Contralateral Hearing Aid Research Articles

International survey of bimodal hearing and bilateral cochlear implant service provision for adults

Objectives As cochlear implant (CI) criteria widen, more candidates with usable residual hearing are being considered for a CI. Unlike children, adults mostly receive only one implant. The aim of this survey was to determine bimodal-hearing and bilateral CI service provision for adults around the world. This survey offers the backdrop against which future clinical practice and service delivery can be considered. Methods CI professionals from across the world were invited to participate in an international multicentre survey. The online questionnaire was circulated to CI professionals in 75 countries. There were 64 respondents, representing 25 countries across five world regions. Results In this sample, adult CI users most had unilateral CI (74.5%) and only 25.5% were bilateral CI users. Some 54% of unilateral CI users used a hearing aid (HA) in the non-implanted ear. Funding for a second implant or HA was not well supported for adult unilateral CI users, and there was no clear practice guidance for fitting and maintaining the contralateral HA in most regions. Conclusions CI professionals recognised the value of fitting contralateral HAs at CI services, with audiology departments and private HA dispensers playing an ongoing role in general maintenance and support.

Vocal Emotion Perception in Children Using Cochlear Implant.

The significance of emotional prosody in social communication is well-established, yet research on emotion perception among cochlear implant (CI) users is less extensive. This study aims to explore vocal emotion perception in children using CI and bimodal hearing devices and compare them with their normal hearing (NH) peers. The study involved children aged 4-10 years with unilateral CI and contralateral hearing aid (HA), matched with NH peers by gender and listening age. Children were selected using snowball sampling for the CI group and purposive sampling for the NH group. Vocal emotion perception was assessed for semantically neutral sentences in "happy," "sad," and "angry" emotions using a 3 alternate forced choice test. The NH group demonstrated significantly superior emotion perception (P=.002) compared to the CI group. Both groups accurately identified the "happy" emotion. However, the NH group had higher scores for the "angry" emotion compared to the "sad" emotion, while the CI group showed better scores for "sad" than "angry" emotion. Bimodal hearing devices improved recognition of "sad"and "angry" emotions, with a decrease in confusion percentages. The unbiased hit (Hu) value provided more substantial insight than the hit score. Bimodal hearing devices enhance the perception of "sad" and "angry" vocal emotions compared to using a CI alone, likely due to the HA providing the temporal fine structure cues, thereby better representing fundamental frequency variations. Children with unilateral CI benefit significantly in the perception of emotions by using a HA in the contralateral ear, aiding in better socio-emotional development.

Integrated bimodal fitting and binaural streaming technology outcomes for unilateral cochlear implant users

Objective Adults typically receive only one cochlear implant (CI) due to cost constraints, with a contralateral hearing aid recommended when there is aidable hearing. Standard hearing aids differ from a CI in terms of processing strategy and function as a separate entity, requiring the user to integrate the disparate signals. Integrated bimodal technology has recently been introduced to address this challenge. The aim of the study was to investigate the performance of unilateral CI users with and without an integrated bimodal fitting and determine whether binaural streaming technology offers additional benefit. Study sample Twenty-six CI users using integrated bimodal technology. Design Repeated measures where outcomes and user experience were assessed using a functional test battery more representative of real life listening (speech perception in noise tests, localisation test, tracking test) and the speech, spatial and qualities-of-hearing scale (SSQ). Results Bimodal outcomes were significantly better than for CI alone. Speech perception in noise improvements ranged from 1.4 dB to 3.5 dB depending on the location of speech and noise. The localisation and tracking tests, and the SSQ also showed significant improvements. Binaural streaming offered additional improvement (1.2 dB to 6.1 dB on the different speech tests). Conclusions Integrated bimodal and binaural streaming technology improved the performance of unilateral CI users.

Quality of Life With Cochlear Implantation Using the CIQOL-35 at a Tertiary Urban Medical Center: Our Experience.

