Music Recognition, Music Listening, and Word Recognition by Deaf Children with Cochlear Implants

Effect of Sound Coding Strategies on Music Perception with a Cochlear Implant

The goal of this study was to evaluate the music perception of cochlear implantees with two different sound processing strategies. Methods: Twenty-one patients with unilateral or bilateral cochlear implants (Oticon Medical®) were included. A music trial evaluated emotions (sad versus happy based on tempo and/or minor versus major modes) with three tests of increasing difficulty. This was followed by a test evaluating the perception of musical dissonances (marked out of 10). A novel sound processing strategy reducing spectral distortions (CrystalisXDP, Oticon Medical) was compared to the standard strategy (main peak interleaved sampling). Each strategy was used one week before the music trial. Results: Total music score was higher with CrystalisXDP than with the standard strategy. Nine patients (21%) categorized music above the random level (>5) on test 3 only based on mode with either of the strategies. In this group, CrystalisXDP improved the performances. For dissonance detection, 17 patients (40%) scored above random level with either of the strategies. In this group, CrystalisXDP did not improve the performances. Conclusions: CrystalisXDP, which enhances spectral cues, seemed to improve the categorization of happy versus sad music. Spectral cues could participate in musical emotions in cochlear implantees and improve the quality of musical perception.

Music perception and training for pediatric cochlear implant users

INTRODUCTION

Cochlear implants (CIs) are biomedical devices that restore sound perception for people with severe-to-profound sensorineural hearing loss. Most postlingually deafened CI users are able to achieve excellent speech recognition in quiet environments. However, current CI sound processors remain limited in their ability to deliver fine spectrotemporal information, making it difficult for CI users to perceive complex sounds. Limited access to complex acoustic cues such as music, environmental sounds, lexical tones, and voice emotion may have significant ramifications on quality of life, social development, and community interactions.

AREAS COVERED

The purpose of this review article is to summarize the literature on CIs and music perception, with an emphasis on music training in pediatric CI recipients. The findings have implications on our understanding of noninvasive, accessible methods for improving auditory processing and may help advance our ability to improve sound quality and performance for implantees.

EXPERT OPINION

Music training, particularly in the pediatric population, may be able to continue to enhance auditory processing even after performance plateaus. The effects of these training programs appear generalizable to non-trained musical tasks, speech prosody and, emotion perception. Future studies should employ rigorous control groups involving a non-musical acoustic intervention, standardized auditory stimuli, and the provision of feedback.

Implicit Processing of Pitch in Postlingually Deafened Cochlear Implant Users

Cochlear implant (CI) users can only access limited pitch information through their device, which hinders music appreciation. Poor music perception may not only be due to CI technical limitations; lack of training or negative attitudes toward the electric sound might also contribute to it. Our study investigated with an implicit (indirect) investigation method whether poorly transmitted pitch information, presented as musical chords, can activate listeners’ knowledge about musical structures acquired prior to deafness. Seven postlingually deafened adult CI users participated in a musical priming paradigm investigating pitch processing without explicit judgments. Sequences made of eight sung-chords that ended on either a musically related (expected) target chord or a less-related (less-expected) target chord were presented. The use of a priming task based on linguistic features allowed CI patients to perform fast judgments on target chords in the sung music. If listeners’ musical knowledge is activated and allows for tonal expectations (as in normal-hearing listeners), faster response times were expected for related targets than less-related targets. However, if the pitch percept is too different and does not activate musical knowledge acquired prior to deafness, storing pitch information in a short-term memory buffer predicts the opposite pattern. If transmitted pitch information is too poor, no difference in response times should be observed. Results showed that CI patients were able to perform the linguistic task on the sung chords, but correct response times indicated sensory priming, with faster response times observed for the less-related targets: CI patients processed at least some of the pitch information of the musical sequences, which was stored in an auditory short-term memory and influenced chord processing. This finding suggests that the signal transmitted via electric hearing led to a pitch percept that was too different from that based on acoustic hearing, so that it did not automatically activate listeners’ previously acquired musical structure knowledge. However, the transmitted signal seems sufficiently informative to lead to sensory priming. These findings are encouraging for the development of pitch-related training programs for CI patients, despite the current technological limitations of the CI coding.

