sequential bilateral cochlear implantation in children between 5 to 18 years old: A prospective cohort study.

OBJECTIVE: To determine the benefit of sequential cochlear implantation after a long inter-implantation interval in children with bilateral deafness receiving their second implant between 5 and 18 years of age. STUDY DESIGN: Prospective cohort-study. SETTING: Tertiary multicenter. PATIENTS: 85 children with bilateral deafness and unilateral implantation receiving a contralateral cochlear implant at the age of 5 to 18 years. METHOD: The primary outcomes were speech recognition in quiet and noise (CVC) scores. The secondary outcomes were language outcomes and subjective hearing abilities, all measured before and 12 months after sequential bilateral cochlear implantation. Medians of the paired data were compared using the Wilcoxon signed-rank test. Univariable linear regression analyses was used to analyze associations between variables and performance outcomes. RESULTS: A significant benefit was found for speech recognition in quiet (96% [89-98] vs 91% [85-96]; p < 0.01) and noise (65% [57-75] vs 54% [47-71]; p = 0.01) in the bilateral CI condition compared to unilateral (n = 75, excluded 10 non-users). No benefit was seen for language outcomes. The subjective sound quality score was statistically significant higher in bilateral compared to the unilateral CI condition. Pre-operative residual hearing level in the ear of the second implant, the inter-implant interval and age at time of second implantation was not significantly associated with performance scores. CONCLUSION: After 12 months of use, sequential bilateral cochlear implantation showed improved speech perception in quiet and noise and improved subjective sound quality outcomes in children despite a great inter-implantation interval (median of 8 years [range 1-16 years]).

Sound localization and binaural hearing in children with a hearing aid and a cochlear implant.

The aims of the study were to investigate whether sound localization acuity improved when children with 1 cochlear implant use a hearing aid in the contralateral ear (bimodal fitting), and whether this enabled them to benefit from a binaural masking level difference. Four different noise bursts were used as stimuli for a minimal audible angle localization test. On average, localization acuity remained poor with the cochlear implant alone, but also with bimodal fitting. A significant benefit of bimodal fitting was only shown when the most complicated stimulus with roved amplitude and spectrum was presented (minimal audible angle of 151 degrees with bimodal fitting vs. 175 degrees with cochlear implant alone). No significant binaural masking level difference was found between the cochlear implant alone and the bimodal condition.

Advantage of bimodal fitting in prosody perception for children using a cochlear implant and a hearing aid.

Cochlear implants are largely unable to encode voice pitch information, which hampers the perception of some prosodic cues, such as intonation. This study investigated whether children with a cochlear implant in one ear were better able to detect differences in intonation when a hearing aid was added in the other ear ("bimodal fitting"). Fourteen children with normal hearing and 19 children with bimodal fitting participated in two experiments. The first experiment assessed the just noticeable difference in F0, by presenting listeners with a naturally produced bisyllabic utterance with an artificially manipulated pitch accent. The second experiment assessed the ability to distinguish between questions and affirmations in Dutch words, again by using artificial manipulation of F0. For the implanted group, performance significantly improved in each experiment when the hearing aid was added. However, even with a hearing aid, the implanted group required exaggerated F0 excursions to perceive a pitch accent and to identify a question. These exaggerated excursions are close to the maximum excursions typically used by Dutch speakers. Nevertheless, the results of this study showed that compared to the implant only condition, bimodal fitting improved the perception of intonation.

Speech perception in congenitally, pre-lingually and post-lingually deaf children expressed in an equivalent hearing loss value.