Assessment of quality-of-life (QOL) outcomes after cochlear implantation (CI) using the Cochlear Implant Quality of Life-35 questionnaire (CIQOL-35). Retrospective cohort. Single-institution tertiary care center. Patients 18 years and older who have undergone CI and CIQOL-35 survey. Implementing CIQOL-35 from 2019 to 2022 to measure change in QOL after CI. Statistical analysis included nonparametric, univariate, and multivariate analyses. Significance was set at 0.05. Differences in QOL among CI patients in each of the CIQOL-35 domains. Ninety-three patients (40 female, 53 male) aged 20 to 93 years (median 70 years) turned in 164 QOL surveys (68 preactivation, 96 postactivation). Postactivation median QOL was 5 to 15 points higher across all domains ( p < 0.001). QOL score distributions among unilateral CI only, bilateral CI, and unilateral CI with contralateral hearing aid users were not statistically different ( p > 0.05). Multivariate analysis identified that male sex ( β = -2.0; 95% confidence interval, -3.9 to -0.1) was a negative predictor for environment scores and not being married ( β = 2.0; 95% confidence interval, 0.02 to 4.0) was a positive predictor for entertainment scores. Median follow-up time was 13 months post-CI (interquartile range [IQR], 7.1-21.5 months). CI patients experienced improved QOL postactivation among all QOL domains, whereas specific CI use pattern in regard to unilateral, bilateral, or bimodal did not affect QOL. Multivariate analysis identified marital status and sex as possible QOL predictors.

CROS or hearing aid? Selecting the ideal solution for unilateral CI patients with limited aidable hearing in the contralateral ear.

A hearing aid or a contralateral routing of signal device are options for unilateral cochlear implant listeners with limited hearing in the unimplanted ear; however, it is uncertain which device provides greater benefit beyond unilateral listening alone. Eighteen unilateral cochlear implant listeners participated in this prospective, within-participants, repeated measures study. Participants were tested with the cochlear implant alone, cochlear implant + hearing aid, and cochlear implant + contralateral routing of signal device configurations with a one-month take-home period between each in-person visit. Audiograms, speech perception in noise, and lateralization were evaluated. Subjective feedback was obtained via questionnaires. Marked improvement in speech in noise and non-implanted ear lateralization accuracy were observed with the addition of a contralateral hearing aid. There were no significant differences in speech recognition between listening configurations. However, the chronic device use questionnaires and the final device selection showed a clear preference for the hearing aid in spatial awareness and communication domains. Individuals with limited hearing in their unimplanted ears demonstrate significant improvement with the addition of a contralateral device. Subjective questionnaires somewhat contrast with clinic-based outcome measures, highlighting the delicate decision-making process involved in clinically advising one device or another to maximize communication benefits.

Localization of Low- and High-Frequency Sounds in Cochlear Implant Recipients Using a Contralateral Hearing Aid.

The ability to localize sounds is partly recovered in patients using a cochlear implant (CI) in one ear and a hearing aid (HA) on the contralateral side. Binaural processing seems effective at least to some extent, despite the difference between electric and acoustic stimulation in each ear. To obtain further insights into the mechanisms of binaural hearing in these listeners, localization of low- and high-frequency sounds was tested. The study used a within-subject design, where participants were tasked with localizing sound sources in the horizontal plane. The experiment was conducted in an anechoic chamber, where an array of seven loudspeakers was mounted along the 24 azimuthal angle span from -90° to +90°. Stimuli were applied with different frequencies: broadband noise and high- and low-frequency noise. Ten CI recipients participated in the study. All had an asymmetric hearing loss with a CI in the poorer ear and an HA on the contralateral side. Accuracy of sound localization in terms of angular error and percentage of correct localization scores. The median angular error was 40° in bimodal conditions for both broadband noise and high-frequency noise stimuli. The angular error increased to 47° for low-frequency noise stimuli. In the unilaterally aided condition with an HA, only a median angular error of 78° was observed. Irrespective of the frequency composition of the stimuli, this group of bimodal listeners showed some ability to localize sounds. Angular errors were larger than those reported in the literature for bilateral CI users or single-sided deaf listeners with a CI. In the unilateral listening condition with HA, only localization of sounds was not possible for most subjects.

