Effects of training on recognition of musical instruments presented through cochlear implant simulations

Person-centered aural rehabilitation program improved mood, cognition, and auditory processing in a professional musician who uses a hearing aid and cochlear implant: Case Report

Introduction

Aural rehabilitation focused on music for individuals with cochlear implants (CIs) and/or hearing aids (HAs) typically emphasizes perceptual skills rather than enjoyment of music. Yet, those with CIs and/or HAs often struggle to enjoy music, complaining that it sounds distorted with the implant or HAs. Typically, aural rehabilitation programs require a significant time commitment, but this may not be feasible or preferable for many patients. This study aimed to evaluate the efficacy of two individualized intensive 3-week home practice programs focused on enjoyment of music, a personal goal for this subject.

Methods

The subject was a professional musician who used a CI and HA. Cognitive measures of global cognitive function, executive function, processing speed, auditory working memory, visual-spatial abilities, verbal fluency, and auditory-verbal memory, as well as auditory electrophysiology (EEG) measures were conducted pre-post experiment 2. Two experiments were undertaken to evaluate responses to two practice programs that incorporated different variations in listening dosage and intervention activities.

Results

Experiment 1 resulted in minimal measurable improvements related to music likability ratings, with the highest dosage condition showing a small increase in average likability rating from baseline to week 3. The results of experiment 2 revealed an improvement in likability ratings only when dosage steadily increased each week. The subject also reported improved mood and decreased frustration during weeks two and three of experiment 2. Finally, we found improvement pre-post experiment 2 on several cognitive and EEG measures.

Discussion

The results of these experiments are encouraging and support the use of an individualized, person-centered, and semi-structured home practice program to increase music enjoyment and improve quality of life and auditory processing for individuals with hearing loss. Future studies should aim to increase sample size and explore pairing person-centered home practice programs with concurrent clinician-lead aural rehabilitation.

Evaluating Changes in Adult Cochlear Implant Users' Brain and Behavior Following Auditory Training

OBJECTIVES

To describe the effects of two types of auditory training on both behavioral and physiological measures of auditory function in cochlear implant (CI) users, and to examine whether a relationship exists between the behavioral and objective outcome measures.

DESIGN

This study involved two experiments, both of which used a within-subject design. Outcome measures included behavioral and cortical electrophysiological measures of auditory processing. In Experiment I, 8 CI users participated in a music-based auditory training. The training program included both short training sessions completed in the laboratory as well as a set of 12 training sessions that participants completed at home over the course of a month. As part of the training program, study participants listened to a range of different musical stimuli and were asked to discriminate stimuli that differed in pitch or timbre and to identify melodic changes. Performance was assessed before training and at three intervals during and after training was completed. In Experiment II, 20 CI users participated in a more focused auditory training task: the detection of spectral ripple modulation depth. Training consisted of a single 40-minute session that took place in the laboratory under the supervision of the investigators. Behavioral and physiologic measures of spectral ripple modulation depth detection were obtained immediately pre- and post-training. Data from both experiments were analyzed using mixed linear regressions, paired t tests, correlations, and descriptive statistics.

RESULTS

In Experiment I, there was a significant improvement in behavioral measures of pitch discrimination after the study participants completed the laboratory and home-based training sessions. There was no significant effect of training on electrophysiologic measures of the auditory N1-P2 onset response and acoustic change complex (ACC). There were no significant relationships between electrophysiologic measures and behavioral outcomes after the month-long training. In Experiment II, there was no significant effect of training on the ACC, although there was a small but significant improvement in behavioral spectral ripple modulation depth thresholds after the short-term training.

CONCLUSIONS

This study demonstrates that auditory training improves spectral cue perception in CI users, with significant perceptual gains observed despite cortical electrophysiological responses like the ACC not reliably predicting training benefits across short- and long-term interventions. Future research should further explore individual factors that may lead to greater benefit from auditory training, in addition to optimization of training protocols and outcome measures, as well as demonstrate the generalizability of these findings.