Benefits of Music Training for Perception of Emotional Speech Prosody in Deaf Children With Cochlear Implants

Objectives:

Children who use cochlear implants (CIs) have characteristic pitch processing deficits leading to impairments in music perception and in understanding emotional intention in spoken language. Music training for normal-hearing children has previously been shown to benefit perception of emotional prosody. The purpose of the present study was to assess whether deaf children who use CIs obtain similar benefits from music training. We hypothesized that music training would lead to gains in auditory processing and that these gains would transfer to emotional speech prosody perception.

Design:

Study participants were 18 child CI users (ages 6 to 15). Participants received either 6 months of music training (i.e., individualized piano lessons) or 6 months of visual art training (i.e., individualized painting lessons). Measures of music perception and emotional speech prosody perception were obtained pre-, mid-, and post-training. The Montreal Battery for Evaluation of Musical Abilities was used to measure five different aspects of music perception (scale, contour, interval, rhythm, and incidental memory). The emotional speech prosody task required participants to identify the emotional intention of a semantically neutral sentence under audio-only and audiovisual conditions.

Results:

Music training led to improved performance on tasks requiring the discrimination of melodic contour and rhythm, as well as incidental memory for melodies. These improvements were predominantly found from mid- to post-training. Critically, music training also improved emotional speech prosody perception. Music training was most advantageous in audio-only conditions. Art training did not lead to the same improvements.

Conclusions:

Music training can lead to improvements in perception of music and emotional speech prosody, and thus may be an effective supplementary technique for supporting auditory rehabilitation following cochlear implantation.

Alpha EEG Frontal Asymmetries during Audiovisual Perception in Cochlear Implant Users

Objectives: The aim of the present study is to investigate the variations of the electroencephalographic (EEG) alpha rhythm in order to measure the appreciation of bilateral and unilateral young cochlear implant users during the observation of a musical cartoon. The cartoon has been modified for the generation of three experimental conditions: one with the original audio, another one with a distorted sound and, finally, a mute version.

Methods: The EEG data have been recorded during the observation of the cartoons in the three experimental conditions. The frontal alpha EEG imbalance has been calculated as a measure of motivation and pleasantness to be compared across experimental populations and conditions.

Results: The EEG frontal imbalance of the alpha rhythm showed significant variations during the perception of the different cartoons. In particular, the pattern of activation of normal-hearing children is very similar to the one elicited by the bilateral implanted patients. On the other hand, results related to the unilateral subjects do not present significant variations of the imbalance index across the three cartoons.

Conclusion: The presented results suggest that the unilateral patients could not appreciate the difference in the audio format as well as bilaterally implanted and normal hearing subjects. The frontal alpha EEG imbalance is a useful tool to detect the differences in the appreciation of audiovisual stimuli in cochlear implant patients.

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.

Adult Cochlear Implant Users Are Able to Discriminate Basic Tonal Features in Musical Patterns: Evidence From Event-related Potentials

OBJECTIVE

Measurement of electrophysiological correlates of discrimination abilities of basic musical features in pre- and postlingually deafened adult cochlear implant (CI) users.

STUDY DESIGN

Electroencephalographic study. Comparison between CI users and matched normal hearing controls.

PATIENTS

Thirty-six hearing impaired adults using a cochlear implant for 4 to 15 months. Profound hearing impairment was acquired either before (N = 12) or after language acquisition (N = 17). Seven patients suffered from a single-sided deafness.

METHODS

Presentation of auditory stimuli consisting of musical four tone standard patterns and deviant patterns varying with regard to tone pitch, timbre, intensity, and rhythm of two different degrees. Analysis of electrophysiological, event-related mismatch responses.

RESULTS

Cochlear implant users elicited significant mismatch responses on most deviant features. Comparison to controls revealed significantly smaller mismatch negativity amplitudes. Except for one parameter (pitch) there were no reliable differences between pre- and postlingually deafened CI users.

CONCLUSION

Despite a highly reduced complexity of neural auditory stimulation by the cochlear implant device in comparison to the physiological cochlear input, CI users exhibit cortical discriminatory responses to relatively subtle basic tonal alterations.