Validation of the Norwegian Version of the Speech, Spatial and Qualities of Hearing Scale (SSQ)

Introduction: The main objective of the study was to validate the Norwegian translation of the Speech, Spatial and Qualities of Hearing Scale (SSQ) and investigate the SSQ disability profiles in a cochlear implant (CI) user population. Methods: The study involved 152 adult CI users. The mean age at implantation was 55 (standard deviation [SD] = 16), and the mean CI experience was 5 years (SD = 4.8). The cohort was split into three groups depending on the hearing modality: bilateral CIs (BCIs), a unilateral CI (UCI), and bimodal (CI plus contralateral hearing aid; HCI). The SSQ disability profiles of each group were compared with those observed in similar studies using the English version and other translations of the SSQ. Standard values, internal consistency, sensitivity, and floor and ceiling effects were investigated, and the missing-response rates to specific questions were calculated. Relationships to speech perception were measured using monosyllabic word scores and the Norwegian Hearing in Noise Test scores. Results: In the BCI group, the average scores were around 5.0 for the speech and spatial sections and 7.0 for the qualities section (SD ∼2). The average scores of the UCI and HCI groups were about one point lower than those of the BCI group. The SSQ disability profiles were comparable to the profiles in similar studies. The slopes of the linear regression lines measuring the relationships between the SSQ speech and monosyllabic word scores were 0.8 per 10% increase in the monosyllabic word score for the BCI group (explaining 35% of the variation) and 0.4 for the UCI and HCI groups (explaining 22–23% of the variation). Conclusion: The Norwegian version of the SSQ measures hearing disability similar to the original English version, and the internal consistency is good. Differences in the recipients’ pre-implantation variables could explain some variations we observed in the SSQ responses, and such predictors should be investigated. Data aggregation will be possible using the SSQ as a routine clinical assessment in global CI populations. Moreover, pre-implantation variables should be systematically registered so that they can be used in mixed-effects models.

Objective discrimination of bimodal speech using frequency following responses

Bimodal hearing, in which a contralateral hearing aid is combined with a cochlear implant (CI), provides greater speech recognition benefits than using a CI alone. Factors predicting individual bimodal patient success are not fully understood. Previous studies have shown that bimodal benefits may be driven by a patient's ability to extract fundamental frequency (f0) and/or temporal fine structure cues (e.g., F1). Both of these features may be represented in frequency following responses (FFR) to bimodal speech. Thus, the goals of this study were to: 1) parametrically examine neural encoding of f0 and F1 in simulated bimodal speech conditions; 2) examine objective discrimination of FFRs to bimodal speech conditions using machine learning; 3) explore whether FFRs are predictive of perceptual bimodal benefit. Three vowels (/ε/, /i/, and /ʊ/) with identical f0 were manipulated by a vocoder (right ear) and low-pass filters (left ear) to create five bimodal simulations for evoking FFRs: Vocoder-only, Vocoder +125 Hz, Vocoder +250 Hz, Vocoder +500 Hz, and Vocoder +750 Hz. Perceptual performance on the BKB-SIN test was also measured using the same five configurations. Results suggested that neural representation of f0 and F1 FFR components were enhanced with increasing acoustic bandwidth in the simulated “non-implanted” ear. As spectral differences between vowels emerged in the FFRs with increased acoustic bandwidth, FFRs were more accurately classified and discriminated using a machine learning algorithm. Enhancement of f0 and F1 neural encoding with increasing bandwidth were collectively predictive of perceptual bimodal benefit on a speech-in-noise task. Given these results, FFR may be a useful tool to objectively assess individual variability in bimodal hearing.