Integrating Emotion Perception in Rehabilitation Programs for Cochlear Implant Users: A Call for a More Comprehensive Approach

PURPOSE

Postoperative rehabilitation programs for cochlear implant (CI) recipients primarily emphasize enhancing speech perception. However, effective communication in everyday social interactions necessitates consideration of diverse verbal social cues to facilitate language comprehension. Failure to discern emotional expressions may lead to maladjusted social behavior, underscoring the importance of integrating social cues perception into rehabilitation initiatives to enhance CI users' well-being. After conventional rehabilitation, CI users demonstrate varying levels of emotion perception abilities. This disparity notably impacts young CI users, whose emotion perception deficit can extend to social functioning, encompassing coping strategies and social competence, even when relying on nonauditory cues such as facial expressions. Knowing that emotion perception abilities generally decrease with age, acknowledging emotion perception impairments in aging CI users is crucial, especially since a direct correlation between quality-of-life scores and vocal emotion recognition abilities has been observed in adult CI users. After briefly reviewing the scope of CI rehabilitation programs and summarizing the mounting evidence on CI users' emotion perception deficits and their impact, we will present our recommendations for embedding emotional training as part of enriched and standardized evaluation/rehabilitation programs that can improve CI users' social integration and quality of life.

CONCLUSIONS

Evaluating all aspects, including emotion perception, in CI rehabilitation programs is crucial because it ensures a comprehensive approach that enhances speech comprehension and the emotional dimension of communication, potentially improving CI users' social interaction and overall well-being. The development of emotion perception training holds promises for CI users and individuals grappling with various forms of hearing loss and sensory deficits. Ultimately, adopting such a comprehensive approach has the potential to significantly elevate the overall quality of life for a broad spectrum of patients.

Effects of Musical Training in Music Therapy Following Cochlear Implantation-A Case Report

The most prevalent sensory impairment impacting the elderly is age-related hearing loss (HL), which affects around 65% of individuals over the age of 60 years. This bilateral, symmetrical sensorineural impairment profoundly affects auditory perception, speech discrimination, and the overall understanding of auditory signals. Influenced by diverse factors, age-related HL can substantially influence an individual's quality of life and mental health and can lead to depression. Cochlear implantation (CI) stands as a standard intervention, yet despite advancements, music perception challenges persist, which can be addressed with individualized music therapy. This case report describes the journey of an 81-year-old musician through profound sensorineural hearing loss, cochlear implantation, and rehabilitative music therapy. Auditory evaluations, musical exercises, and quality of life assessments highlighted meaningful improvements in music perception, auditory skills, and overall satisfaction post-implantation. Music therapy facilitated emotional, functional, and musical levels of engagement, notably enhancing his ability to perceive melody, rhythm, and different instruments. Moreover, subjective assessments and audiograms indicated marked improvements in auditory differentiation, music enjoyment, and overall hearing thresholds. This comprehensive approach integrating bilateral CIs and music therapy showcased audiological and quality of life enhancements in an elderly individual with profound hearing loss, emphasizing the efficacy of this combined treatment approach.

Objective and Subjective Assessment of Music Perception and Musical Experiences in Young Cochlear Implant Users

For many individuals, music has a significant impact on the quality and enjoyability of life. Cochlear implant (CI) users must cope with the constraints that the CI imposes on music perception. Here, we assessed the musical experiences of young CI users and age-matched controls with normal hearing (NH). CI users and NH peers were divided into subgroups according to age: children and adolescents. Participants were tested on their ability to recognize vocal and instrumental music and instruments. A music questionnaire for pediatric populations (MuQPP) was also used. CI users and NH peers identified a similar percentage of vocal music. CI users were significantly worse at recognizing instruments (p < 0.05) and instrumental music (p < 0.05). CI users scored similarly to NH peers on the MuQPP, except for the musical frequency domain, where CI users in the children subgroup scored higher than their NH peers (p = 0.009). For CI users in the children subgroup, the identification of instrumental music was positively correlated with music importance (p = 0.029). Young CI users have significant deficits in some aspects of music perception (instrumental music and instrument identification) but have similar scores to NH peers in terms of interest in music, frequency of music exposure, and importance of music.

The Impact of Musical Rehabilitation on Complex Sound Perception in Cochlear Implant Users: A Systematic Review

OBJECTIVE

Musical rehabilitation has been used in clinical and nonclinical contexts to improve postimplantation auditory processing in implanted individuals. This systematic review aimed to evaluate the efficacy of music rehabilitation in controlled experimental and quasi-experimental studies on cochlear implant (CI) user speech and music perception.

DATABASES REVIEWED

PubMed/MEDLINE, EMBASE, Web of Science, PsycARTICLES, and PsycINFO databases through July 2022.