OBJECTIVES: To investigate the speech perception performance of children with a cochlear implant (CI) after 3 and 4 years of follow-up and to study the influence of age at implantation, duration of deafness and communication mode on the variability in speech perception performance. STUDY DESIGN: A broad battery of speech perception tests was administered to 67 children with a CI. The results were reduced into one measure: the 'equivalent hearing loss (EHL)'. This outcome measure refers to the performance of a reference group of severely and profoundly hearing impaired children with conventional hearing aids. PARTICIPANTS: The population comprised 35 congenitally, 17 pre-lingually and 15 post-lingually deaf children implanted between 1989 and 1999. The population was homogeneous with respect to cognition, residual hearing and support at home as a result of conservative inclusion criteria. RESULTS: During the first 2 years after implantation, post-lingually deaf children showed the fastest rate of improvement in speech perception. After 3 years of implant use, the early implanted pre-lingually deaf children and congenitally deaf children implanted under the age of 6 years caught up with the post-lingually deaf children. Pre-lingually deaf children implanted after a relatively long-duration of deafness tended to show poorer performance than those with a shorter duration. Performance of congenitally deaf children implanted after the age of 6 years was poorer and progress was slower. In the congenitally deaf children, 36% of the variability in performance was explained by duration of deafness, whereas in the children with pre- and post-lingually acquired deafness, communication mode explained 69% of the variance. CONCLUSIONS: All children derived benefit from their CI for speech perception tasks, but performance varied greatly. Several children reached EHL levels around 70 dB; their speech perception was equal to that of a child with conventional hearing aids who has 70 dB HL. After early implantation, the levels of performance that were eventually achieved differed no more than 10 dB, irrespective of whether the onset of deafness was pre-lingual or postlingual. In congenitally deaf children, duration of deafness played a major role in speech perception performance, whereas in the children with pre-lingually and post-lingually acquired deafness together, mode of communication was a major factor.

[The practice guideline 'Otitis externa' (first revision) from the Dutch College of General Practitioners; a response from the perspective of otorhinolaryngology]. / De standaard 'Otitis externa' (eerste herziening) van het Nederlands Huisartsen Genootschap; reactie vanuit de kno-heelkunde.

The first revision of the practice guideline 'Otitis externa' from the Dutch College of General Practitioners describes diagnostic, therapeutic and preventive aspects of care and focuses mainly on the acute form of the disease. In comparison with the previous guideline, some modest but valuable improvements have been made with regard to diagnosis and medical treatment. For acute otitis externa, treatment with acid and corticosteroid eardrops is considered the treatment of choice, rather than treatment with acid eardrops only. The guideline clearly discusses indications for referral of patients with otitis externa to an otorhinolaryngologist. Hypersensitivity and more severe pathology should be excluded in persistent cases. For chronic otitis externa, an otorhinolaryngologist can provide surgical treatment with a good chance of success and a low recurrence rate.

Objective and Subjective Measures of Simultaneous vs Sequential Bilateral Cochlear Implants in Adults: A Randomized Clinical Trial.

Importance: To date, no randomized clinical trial on the comparison between simultaneous and sequential bilateral cochlear implants (BiCIs) has been performed. Objective: To investigate the hearing capabilities and the self-reported benefits of simultaneous BiCIs compared with those of sequential BiCIs. Design, Setting, and Participants: A multicenter randomized clinical trial was conducted between January 12, 2010, and September 2, 2012, at 5 tertiary referral centers among 40 participants eligible for BiCIs. Main inclusion criteria were postlingual severe to profound hearing loss, age 18 to 70 years, and a maximum duration of 10 years without hearing aid use in both ears. Data analysis was conducted from May 24 to June 12, 2016. Interventions: The simultaneous BiCI group received 2 cochlear implants during 1 surgical procedure. The sequential BiCI group received 2 cochlear implants with an interval of 2 years between implants. Main Outcomes and Measures: First, the results 1 year after receiving simultaneous BiCIs were compared with the results 1 year after receiving sequential BiCIs. Second, the results of 3 years of follow-up for both groups were compared separately. The primary outcome measure was speech intelligibility in noise from straight ahead. Secondary outcome measures were speech intelligibility in noise from spatially separated sources, speech intelligibility in silence, localization capabilities, and self-reported benefits assessed with various hearing and quality of life questionnaires. Results: Nineteen participants were randomized to receive simultaneous BiCIs (11 women and 8 men; median age, 52 years [interquartile range, 36-63 years]), and another 19 participants were randomized to undergo sequential BiCIs (8 women and 11 men; median age, 54 years [interquartile range, 43-64 years]). Three patients did not receive a second cochlear implant and were unavailable for follow-up. Comparable results were found 1 year after simultaneous or sequential BiCIs for speech intelligibility in noise from straight ahead (difference, 0.9 dB [95% CI, -3.1 to 4.4 dB]) and all secondary outcome measures except for localization with a 30° angle between loudspeakers (difference, -10% [95% CI, -20.1% to 0.0%]). In the sequential BiCI group, all participants performed significantly better after the BiCIs on speech intelligibility in noise from spatially separated sources and on all localization tests, which was consistent with most of the participants' self-reported hearing capabilities. Speech intelligibility-in-noise results improved in the simultaneous BiCI group up to 3 years following the BiCIs. Conclusions and Relevance: This study shows comparable objective and subjective hearing results 1 year after receiving simultaneous BiCIs and sequential BiCIs with an interval of 2 years between implants. It also shows a significant benefit of sequential BiCIs over a unilateral cochlear implant. Until 3 years after receiving simultaneous BiCIs, speech intelligibility in noise significantly improved compared with previous years. Trial Registration: trialregister.nl Identifier: NTR1722.