Longitudinal outcomes for educational placement and quality of life in a prospectively recruited multinational cohort of children with cochlear implants

The aim of this study was to report on the educational placement, quality of life and speech reception changes in a prospectively recruited group of children after they received a cochlear implant (CI). Data was collected on 1085 CI recipients of as part of a prospective, longitudinal, observational, international, multi-centre, paediatric registry, initiated by Cochlear Ltd (Sydney, NSW, Australia). Outcome data from children (≤10 years old) implanted in routine practice was voluntarily entered into a central, externally hosted, e-platform. Collection occurred prior to initial device activation (baseline) and at six monthly follow-up intervals up to 24 months and then at 3 years post activation. Clinician reported baseline and follow up questionnaires and Categories of Auditory Performance version II (CAP-II) outcomes were collated. Self-reported evaluation forms and patient information were provided by the parent/caregiver/patient via the implant recipient baseline and follow up, Children Using Hearing Implants Quality of Life (CuHIQoL) and Speech Spatial Qualities (SSQ-P) Parents Version questionnaires. Children were mainly bilaterally profoundly deaf, unilaterally implanted and used a contralateral hearing aid. Prior to implant 60% used signing or total communication as their main mode of communication. Mean age at implant was 3.2±2.2 years (range 0-10 years). At baseline 8.6% were in mainstream education with no additional support and 82% had not yet entered school. After three years of implant use, 52% had entered mainstream education with no additional support and 38% had not yet entered school. In the sub-group of 141 children who were implanted at or after three years of age and were thus old enough to be in mainstream school at the three-year follow up, an even higher proportion (73%) were in mainstream education with no support. Quality of life scores for the child improved statistically significantly post implant compared to baseline and continued to improve significantly at each interval up to 3 years (p<0.001). Parental expectation scores reduced statistically significantly from baseline compared to all intervals (p<0.028) and then increased significantly at 3 years compared to all post baseline follow-up intervals (p<0.006). The impact on family life was reduced post implant compared to baseline and continued to reduce between annual intervals (p<0.001). At three years post follow up median CAP II scores were 7 (IQR 6-7) and mean SSQ-P scores were 6.8 (SD1.9) 6.0 (SD1.9) and 7.4 (SD 2.3) for speech spatial and qualities scales respectively. SSQ-P and CAP II scores improved statistically and clinically significantly compared to baseline by one year post implantation. CAP II scores continued to improve at each test interval up to three years post implant. Speech and Qualities scores improved significantly between years 1 and 2 (p<0.001), but only the Speech scores improved significantly between years 2 and 3 (p=0.004). Mainstream educational placement was achievable for most of the children, including those implanted at an older age. Quality of life for the child and the wider family improved. Future research could focus on the impact of mainstream school placement on children's academic progress, including measures of academic attainment and social functioning.

Children using a unilateral cochlear implant and contralateral hearing aid: bimodal hearing outcomes when one ear is outside the UK (NICE 2009) audiological criteria for cochlear implantation – a single site case–control study

IntroductionIn the new revised National Institute for Health & Care Excellence (NICE, TA566, 2019) guidelines for cochlear implantation (CI) have clearly stipulated that the hearing loss must be bilateral. Prior...

Contralateral hearing aid use in adult cochlear implant recipients: retrospective analysis of auditory outcomes

Objective To investigate retrospectively the frequency of usage of bimodal stimulation among cochlear implant (CI) users, as well its clinical benefit relative to unilateral use. Design All subjects had been monitored with the clinical Minimal Outcome Measurements test battery. Study samples 103 adults with bilateral postlingual profound sensorineural hearing loss and unilateral CI use were extracted from the local database. These were divided into two groups: those who only used a CI and those who used bimodal stimulation. Results The preoperative contralateral residual hearing in the bimodal group was significantly better than that of the CI-only group. In both groups, speech perception in quiet and in noise improved after CI, with no significant difference between postoperative unimodal conditions. For the bimodal group, an additional significant improvement was found for the bimodal condition compared to the unimodal. Conclusion Given the observed auditory benefit of bimodal stimulation in comparison to unimodal stimulation and given the finding that degree of residual hearing is not correlated with bimodal benefits, it is recommended to encourage CI recipients to continue contralateral HA use after CI. As a result of expanding CI criteria worldwide, the population of bimodal users is expected to grow in the near future.

Preliminary evaluation of computer-assisted home training for French cochlear implant recipients.