Dance Movements Enhance Song Learning in Deaf Children with Cochlear Implants

Music perception of cochlear implants (CI) users is constrained by the absence of salient musical pitch cues crucial for melody identification, but is made possible by timing cues that are largely preserved by current devices. While musical timing cues, including beats and rhythms, are a potential route to music learning, it is not known what extent they are perceptible to CI users in complex sound scenes, especially when pitch and timbral features can co-occur and obscure these musical features. The task at hand, then, becomes one of optimizing the available timing cues for young CI users by exploring ways that they might be perceived and encoded simultaneously across multiple modalities. Accordingly, we examined whether training tasks that engage active music listening through dance might enhance the song identification skills of deaf children with CIs. Nine CI children learned new songs in two training conditions: (a) listening only (auditory learning), and (2) listening and dancing (auditory-motor learning). We examined children's ability to identify original song excerpts, as well as mistuned, and piano versions from a closed-set task. While CI children were less accurate than their normal hearing peers, they showed greater song identification accuracies in versions that preserved the original instrumental beats following learning that engaged active listening with dance. The observed performance advantage is further qualified by a medium effect size, indicating that the gains afforded by auditory-motor learning are practically meaningful. Furthermore, kinematic analyses of body movements showed that CI children synchronized to temporal structures in music in a manner that was comparable to normal hearing age-matched peers. Our findings are the first to indicate that input from CI devices enables good auditory-motor integration of timing cues in child CI users for the purposes of listening and dancing to music. Beyond the heightened arousal from active engagement with music, our findings indicate that a more robust representation or memory of musical timing features was made possible by multimodal processing. Methods that encourage CI children to entrain, or track musical timing with body movements, may be particularly effective in consolidating musical knowledge than methods that engage listening only.

Jumpstarting auditory learning in children with cochlear implants through music experiences

Musical experiences are a valuable part of the lives of children with cochlear implants (CIs). In addition to the pleasure, relationships and emotional outlet provided by music, it serves to enhance or 'jumpstart' other auditory and cognitive skills that are critical for development and learning throughout the lifespan. Musicians have been shown to be 'better listeners' than non-musicians with regard to how they perceive and process sound. A heuristic model of music therapy is reviewed, including six modulating factors that may account for the auditory advantages demonstrated by those who participate in music therapy. The integral approach to music therapy is described along with the hybrid approach to pediatric language intervention. These approaches share the characteristics of placing high value on ecologically valid therapy experiences, i.e., engaging in 'real' music and 'real' communication. Music and language intervention techniques used by the authors are presented. It has been documented that children with CIs consistently have lower music perception scores than do their peers with normal hearing (NH). On the one hand, this finding matters a great deal because it provides parameters for setting reasonable expectations and highlights the work still required to improve signal processing with the devices so that they more accurately transmit music to CI listeners. On the other hand, the finding might not matter much if we assume that music, even in its less-than-optimal state, functions for CI children, as for NH children, as a developmental jumpstarter, a language-learning tool, a cognitive enricher, a motivator, and an attention enhancer.

Experience Changes How Emotion in Music Is Judged: Evidence from Children Listening with Bilateral Cochlear Implants, Bimodal Devices, and Normal Hearing

Children using unilateral cochlear implants abnormally rely on tempo rather than mode cues to distinguish whether a musical piece is happy or sad. This led us to question how this judgment is affected by the type of experience in early auditory development. We hypothesized that judgments of the emotional content of music would vary by the type and duration of access to sound in early life due to deafness, altered perception of musical cues through new ways of using auditory prostheses bilaterally, and formal music training during childhood. Seventy-five participants completed the Montreal Emotion Identification Test. Thirty-three had normal hearing (aged 6.6 to 40.0 years) and 42 children had hearing loss and used bilateral auditory prostheses (31 bilaterally implanted and 11 unilaterally implanted with contralateral hearing aid use). Reaction time and accuracy were measured. Accurate judgment of emotion in music was achieved across ages and musical experience. Musical training accentuated the reliance on mode cues which developed with age in the normal hearing group. Degrading pitch cues through cochlear implant-mediated hearing induced greater reliance on tempo cues, but mode cues grew in salience when at least partial acoustic information was available through some residual hearing in the contralateral ear. Finally, when pitch cues were experimentally distorted to represent cochlear implant hearing, individuals with normal hearing (including those with musical training) switched to an abnormal dependence on tempo cues. The data indicate that, in a western culture, access to acoustic hearing in early life promotes a preference for mode rather than tempo cues which is enhanced by musical training. The challenge to these preferred strategies during cochlear implant hearing (simulated and real), regardless of musical training, suggests that access to pitch cues for children with hearing loss must be improved by preservation of residual hearing and improvements in cochlear implant technology.

