Song recognition by young children with cochlear implants: comparison between unilateral, bilateral, and bimodal users

Development and validation of BATUTA: a test to evaluate the musical perception of people with hearing impairment

PURPOSE

To describe the development and validation of a test, called BATUTA, that assesses the musical perception of people with hearing impairment that are hearing aid (HA) users. BATUTA is a computerized test with 35 subtests, divided into the rhythm, pitch, and timbre modules, and the participants must answer whether the sound samples and/or parts of the songs, presented in pairs, are the same or not.

METHODS

The BATUTA creation process consisted of four stages: test development, submission to the expert committee for content validation; pilot application with 51 normal hearing participants and retest to validate reliability. The process was based on several recommendations for the development and validation of musical assessment instruments. A deep investigation of the guidelines related to sound samples used, musical attributes evaluated, testing environment and the most appropriate response method was undertaken to ensure dependability.

RESULTS

The Content Validity Index (CVI) and expert agreement rates, when analyzed with the committee's recommendations, resulted in corrections and new audio recordings to ensure compliance to the test. The pilot test scores indicated internal consistency and the retest confirmed the reliability of BATUTA.

CONCLUSION

The results demonstrated the viability of BATUTA to assess the musical perception of people with hearing impairment that are HA users.

Pitch Accuracy of Vocal Singing in Deaf Children With Bimodal Hearing and Bilateral Cochlear Implants

OBJECTIVES

The purpose of the present study was to investigate the pitch accuracy of vocal singing in children with severe to profound hearing loss who use bilateral cochlear implants (CIs) or bimodal devices [CI at one ear and hearing aid (HA) at the other] in comparison to similarly-aged children with normal-hearing (NH).

DESIGN

The participants included four groups: (1) 26 children with NH, (2) 13 children with bimodal devices, (3) 31 children with bilateral CIs that were implanted sequentially, and (4) 10 children with bilateral CIs that were implanted simultaneously. All participants were aged between 7 and 11 years old. Each participant was recorded singing a self-chosen song that was familiar to him or her. The fundamental frequencies (F0) of individual sung notes were extracted and normalized to facilitate cross-subject comparisons. Pitch accuracy was quantified using four pitch-based metrics calculated with reference to the target music notes: mean note deviation, contour direction, mean interval deviation, and F0 variance ratio. A one-way ANOVA was used to compare listener-group difference on each pitch metric. A principal component analysis showed that the mean note deviation best accounted for pitch accuracy in vocal singing. A regression analysis examined potential predictors of CI children's singing proficiency using mean note deviation as the dependent variable and demographic and audiological factors as independent variables.

RESULTS

The results revealed significantly poorer performance on all four pitch-based metrics in the three groups of children with CIs in comparison to children with NH. No significant differences were found among the three CI groups. Among the children with CIs, variability in the vocal singing proficiency was large. Within the group of 13 bimodal users, the mean note deviation was significantly correlated with their unaided pure-tone average thresholds (r = 0.582, p = 0.037). The regression analysis for all children with CIs, however, revealed no significant demographic or audiological predictor for their vocal singing performance.

CONCLUSION

Vocal singing performance in children with bilateral CIs or bimodal devices is not significantly different from each other on a group level. Compared to children with NH, the pediatric bimodal and bilateral CI users, in general, demonstrated significant deficits in vocal singing ability. Demographic and audiological factors, known from previous studies to be associated with good speech and language development in prelingually-deafened children with CIs, were not associated with singing accuracy for these children.

Bimodal Fitting and Bilateral Cochlear Implants in Children With Significant Residual Hearing: The Impact of Asymmetry in Spatial Release of Masking on Localization

Purpose This study aimed to gain more insight into the primary auditory abilities of children with significant residual hearing in order to improve decision making when choosing between bimodal fitting or sequential bilateral cochlear implantation. Method Sound localization abilities, spatial release of masking, and fundamental frequency perception were tested. Nine children with bimodal fitting and seven children with sequential bilateral cochlear implants were included in the study. As a reference, 15 children with normal hearing and two children with simultaneous bilateral cochlear implants were included. Results On all outcome measures, the implanted children performed worse than the normal hearing children. For high-frequency localization, children with sequential bilateral cochlear implants performed significantly better than children with bimodal fitting. Compared to children with normal hearing, the left-right asymmetry in spatial release of masking was significant. When the implant was hindered by noise, bimodally fitted children obtained significantly lower spatial release of masking compared to when the hearing aid was hindered by noise. Overall, the larger the left-right asymmetry in spatial release of masking, the poorer the localization skills. No significant differences were found in fundamental frequency perception between the implant groups. Conclusions The data hint to an advantage of bilateral implantation over bimodal fitting. The extent of asymmetry in spatial release of masking is a promising tool for decision making when choosing whether to continue with the hearing aid or to provide a second cochlear implant in children with significant residual hearing.