For French cochlear implant (CI) recipients, in-person clinical auditory rehabilitation is typically provided during the first few years post-implantation. However, this is often inconvenient, it requires substantial time resources and can be problematic when appointments are unavailable. In response, we developed a computer-based home training software ("French AngelSound™") for French CI recipients. We recently conducted a pilot study to evaluate the newly developed French AngelSound™ in 15 CI recipients (5 unilateral, 5 bilateral, 5 bimodal). Outcome measures included phoneme recognition in quiet and sentence recognition in noise. Unilateral CI users were tested with the CI alone. Bilateral CI users were tested with each CI ear alone to determine the poorer ear to be trained, as well as with both ears (binaural performance). Bimodal CI users were tested with the CI ear alone, and with the contralateral hearing aid (binaural performance). Participants trained at home over a one-month period (10 hours total). Phonemic contrast training was used; the level of difficulty ranged from phoneme discrimination in quiet to phoneme identification in multi-talker babble. Unilateral and bimodal CI users trained with the CI alone; bilateral CI users trained with the poorer ear alone. Outcomes were measured before training (pre-training), immediately after training was completed (post-training), and one month after training was stopped (follow-up). For all participants, post-training CI-only vowel and consonant recognition scores significantly improved after phoneme training with the CI ear alone. For bilateral and bimodal CI users, binaural vowel and consonant recognition scores also significantly improved after training with a single CI ear. Follow-up measures showed that training benefits were largely retained. These preliminary data suggest that the phonemic contrast training in French AngelSound™ may significantly benefit French CI recipients and may complement clinical auditory rehabilitation, especially when in-person visits are not possible.

Development of Auditory and Speech Language Performance Following Bimodal Cochlear Implantation in a Pre-lingual Late Implantee: A Case Report

Objective - To describe the performance in terms of auditory and speech-language development in a late implanted patient with bimodal cochlear implantation.Study Design - Prospective Case study.Subject – A girl with congenital bilateral sensorineural hearing loss with speech and language delay having left ear profound SNHL and right ear severe to profound SNHL.Intervention – Unilateral cochlear implant with neubio BOLD CI system done at the age of 15 years following auditory verbal therapy.Main Outcome Measures – “Meaningful auditory integration scale (MAIS)”, “Revised categories of auditory performance (Revised CAP)”, “Speech intelligibility rating (SIR)”, “Child using hearing devices QOL (cuHDQOL)”, 3D- language acquisition test (3D- LAT), “Parent evaluation aural/oral performance of children (PEACH)” and “Teacher evaluation aural/oral performance of children (TEACH)” is used to assess the outcomes of the cochlear implantation.Results – “Revised CAP,” “SIR,” “MAIS,” “cuHDQOL,” “3D-LAT”, “PEACH,” and “TEACH” scores showed improvement in the implanted teenager over time.Conclusion - The findings represent the evidence for better outcomes of late cochlear implanted patients with bimodal stimulation. It may also provide convincing results about the benefits with the use of Neubio BOLD Cochlear Implant system with a contralateral hearing aid.

Integration of fundamental frequency and voice-onset-time to voicing categorization: Listeners with normal hearing and bimodal hearing configurations.

This study investigates the integration of word-initial fundamental frequency (F0) and voice-onset-time (VOT) in stop voicing categorization for adult listeners with normal hearing (NH) and unilateral cochlear implant (CI) recipients utilizing a bimodal hearing configuration [CI + contralateral hearing aid (HA)]. Categorization was assessed for ten adults with NH and ten adult bimodal listeners, using synthesized consonant stimuli interpolating between /ba/ and /pa/ exemplars with five-step VOT and F0 conditions. All participants demonstrated the expected categorization pattern by reporting /ba/ for shorter VOTs and /pa/ for longer VOTs, with NH listeners showing more use of VOT as a voicing cue than CI listeners in general. When VOT becomes ambiguous between voiced and voiceless stops, NH users make more use of F0 as a cue to voicing than CI listeners, and CI listeners showed greater utilization of initial F0 during voicing identification in their bimodal (CI + HA) condition than in the CI-alone condition. The results demonstrate the adjunctive benefit of acoustic hearing from the non-implanted ear for listening conditions involving spectrotemporally complex stimuli. This finding may lead to the development of a clinically feasible perceptual weighting task that could inform clinicians about bimodal efficacy and the risk-benefit profile associated with bilateral CI recommendation.