METHODS

Controlled experimental trials and prospective studies were included if they compared pretest and posttest data and excluded hearing aid-only users. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were then used to extract data from 11 included studies with a total of 206 pediatric and adult participants. Interventions included group music therapy, melodic contour identification training, auditory-motor instruction, or structured digital music training. Studies used heterogeneous outcome measures evaluating speech and music perception. Risk of bias was assessed using the National Heart, Lung, and Blood Institute Quality Assessment Tool.

RESULTS

A total of 735 studies were screened, and 11 met the inclusion criteria. Six trials reported both speech and music outcomes, whereas five reported only music perception outcomes after the intervention relative to control. For music perception outcomes, significant findings included improvements in melodic contour identification (five studies, p < 0.05), timbre recognition (three studies, p < 0.05), and song appraisal (three studies, p < 0.05) in their respective trials. For speech prosody outcomes, only vocal emotion identification demonstrated significant improvements (two studies, p < 0.05).

CONCLUSION

Music rehabilitation improves performance on multiple measures of music perception, as well as tone-based characteristics of speech (i.e., emotional prosody). This suggests that rehabilitation may facilitate improvements in the discrimination of spectrally complex signals.

Development of the Musi-CI Training, A Musical Listening Training for Cochlear Implant Users: A Participatory Action Research Approach

A cochlear implant (CI) is a prosthesis that allows people with severe to profound hearing loss to understand speech in quiet settings. However, listening to music presents a challenge to most CI users; they often do not enjoy music or avoid it altogether. The Musi-CI training course was developed for CI users with the goal of reducing music aversion and improving music enjoyment. A consortium was established consisting of a professional musician with CI, CI rehabilitation professionals and researchers. Participatory action research (PAR) was applied to develop and evaluate the training experiences, collaborating with 37 CI users during three cycles of eight training sessions, each held over a period of 3 months. Input and feedback were collected after each training session using questionnaires, observations and focus group interviews. Almost all participants (86%) completed the training. After completing the training a large majority of participants reported increased music appreciation, increased social participation in musical settings and a positive impact on general auditory perception. The resulting Musi-CI training programme focuses on music listening skills, self-efficacy, and self-motivation. It consists of exercises intended to strengthen attention and working memory, to improve beat and rhythm perception (with online rhythm exercises) and exercises to distinguish timbre of instruments and emotion in music. A Melody Game was developed to improve pitch and melodic contour discrimination.

Improved Music Perception after Music Therapy following Cochlear Implantation in the Elderly Population

Background: Cochlear implantation (CI) and the accompanying rehabilitation has become a routine procedure in hearing restoration. Literature is sparse on elderly CI recipients focusing on the issue of age and their inclined auditory resolution, taking their diminished cognitive function into account, which requires adaptation of rehabilitation programs to overcome habituation. Objective: This study aims to show that a few adjustments in the therapy program towards age, mental, physical and auditory condition significantly improve music perception and overall auditory benefit, hence normal communication and social interactions can be found. Methods: Subjects implanted with a CI 65 years or older were compared to age-matched normal hearing subjects. Questionnaires were administered before and after ten music therapy sessions, to evaluate the participant’s music habits, the perception of sound quality and self-awareness and hearing implant satisfaction. Results: The greatest benefit was seen in participants’ gain in self-confidence and enjoyable music perception. Not only did the amount of listening to music increase, but also the impression of sound quality changed from poor up to good/very good sound quality. Conclusions: The music therapy was well accepted and resulted in beneficial subjective as well as objective outcomes towards hearing and music impression, hence improved quality of life.

Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic Electrodes

The electrochemical performance of platinum electrodes was assessed in vitro and in vivo to determine the impact of electrode implantation and the relevance of in vitro testing in predicting in vivo behaviour. A significant change in electrochemical response was seen after electrode polarisation. As a result, initial in vitro measurements were poor predictors of subsequent measurements performed in vitro or in vivo. Charge storage capacity and charge density measurements from initial voltammetric measurements were not correlated with subsequent measurements. Electrode implantation also affected the electrochemical impedance. The typically reported impedance at 1 kHz was a very poor predictor of electrode performance. Lower frequencies were significantly more dependent on electrode properties, while higher frequencies were dependent on solution properties. Stronger correlations in impedance at low frequencies were seen between in vitro and in vivo measurements after electrode activation had occurred. Implanting the electrode increased the resistance of the electrochemical circuit, with bone having a higher resistivity than soft tissue. In contrast, protein fouling and fibrous tissue formation had a minimal impact on electrochemical response. In vivo electrochemical measurements also typically use a quasi-reference electrode, may operate in a 2-electrode system, and suffer from uncompensated resistance. The impact of these experimental conditions on electrochemical performance and the relevance of in vitro electrode assessment is discussed. Recommended in vitro testing protocols for assessing bionic electrodes are presented.