Musical Perception Assessment of People With Hearing Impairment: A Systematic Review and Meta-Analysis

Purpose People with hearing impairment (HI) face numerous challenges that can be minimized with the use of hearing aids and cochlear implants. Despite technological advances in these assistive hearing devices, musical perception remains difficult for these people. Tests and protocols developed to assess the musical perception of this audience were the target of this systematic review, whose objective was to investigate how assessments of musical perception in people with HI are carried out. Method Searches for primary articles were carried out in the PubMed/MEDLINE, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature, and ASHAWire databases. Search results were managed using EndNote X9 software, and analysis was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Statement. Results The 16 cross-sectional included studies analyzed music perception data from people with HI compared to a control group of participants with normal hearing. Among these, four studies were selected to be included in a meta-analysis, performed with timbre and melody. Variability was observed in the tests and between the levels of auditory perception skills analyzed in relation to the components of music. With respect to the tests, sound stimuli generated by synthesizers were the most used stimuli; with the exception of timbre evaluation, the most frequent test environment was a booth with sound attenuation, and the average intensity for presenting sound stimuli was 70 dB SPL. The most evaluated sound component was pitch, followed by rhythm and timbre, with a pattern of responses based on adaptive and psychoacoustic methods. Conclusions The heterogeneity of the musical parameters and the auditory abilities evaluated by the tests is a fact that can compromise evidence found in this area of study. It is worth considering the quality of samples that were recorded with real musical instruments and digitized afterward, in comparison with synthesized samples that do not seem to accurately represent real instruments. The need to minimize semantic parallelism that involves the auditory skills and elements of music involved in the assessment of musical perception is highlighted.

Comparison of primary musicality development between children with cochlear implants and children with normal hearing

Background: It is beneficial for CI patients listen to music. However it is necessary to take steps to improve the musicality of CI patients.Objectives: The aims of the study were to evaluate the primary musicality of children with cochlear implants versus those with normal hearing.Material and methods: Children participating in this study were divided into two groups: the cochlear implant group (CI group) and the normal hearing group (NH group). The 'Musical Ears Evaluation Form for Professionals' was used to evaluate the subjects' primary musicality.Results: The scores for overall and the three subcategories of primary musicality in children with cochlear implants and in those with normal hearing also improved significantly over time (p < .05). The score for overall primary musicality was not significantly different between CI and NH groups in the same hearing age (p > .05). There were significant differences between the two groups in the same chronological age (p < .05).Conclusions and significance: The primary musicality in children with cochlear implants was not significantly different from normal hearing ones at the same hearing age. The primary musicality in children with cochlear implants was significantly lower than that of children with normal hearing at the same chronological age.

Effects of Low Frequency Residual Hearing on Music Perception and Psychoacoustic Abilities in Pediatric Cochlear Implant Recipients

Studies have demonstrated the benefits of low frequency residual hearing in music perception and for psychoacoustic abilities of adult cochlear implant (CI) users, but less is known about these effects in the pediatric group. Understanding the contribution of combined electric and acoustic stimulation in this group can help to gain a better perspective on decisions regarding bilateral implantation. We evaluated the performance of six unilaterally implanted children between 9 and 13 years of age with contralateral residual hearing using the Clinical Assessment of Music Perception (CAMP), spectral ripple discrimination (SRD), and temporal modulation transfer function (TMTF) tests and compared findings with previous research. Our study sample performed similarly to normal hearing subjects in pitch direction discrimination (0.81 semitones) and performed well above typical CI users in melody recognition (43.37%). The performance difference was less in timbre recognition (48.61%), SRD (1.47 ripple/octave), and TMTF for four modulation frequencies. These findings suggest that the combination of low frequency acoustic hearing with the broader frequency range of electric hearing can help to increase clinical CI benefit in pediatric users and decisions regarding second-side implantation should consider these factors.