Production of Tone 2 in disyllabic words in Mandarin Chinese speaking children aged 3-5 with a cochlear implant and a contralateral hearing aid

ABSTRACT To investigate Mandarin Tone 2 production of disyllabic words of prelingually deafened children with a cochlear implant (CI) and a contralateral hearing aid (HA) and to evaluate the relationship between their demographic variables and tone-production ability. Thirty prelingually Mandarin-speaking preschoolers with CI+HA and 30 age-matched normal-hearing (NH) children participated in the study. Fourteen disyllabic words were recorded from each child. A total of 840 tokens (14 × 60) were then used in tone-perception tests in which four speech therapists participated. The production of T2-related disyllabic words of the bimodal group was significantly worse than that of the NH group, as reflected in the overall accuracy (88.57% ± 16.31% vs 99.29% ± 21.79%, p < 0.05), the accuracy of T1+T2 (93.33% vs 100%), the accuracy of T2+T1 (66.67 ± 37.91% vs 98.33 ± 9.13%), and the accuracy of T2+T4 (78.33 ± 33.95% vs 100%). In addition, the bimodal group showed significantly inferior production accuracy of T2+T1 than T2+T2 and T3+T2, p < 0.05. Both bimodal age and implantation age were significantly negatively correlated with the overall production accuracy, p < 0.05. For the error patterns, bimodal participants experienced more errors when T2 was in the first position of the tone combination, and T2 was most likely to be mispronounced as T1 and T3. Bimodal patients aged 3–5 have T2-related disyllabic lexical tone production defects, and their performances are related to tone combination, implantation age, and bimodal age.

Objective discrimination of bimodal speech using the frequency following response: A machine learning approach

Bimodal hearing, which combines a cochlear implant (CI) with a contralateral hearing aid, provides significant speech recognition benefits relative to a monaural CI. Factors predicting bimodal benefit remain poorly understood but may involve extracting fundamental frequency and/or formant information from the non-implanted ear. This study investigated whether neural responses (frequency following responses, FFRs) to simulated bimodal signals can be (1) accurately classified using machine learning and (2) used to predict perceptual bimodal benefit. We hypothesized that FFR classification accuracy would improve with increasing acoustic bandwidth due to greater fundamental and formant frequency access. Three vowels (/e/, /i/, and /ʊ/) with identical fundamental frequencies were manipulated to create five bimodal simulations (vocoder in right ear, lowpass filtered in left ear): Vocoder-only, Vocoder +125 Hz, Vocoder +250 Hz, Vocoder +500 Hz, and Vocoder +750 Hz. Perceptual performance on the BKB-SIN test was also measured using the same five configurations. FFR classification accuracy improved with increasing bimodal acoustic bandwidth. Furthermore, FFR bimodal benefit predicted behavioral bimodal benefit. These results indicate that the FFR may be useful in objectively verifying and tuning bimodal configurations.

Bilateral cochlear implants or bimodal hearing: A comparison of quality of life

Current literature suggests that bimodal users (i.e., individuals using a cochlear implant—CI—and a contralateral hearing aid) may report better outcomes in some listening situations (e.g., pitch perception and music appreciation) than bilateral CI users; however, several studies report conflicting results. Currently, there is no widely accepted criterion for bilateral simultaneous or sequential CI candidacy in adults, and clinicians typically rely on the patient’s experience to determine whether bilateral or bimodal hearing is best for that individual. Therefore, in this study we compare responses from twenty-four bilateral and bimodal users on the Cochlear Implant Quality of Life (CIQOL) questionnaire. Results demonstrated that bilateral CI users report better scores for the emotional, environmental, social, listening effort, and global scales than bimodal users. No significant difference in age, speech recognition abilities, and duration of hearing loss between the two groups were observed; however, the two groups did differ on their duration of CI use, such that the bimodal users had less experience listening with their CIs than the bilateral CI users. These findings do not replicate previous in-lab results, which demonstrate a bimodal user advantage and stresses the need to further explore the self-reported benefits of bimodal versus bilateral CI hearing.