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

PURPOSE

To examine song identification by preschoolers with normal hearing (NH) versus preschoolers with cochlear implants (CIs).

METHOD

Participants included 45 children ages 3;8-7;3 (years;months): 12 with NH and 33 with CIs, including 10 with unilateral CI, 14 with bilateral CIs, and 9 bimodal users (CI-HA) with unilateral CI and contralateral hearing aid. Preschoolers were asked to identify children's songs presented via 5 versions: (a) full (lyrics sung with piano accompaniment); (b) a cappella (only lyrics); (c) melodic (matching main melodic contour); (d) tonal (only pitch information); and (e) rhythmic (only song's rhythm).

RESULTS

The NH group surpassed all CI groups at identifying songs via melodic and tonal versions, but no significant differences emerged between the NH group and any CI group via full, a cappella, or rhythmic versions. Among the CI groups, no significant differences emerged via melodic or rhythmic versions, but bimodal users performed significantly better than bilateral users via the tonal version. Chronological age and duration of CI use correlated significantly with identification via the rhythmic version.

CONCLUSION

Bimodal users showed an advantage in identifying songs in the tonal version through use of complementary information.

Children's identification of familiar songs from pitch and timing cues

The goal of the present study was to ascertain whether children with normal hearing and prelingually deaf children with cochlear implants could use pitch or timing cues alone or in combination to identify familiar songs. Children 4–7 years of age were required to identify the theme songs of familiar TV shows in a simple task with excerpts that preserved (1) the relative pitch and timing cues of the melody but not the original instrumentation, (2) the timing cues only (rhythm, meter, and tempo), and (3) the relative pitch cues only (pitch contour and intervals). Children with normal hearing performed at high levels and comparably across the three conditions. The performance of child implant users was well above chance levels when both pitch and timing cues were available, marginally above chance with timing cues only, and at chance with pitch cues only. This is the first demonstration that children can identify familiar songs from monotonic versions—timing cues but no pitch cues—and from isochronous versions—pitch cues but no timing cues. The study also indicates that, in the context of a very simple task, young implant users readily identify songs from melodic versions that preserve pitch and timing cues.

Neuroelectrical imaging study of music perception by children with unilateral and bilateral cochlear implants

OBJECTIVE

To investigate by means of non-invasive neuroelectrical imaging the differences in the perceived pleasantness of music between children with cochlear implants (CI) and normal-hearing (NH) children.

METHODS

5 NH children and 5 children who received a sequential bilateral CI were assessed by means of High-Resolution EEG with Source Reconstruction as they watched a musical cartoon. Implanted children were tested before and after the second implant. For each subject the scalp Power Spectral Density was calculated in order to investigate the EEG alpha asymmetry.

RESULTS

The scalp topographic distribution of the EEG power spectrum in the alpha band was different in children using one CI as compared to NH children (see figure). With two CIs the cortical activation pattern changed significantly, becoming more similar to the one observed in NH children.

CONCLUSIONS

The findings support the hypothesis that bilateral CI users have a closer-to-normal perception of the pleasantness of music than unilaterally implanted children.

Neuroelectrical imaging investigation of cortical activity during listening to music in prelingually deaf children with cochlear implants

OBJECTIVE

To date, no objective measure of the pleasantness of music perception by children with cochlear implants has been reported. The EEG alpha asymmetries of pre-frontal cortex activation are known to relate to emotional/affective engagement in a perceived stimulus. More specifically, according to the "withdrawal/approach" model, an unbalanced de-synchronization of the alpha activity in the left prefrontal cortex has been associated with a positive affective state/approach toward a stimulus, and an unbalanced de-synchronization of the same activity in the right prefrontal cortex with a negative affective state/withdrawal from a stimulus. In the present study, High-Resolution EEG with Source Reconstruction was used to compare the music-induced alpha asymmetries of the prefrontal cortex in a group of prelingually deaf implanted children and in a control group of normal-hearing children.

METHODS

Six normal-hearing and six age-matched deaf children using a unilateral cochlear implants underwent High-Resolution EEG recordings as they were listening to a musical cartoon. Musical stimuli were delivered in three versions: Normal, Distort (reverse audio flow) and Mute. The EEG alpha rhythm asymmetry was analyzed: Power Spectral Density was calculated for each Region of Interest, together with a right-left imbalance index. A map of cortical activation was then reconstructed on a realistic cortical model.