Singing Proficiency of Members of a Choir Formed by Prelingually Deafened Children With Cochlear Implants

Purpose A group of 10 prelingually deafened children with cochlear implants (CIs) formed a choir and received 21 months of formal music training. The purpose of this study was to evaluate the singing proficiency of these children. Method The participants included all choir members (7 girls and 3 boys, mean age of 9.5 years old) who were unilateral CI users. Meanwhile, 8 age-matched children with normal hearing were recruited as controls and were trained on 1 song for 2 weeks. Individual singing samples without instrument accompaniment were recorded from all participants. The singing samples were subject to acoustic analysis in which the fundamental frequency (F0) of each note was extracted and the duration was measured. Five metrics were developed and computed to quantify the accuracy of their pitch and rhythm performance. The 5 metrics included (a) percent correct of F0 contour direction of adjacent notes, (b) mean deviation of the normalized F0 across the notes, (c) mean deviation of the pitch intervals, (d) mean deviation of adjacent note duration ratio, and (e) mean absolute deviation of note duration. Results The choir members with CIs demonstrated high accuracy in both pitch and tempo measures and performed on par with the children with normal hearing. Early start of music training after implantation and use of bimodal hearing contributed to the development of better music ability in these children with CIs. Conclusion These findings indicated that rigorous music training could facilitate high singing proficiency in prelingually deafened children with CIs.

Limiting asymmetric hearing improves benefits of bilateral hearing in children using cochlear implants

Neurodevelopmental changes occur with asymmetric hearing loss, limiting binaural/spatial hearing and putting children at risk for social and educational challenges. These deficits may be mitigated by providing bilateral hearing in children through auditory prostheses. Effects on speech perception and spatial hearing were measured in a large cohort of >450 children who were deaf and used bilateral cochlear implants or bimodal devices (one cochlear implant and a contralateral hearing aid). Results revealed an advantage of bilateral over unilateral device use but this advantage decreased as hearing in the two ears became increasingly asymmetric. Delayed implantation of an ear with severe to profound deafness allowed asymmetric hearing, creating aural preference for the better hearing ear. These findings indicate that bilateral input with the most appropriate device for each ear should be provided early and without delay during development.

The Benefits of Residual Hair Cell Function for Speech and Music Perception in Pediatric Bimodal Cochlear Implant Listeners

Objective

The aim of this study was to investigate the benefits of residual hair cell function for speech and music perception in bimodal pediatric Mandarin-speaking cochlear implant (CI) listeners.

Design

Speech and music performance was measured in 35 Mandarin-speaking pediatric CI users for unilateral (CI-only) and bimodal listening. Mandarin speech perception was measured for vowels, consonants, lexical tones, and sentences in quiet. Music perception was measured for melodic contour identification (MCI).

Results

Combined electric and acoustic hearing significantly improved MCI and Mandarin tone recognition performance, relative to CI-only performance. For MCI, performance was significantly better with bimodal listening for all semitone spacing conditions (p < 0.05 in all cases). For tone recognition, bimodal performance was significantly better only for tone 2 (rising; p < 0.05). There were no significant differences between CI-only and CI + HA for vowel, consonant, or sentence recognition.

Conclusions

The results suggest that combined electric and acoustic hearing can significantly improve perception of music and Mandarin tones in pediatric Mandarin-speaking CI patients. Music and lexical tone perception depends strongly on pitch perception, and the contralateral acoustic hearing coming from residual hair cell function provided pitch cues that are generally not well preserved in electric hearing.

Delayed access to bilateral input alters cortical organization in children with asymmetric hearing

Bilateral hearing in early development protects auditory cortices from reorganizing to prefer the better ear. Yet, such protection could be disrupted by mismatched bilateral input in children with asymmetric hearing who require electric stimulation of the auditory nerve from a cochlear implant in their deaf ear and amplified acoustic sound from a hearing aid in their better ear (bimodal hearing). Cortical responses to bimodal stimulation were measured by electroencephalography in 34 bimodal users and 16 age-matched peers with normal hearing, and compared with the same measures previously reported for 28 age-matched bilateral implant users. Both auditory cortices increasingly favoured the better ear with delay to implanting the deaf ear; the time course mirrored that occurring with delay to bilateral implantation in unilateral implant users. Preference for the implanted ear tended to occur with ongoing implant use when hearing was poor in the non-implanted ear. Speech perception deteriorated with longer deprivation and poorer access to high-frequencies. Thus, cortical preference develops in children with asymmetric hearing but can be avoided by early provision of balanced bimodal stimulation. Although electric and acoustic stimulation differ, these inputs can work sympathetically when used bilaterally given sufficient hearing in the non-implanted ear.