Outcome of language therapy in bimodal-fit children versus unilateral cochlear implant children in bilateral sensorineural hearing impairment: a case-control study

BackgroundTreating hearing-impaired children aims not only to improve their hearing but also to enhance language acquisition capability. In our community, the CI usually performed on one side because of financial issues at least for a period of time. Consequently, the brain may neglect the unfitted ear. Contralateral hearing aid is an alternative solution when bilateral CI is unavailable. Our purpose is to evaluate the language outcome in bimodal-fit children who using cochlear implant (CI) and contralateral hearing aid (HA) compared to children using unilateral cochlear implant only.ResultsIn this case-control study, 15 children who are using binaural-bimodal stimulation by unilateral CI and contralateral HA and 15 children using monaural cochlear implant received auditory training and language therapy. All participants have been assigned randomly from the Phoniatrics and Audiology clinics. Filtering of patients was made to get the two groups matched regarding age, sex, family motivation, age of implantation, and age of hearing impairment. Evaluation and language therapy were performed in the Phoniatrics clinic. Language progress in each group was compared over different time-points. Also, it was compared between the two groups in each time-point. Both groups revealed significant language improvement over time with intensive auditory training and language therapy. In addition, the bimodal-fit children showed better language and speech outcomes than the unilateral CI children in receptive semantics, expressive semantics, word class, mean length of utterance, and speech intelligibility. The differences were significant with P-values 0.047, 0.034, 0.03, 0.016, and 0.028, respectively, after 9 months of rehabilitation.ConclusionBimodal-fit children showed better improvement in language than the unilateral CI group. The contralateral hearing aid may be complementary to the unilateral cochlear implant by covering wider speech frequency range. Also, it prevents auditory deprivation and enables binaural hearing with positive impact on language outcome.

The role of child- and auditory-related factors on speech and language indices among cochlear-implanted children

Objectives Numerous factors may affect the spoken language of children with a cochlear implant (CI). The present study is aimed to detect some of the possible predictors of speech and language outcomes among Persian-speaking cochlear-implanted children Materials and methods A total of 211 pre-lingual deaf children who received a cochlear implant were entered in this cross-sectional study. The Persian version of Speech Intelligibility Measurement Test and Test of Language Development (TOLD: P3) were employed to determine speech and language scores. Eight probable predictors (variables) were divided into three groups: child-related, auditory-related, and environmental factors. Results The use of contra-lateral hearing aid only enhanced the speech intelligibility (p = .029); while having a background of speech therapy prior to CI raised the participants’ language scores (p ≤ .041). Other factors predicted all speech and language indicators (p ≤ .025). Conclusion Speech-language therapists (SLTs) should inform parents about the positive or negative consequences of each pre-CI factor in post-operative speech and language outcomes.

Acoustic bandwidth effects on envelope following responses to simulated bimodal hearing

Bimodal hearing, which combines a cochlear implant (CI) with a contralateral hearing aid, provides significant speech recognition benefits in quiet and noise. These benefits have also been observed in normal-hearing listeners using vocoder-based CI simulation combined with low-pass filtered speech, even with acoustic bandwidths as narrow as 125–250 Hz. However, it is challenging to measure the optimal acoustic amplification with difficult-to-test populations, such as young children and adults with disabilities. The frequency following response (FFR) offers a potential solution to this problem, as it objectively quantifies subcortical phase-locking to speech features. Recently, FFR fundamental frequency amplitude in the non-implanted ear was found to be well-correlated with bimodal benefit in CI patients. The present study aimed to parametrically examine acoustic bandwidth effects (125, 250, 500, and 750 Hz) on speech evoked FFRs using simulated bimodal stimuli. We hypothesized that FFRenv amplitudes would increase as bandwidth increases up to 750 Hz and the minimal acoustic bandwidth needed to derive FFR bimodal benefit is less than 250 Hz.