RESULTS

Asymmetries of EEG alpha rhythm in the prefrontal cortices were observed in both groups. In the normal-hearing children, the asymmetries were consistent with the withdrawal/approach model, whereas in cochlear implant users they were not. Moreover, in implanted children a different pattern of alpha asymmetries in extrafrontal cortical areas was noticed as compared to normal-hearing subjects.

CONCLUSIONS

The peculiar pattern of alpha asymmetries in implanted children's prefrontal cortex in response to musical stimuli suggests an inability by these subjects to discriminate normal from dissonant music and to appreciate the pleasantness of normal music. High-Resolution EEG may prove to be a promising tool for objectively measuring prefrontal cortex alpha asymmetries in child cochlear implant users.

Accurate guitar tuning by cochlear implant musicians

Modern cochlear implant (CI) users understand speech but find difficulty in music appreciation due to poor pitch perception. Still, some deaf musicians continue to perform with their CI. Here we show unexpected results that CI musicians can reliably tune a guitar by CI alone and, under controlled conditions, match simultaneously presented tones to <0.5 Hz. One subject had normal contralateral hearing and produced more accurate tuning with CI than his normal ear. To understand these counterintuitive findings, we presented tones sequentially and found that tuning error was larger at ∼30 Hz for both subjects. A third subject, a non-musician CI user with normal contralateral hearing, showed similar trends in performance between CI and normal hearing ears but with less precision. This difference, along with electric analysis, showed that accurate tuning was achieved by listening to beats rather than discriminating pitch, effectively turning a spectral task into a temporal discrimination task.

The Music Experiences and Attitudes Of A First Cohort of Prelingually-Deaf Adolescents and Young Adults CI Recipients

The purpose of this study was to examine the musical engagement (participation and attitude) of pediatric CI recipients who were implanted during early childhood and who have reached age 15 or older. A questionnaire was administered to a group of 31 prelingually deaf CI users who receive annual follow up services and assessment in a clinical research center. The questionnaire was used to examine involvement in and attitudes toward music in school, the community, and in the home; social affiliation (hearing, Deaf, both) and mode of communication (oral, manual, both) were also examined. Despite the technical limitations of cochlear implants in transmitting pitch, melody, and tone quality, over two thirds of this sample described music as being important or very important in their lives. A high level of past and present familial involvement in music was associated with higher levels of current involvement and importance of music in the lives of adolescent and young adult CI users. Comparisons were noted with data from prior studies of persons with hearing loss who were non-CI users.

Investigation on the music perception skills of Italian children with cochlear implants

OBJECTIVE

To compare the music perception skills of a group of Italian-speaking children with cochlear implants to those of a group of normal hearing children; to analyze possible correlations between implanted children's musical skills and their demographics, clinical characteristics, phonological perception, and speech recognition and production abilities.

METHODS

18 implanted children aged 5-12 years and a reference group of 23 normal-hearing subjects with typical language development were enrolled. Both groups received a melody identification test and a song (i.e. original version) identification test. The implanted children also received a test battery aimed at assessing speech recognition, speech production and phoneme discrimination.

RESULTS

The implanted children scored significantly worse than the normal hearing subjects in both musical tests. In the cochlear implant group, phoneme discrimination abilities were significantly correlated with both melody and song identification skills, and length of device use was significantly correlated with song identification skills.

CONCLUSIONS

Experience with device use and phonological perception had a moderate-to-strong correlation to implanted children's music perception abilities. In the light of these findings, it is reasonable to assume that a rehabilitation program specifically aimed at improving phonological perception could help pediatric cochlear implant recipients better understand the basic elements of music; moreover, a training aimed at improving the comprehension of the spectral elements of music could enhance implanted children's phonological skills.

The music perception abilities of prelingually deaf children with cochlear implants

OBJECTIVE

To investigate the music perception abilities of prelingually deaf children with cochlear implants, in comparison to a group of normal-hearing children, and to consider the factors that contribute to music perception.

METHODS

The music perception abilities of 39 prelingually deaf children with unilateral cochlear implants were compared to the abilities of 39 normal hearing children. To assess the music listening abilities, the MuSIC perception test was adopted. The influence of the child's age, age at implantation, device experience and type of sound-processing strategy on the music perception were evaluated. The effects of auditory performance, nonverbal intellectual abilities, as well as the child's additional musical education on music perception were also considered.