Music perception improves in children with bilateral cochlear implants or bimodal devices

The objectives of this study were to determine if music perception by pediatric cochlear implant users can be improved by (1) providing access to bilateral hearing through two cochlear implants or a cochlear implant and a contralateral hearing aid (bimodal users) and (2) any history of music training. The Montreal Battery of Evaluation of Musical Ability test was presented via soundfield to 26 bilateral cochlear implant users, 8 bimodal users and 16 children with normal hearing. Response accuracy and reaction time were recorded via an iPad application. Bilateral cochlear implant and bimodal users perceived musical characteristics less accurately and more slowly than children with normal hearing. Children who had music training were faster and more accurate, regardless of their hearing status. Reaction time on specific subtests decreased with age, years of musical training and, for implant users, better residual hearing. Despite effects of these factors on reaction time, bimodal and bilateral cochlear implant users' responses were less accurate than those of their normal hearing peers. This means children using bilateral cochlear implants and bimodal devices continue to experience challenges perceiving music that are related to hearing impairment and/or device limitations during development.

Bimodal Stimulation in Prelingually Deaf Children: Lessons from a Cross-sectional Survey

OBJECTIVE

(1) To survey the use of bimodal stimulation by prelingually deaf children receiving unilateral cochlear implantation and (2) to investigate demographic and audiologic factors explaining the use of bimodal stimulation.

STUDY DESIGN

Cross-sectional survey.

SETTING

Tertiary care institution.

SUBJECTS AND METHODS

The study included 44 unilaterally implanted prelingually deaf children from a single institution, with a minimum follow-up of 1 year. During routine follow-up visits, an examiner interviewed parents on their children's use of bimodal stimulation. At the same time, residual hearing and hearing aid gain in the contralateral ear were assessed.

RESULTS

Approximately half of patients (52%) used bimodal stimulation. On average, bimodal users showed better mean unaided and aided thresholds than nonbimodal users (P < .001). A mean 250- to 500-Hz unaided threshold ≤90 dB HL in the contralateral, nonimplanted ear was associated with a higher probability of bimodal use (P = .008). Parental satisfaction with the contralateral hearing aid was inversely correlated with mean 125- to 500-Hz and 1000- to 4000-Hz unaided thresholds (P < .001) and mean 250- to 500-Hz and 1000- to 4000-Hz aided thresholds (P < .001).

CONCLUSIONS

A mean 250- to 500-Hz unaided threshold ≤90 dB HL is associated with a higher probability of bimodal use by prelingually deaf children. Better residual hearing is associated with a higher degree of parental satisfaction with the contralateral hearing aid. This information could be useful to counsel parents of prelingually deaf children, when deciding between bimodal stimulation and simultaneous bilateral cochlear implantation.

Effects of Removing Low-Frequency Electric Information on Speech Perception With Bimodal Hearing

PURPOSE

The objective was to determine whether speech perception could be improved for bimodal listeners (those using a cochlear implant [CI] in one ear and hearing aid in the contralateral ear) by removing low-frequency information provided by the CI, thereby reducing acoustic-electric overlap.

METHOD

Subjects were adult CI subjects with at least 1 year of CI experience. Nine subjects were evaluated in the CI-only condition (control condition), and 26 subjects were evaluated in the bimodal condition. CIs were programmed with 4 experimental programs in which the low cutoff frequency (LCF) was progressively raised. Speech perception was evaluated using Consonant-Nucleus-Consonant words in quiet, AzBio sentences in background babble, and spondee words in background babble.

RESULTS

The CI-only group showed decreased speech perception in both quiet and noise as the LCF was raised. Bimodal subjects with better hearing in the hearing aid ear (< 60 dB HL at 250 and 500 Hz) performed best for words in quiet as the LCF was raised. In contrast, bimodal subjects with worse hearing (> 60 dB HL at 250 and 500 Hz) performed similarly to the CI-only group.

CONCLUSIONS

These findings suggest that reducing low-frequency overlap of the CI and contralateral hearing aid may improve performance in quiet for some bimodal listeners with better hearing.

What can we expect of normally-developing children implanted at a young age with respect to their auditory, linguistic and cognitive skills?

As a result of neonatal hearing screening and subsequent early cochlear implantation (CI) profoundly deaf children have access to important information to process auditory signals and master spoken language skills at a young age. Nevertheless, auditory, linguistic and cognitive outcome measures still reveal great variability in individual achievements: some children with CI(s) perform within normal limits, while others lag behind. Understanding the causes of this variation would allow clinicians to offer better prognoses to CI candidates and efficient follow-up and rehabilitation. This paper summarizes what we can expect of normally developing children with CI(s) with regard to spoken language, bilateral and binaural auditory perception, speech perception and cognitive skills. Predictive factors of performance and factors influencing variability are presented, as well as some novel data on cognitive functioning and speech perception in quiet and in noise. Subsequently, we discuss technical and non-technical issues which should be considered in the future in order to optimally guide the child with profound hearing difficulties. This article is part of a Special Issue entitled <Lasker Award>.