A database system for the registration of complications and failures in cochlear implant surgery applied to over 1000 implantations performed in Nijmegen, The Netherlands.

OBJECTIVE: To create a system for the uniform registration and classification of complications and failures in cochlear implant surgery, and apply it to all the patients who underwent implantation in our clinic. METHOD: The definition of a medical complication was established, and data for all cochlear implantations performed between 1987 and 2012 were entered into a custom-made database system. RESULTS: One or more medical complications were registered in 19.0 per cent of 1003 cochlear implantations. The incidence of 'hard failure' was 2.3 per cent. Findings revealed a decrease in device failures over the years; the rate of medical complications remained constant. CONCLUSION: Our database system, which is available free of charge, enables fast and accurate data entry. There were a relatively high number of (minor) complications in our series, but comparison with the relevant literature is difficult. This emphasises the need for a uniform definition of 'complication' as it relates to cochlear implant surgery, and an appropriate classification system for such complications.

Two siblings with progressive, fluctuating hearing loss after head trauma, treated with cochlear implantation.

OBJECTIVE: Description of two siblings with unexplained, progressive, perceptive hearing loss after head trauma. DESIGN: Case report. SUBJECTS: Two siblings aged six and eight years old with bilateral, intermittent but progressive hearing loss. RESULTS: These patients had a c.1172G>A (p.Ser391Asn) mutation in the SLC26A4 gene, which has not previously been reported and which caused Pendred or enlarged vestibular aqueduct syndrome. The diagnosis was based on the perceptive hearing loss, computed tomography findings and mutation analysis. The patients were each fitted with a cochlear implant because of their severe, progressive, perceptive hearing loss with deep fluctuations. The results were good. CONCLUSION: Further testing for the presence of an enlarged vestibular aqueduct is recommended when children present with sudden progression in perceptive hearing loss, whether or not in combination with head trauma. Cochlear implantation is indicated in patients with persistent, progressive hearing loss that leads to deafness. Implantation can be undertaken successfully despite cochlear hypoplasia.

Bilateral versus unilateral cochlear implantation in young children.

OBJECTIVES: To compare the preverbal communication skills of two groups of young implanted children: those with unilateral implantation and those with bilateral implantation. MATERIAL AND METHODS: The study assessed 69 children: 42 unilaterally and 27 bilaterally implanted with age at implantation less than 3 years. The preverbal skills of these children were measured before and 1 year after implantation, using Tait Video Analysis that has been found able to predict later speech outcomes in young implanted children. RESULTS: Before implantation there was no significant difference between the unilateral group and the bilateral group. There was still no difference at 12 months following implantation where vocal autonomy is concerned, but a strongly significant difference between the groups for vocal turn-taking and non-looking vocal turns, the bilateral group outperforming the unilateral group. Regarding gestural turn-taking and gestural autonomy, there was a strongly significant difference between the two groups at the 12 month interval, and also a difference before implantation for gestural autonomy, the unilateral group having the higher scores. Multiple regression of non-looking vocal turns revealed that 1 year following implantation, bilateral implantation contributed to 51% of the variance (p<0.0001), after controlling for the influence of age at implantation and length of deafness which did not reach statistical significance. CONCLUSIONS: Profoundly deaf bilaterally implanted children are significantly more likely to use vocalisation to communicate, and to use audition when interacting vocally with an adult, compared with unilaterally implanted children. These results are independent of age at implantation and length of deafness.