RESULTS

Children with cochlear implants and normal hearing children performed significantly differently with respect to rhythm discrimination (55% vs. 82%, p<0.001), instrument identification (57% vs. 88%, p<0.001) and emotion rating (p=0.022). However we found no significant difference in terms of melody discrimination and dissonance rating between the two groups. There was a positive correlation between auditory performance and melody discrimination (r=0.27; p=0.031), between auditory performance and instrument identification (r=0.20; p=0.059) and between the child's grade (mark) in school music classes and melody discrimination (r=0.34; p=0.030). In children with cochlear implant only, the music perception ability assessed by the emotion rating test was negatively correlated to the child's age (r(S)=-0.38; p=0.001), age at implantation (r(S)=-0.34; p=0.032), and device experience (r(S)=-0.38; p=0.019). The child's grade in school music classes showed a positive correlation to music perception abilities assessed by rhythm discrimination test (r(S)=0.46; p<0.001), melody discrimination test (r(S)=0.28; p=0.018), and instrument identification test (r(S)=0.23; p=0.05).

CONCLUSIONS

As expected, there was a marked difference in the music perception abilities of prelingually deaf children with cochlear implants in comparison to the group of normal hearing children, but not for all the tests of music perception. Additional multi-centre studies, including a larger number of participants and a broader spectrum of music subtests, considering as many as possible of the factors that may contribute to music perception, seem reasonable.

Developing a music programme for preschool children with cochlear implants

Although music perception is especially challenging for cochlear implant (CI) users, young CI users' musical perception abilities are improved by participation in structured musical activities.

OBJECTIVES

To design, implement, evaluate, and publish a music training programme with a monitoring tool for preschool CI users, for use in family-centred habilitation programmes.

METHODS

We devised a programme of musical activities, Musical EARS®, and a curriculum-related hierarchical Evaluation Form to represent performance. The programme included sections on singing; recognizing songs, tunes, and timbre; and responding appropriately to music and rhythm. It was implemented over 18 months at Ilkses Rehabilitation Centre, with 25 paediatric MED-EL CI users split into three groups of varying age, duration of CI use, and ability.

RESULTS

Mean total scores increased significantly for all groups. Scores increased unevenly across subscales. Participation in and enjoyment of musical activities increased for both children and parents. Significant correlations were found between scores and length of CI use.

DISCUSSION

The training programme effectively enriches child CI users' musical experience. To varying degrees, children learned to perform the Musical EARS® activities. The study allowed us to validate the lesson content and the hierarchical nature of the Evaluation Form. We conclude that prelingually deafened CI users should be systematically involved in musical activities to help them acquire skills acquired more easily by hearing peers.

Melodic contour identification and music perception by cochlear implant users

Research and outcomes with cochlear implants (CIs) have revealed a dichotomy in the cues necessary for speech and music recognition. CI devices typically transmit 16-22 spectral channels, each modulated slowly in time. This coarse representation provides enough information to support speech understanding in quiet and rhythmic perception in music, but not enough to support speech understanding in noise or melody recognition. Melody recognition requires some capacity for complex pitch perception, which in turn depends strongly on access to spectral fine structure cues. Thus, temporal envelope cues are adequate for speech perception under optimal listening conditions, while spectral fine structure cues are needed for music perception. In this paper, we present recent experiments that directly measure CI users' melodic pitch perception using a melodic contour identification (MCI) task. While normal-hearing (NH) listeners' performance was consistently high across experiments, MCI performance was highly variable across CI users. CI users' MCI performance was significantly affected by instrument timbre, as well as by the presence of a competing instrument. In general, CI users had great difficulty extracting melodic pitch from complex stimuli. However, musically experienced CI users often performed as well as NH listeners, and MCI training in less-experienced subjects greatly improved performance. With fixed constraints on spectral resolution, such as occurs with hearing loss or an auditory prosthesis, training and experience can provide considerable improvements in music perception and appreciation.

Music in the lives of deaf children with cochlear implants

Present-day cochlear implants provide good temporal cues and coarse spectral cues. In general, these cues are adequate for perceiving speech in quiet backgrounds and for young children's acquisition of spoken language. They are inadequate, however, for conveying the rich pitch-patterning of music. As a result, many adults who become implant users after losing their hearing find music disappointing or unacceptable. By contrast, child implant users who were born deaf or became deaf as infants or toddlers typically find music interesting and enjoyable. They recognize popular songs that they hear regularly when the test materials match critical features of the original versions. For example, they can identify familiar songs from the original recordings with words and from versions that omit the words but preserve all other cues. They also recognize theme songs from their favorite television programs when presented in original or somewhat altered form. The motivation of children with implants for listening to music or melodious speech is evident well before they understand language. Within months after receiving their implant, they prefer singing to silence. They also prefer speech in the maternal style to typical adult speech and the sounds of their native language-to-be to those of a foreign language. An important task of future research is to ascertain the relative contributions of perceptual and motivational factors to the apparent differences between child and adult implant users.

The family oriented musical training for children with cochlear implants: speech and musical perception results of two year follow-up

OBJECTIVE

The purpose of this study is to determine whether children can gain benefit from training on pitch and music perception. Our main goals were to prepare a tool for training pitch and rhythm perception and evaluate musical attitude in children, to determine whether pitch and rhythm perception improve more rapidly through training and to assess the impact of training on speech perception.

METHOD

A family centred habilitation program based on musical training is developed. Nine newly implanted children who were switched on in HiRes and trained from the outset and 9 children using HiRes strategy who did not receive training both undergo assessments to determine pitch and rhythm perception skills and speech perception assessments. Music group was formed by the children who were implanted consecutively. As a control group, children who are being followed for another study which examines "the changes of sound quality perception, speech understanding, speech production, and communication mode" are included. The speech perception test battery contains a comprehensive range of age appropriate tasks covering detection, discrimination, identification, recognition and comprehension abilities. Also meaningful auditory integration scale (MAIS) or infant-toddler MAIS (if more appropriate) and the meaningful use of speech scale (MUSS) were administered in order to collect information about children's use of sound in everyday situations such as device bounding, alerting to sound and deriving meaning from auditory stimuli. Musical training program was based on a take-home electric keyboard which is used for listening to different pairs of notes. For this study, three octaves and one extra note at the high end of the keyboard were used. Children were expected to discriminate a pair of notes. Assessments of speech perception at pre-implant, 1-, 3-, 6-, 12-, 24-months post switch-on. By the end of the first and second years, parents were given the 'musical stages questionnaire' which covers some of the key areas of musical development to compare both groups' musical development.

RESULTS

Children who were involved in music study demonstrated significant familiarity in both determining pitch differences. No significant difference was found between music group compared with the non-trained group in terms of speech perception (p>0.05). However, by the end of 3rd month, music group came into prominence particularly at the rate of being linguistically/developmentally ready to carry out formal modified open-set speech perception evaluation (p<0.05). Both groups seemed to be developed similarly in sound awareness and general reaction, differentiating melody, dynamic, rhythmical changes and emotional aspects of musical development (p>0.05) whereas music group had more exposure to music at the end of the first year (p<0.05). However, by the end of the second year music group developed more than the control group in all aspects of musical skills (p<0.05).

CONCLUSION

Music training program helps appreciation of music and may enhance their progress in other auditory domains after cochlear implantation in children. While, effects of the musical training program on daily listening attitudes and social aspects such as closer parent-child relationship were significantly observed future training programs that should strive to improve satisfaction with music listening and its effect on auditory perception.

Vocal singing by prelingually-deafened children with cochlear implants

The coarse pitch information in cochlear implants might hinder the development of singing in prelingually-deafened pediatric users. In the present study, seven prelingually-deafened children with cochlear implants (5.4-12.3 years old) sang one song that was the most familiar to him or her. The control group consisted of 14 normal-hearing children (4.1-8.0 years old). The fundamental frequencies (F0) of each note in the recorded songs were extracted. The following five metrics were computed based on the reference music scores: (1) F0 contour direction of the adjacent notes, (2) F0 compression ratio of the entire song, (3) mean deviation of the normalized F0 across the notes, (4) mean deviation of the pitch intervals, and (5) standard deviation of the note duration differences. Children with cochlear implants showed significantly poorer performance in the pitch-based assessments than the normal-hearing children. No significant differences were seen between the two groups in the rhythm-based measure. Prelingually-deafened children with cochlear implants have significant deficits in singing due to their inability to manipulate pitch in the correct directions and to produce accurate pitch height. Future studies with a large sample size are warranted in order to account for the large variability in singing performance.