Interactive Evaluation of a Music Preprocessing Scheme for Cochlear Implants Based on Spectral Complexity Reduction

Music is difficult to access for the majority of CI users as the reduced dynamic range and poor spectral resolution in cochlear implants (CI), amongst others constraints, severely impair their auditory perception. The reduction of spectral complexity is therefore a promising means to facilitate music enjoyment for CI listeners. We evaluate a spectral complexity reduction method for music signals based on principal component analysis that enforces spectral sparsity, emphasizes the melody contour and attenuates interfering accompanying voices. To cover a wide range of spectral complexity reduction levels a new experimental design for listening experiments was introduced. It allows CI users to select the preferred level of spectral complexity reduction interactively and in real-time. Ten adult CI recipients with post-lingual bilateral profound sensorineural hearing loss and CI experience of at least 6 months were enrolled in the study. In eight consecutive sessions over a period of 4 weeks they were asked to choose their preferred version out of 10 different complexity settings for a total number of 16 recordings of classical western chamber music. As the experiments were performed in consecutive sessions we also studied a potential long term effect. Therefore, we investigated the hypothesis that repeated engagement with music signals of reduced spectral complexity leads to a habituation effect which allows CI users to deal with music signals of increasing complexity. Questionnaires and tests about music listening habits and musical abilities complemented these experiments. The participants significantly preferred signals with high spectral complexity reduction levels over the unprocessed versions. While the results of earlier studies comprising only two preselected complexity levels were generally confirmed, this study revealed a tendency toward a selection of even higher spectral complexity reduction levels. Therefore, spectral complexity reduction for music signals is a useful strategy to enhance music enjoyment for CI users. Although there is evidence for a habituation effect in some subjects, such an effect has not been significant in general.

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.

Musical and vocal emotion perception for cochlear implants users

Cochlear implants can successfully restore hearing in profoundly deaf individuals and enable speech comprehension. However, the acoustic signal provided is severely degraded and, as a result, many important acoustic cues for perceiving emotion in voices and music are unavailable. The deficit of cochlear implant users in auditory emotion processing has been clearly established. Yet, the extent to which this deficit and the specific cues that remain available to cochlear implant users are unknown due to several confounding factors. Here we assessed the recognition of the most basic forms of auditory emotion and aimed to identify which acoustic cues are most relevant to recognize emotions through cochlear implants. To do so, we used stimuli that allowed vocal and musical auditory emotions to be comparatively assessed while controlling for confounding factors. These stimuli were used to evaluate emotion perception in cochlear implant users (Experiment 1) and to investigate emotion perception in natural versus cochlear implant hearing in the same participants with a validated cochlear implant simulation approach (Experiment 2). Our results showed that vocal and musical fear was not accurately recognized by cochlear implant users. Interestingly, both experiments found that timbral acoustic cues (energy and roughness) correlate with participant ratings for both vocal and musical emotion bursts in the cochlear implant simulation condition. This suggests that specific attention should be given to these cues in the design of cochlear implant processors and rehabilitation protocols (especially energy, and roughness). For instance, music-based interventions focused on timbre could improve emotion perception and regulation, and thus improve social functioning, in children with cochlear implants during development.

Musical Rehabilitation in Adult Cochlear Implant Recipients With a Self-administered Software

OBJECTIVE

The goal of this study was to determine if a self-administered computer-based rehabilitation program could improve music appreciation and speech understanding in adults who have a cochlear implant (CI).

STUDY DESIGN

Prospective study.

SETTING

Tertiary adult CI program.

PATIENTS

Twenty-one postlingually deafened cochlear implant users between the ages of 27 and 79 years were recruited.

INTERVENTIONS(S)

A self-administered music rehabilitative software was designed to help improve the perception of musical patterns of increasing complexity, as well as pitch and timbre perception, premised on focused and divided attention. All participants completed a diagnostic music test before and after rehabilitative training, including tests of pitch and timbre perception and pattern identification with increasing levels of difficulty. Speech data in quiet and noise was also collected both pre- and post-training. Participants trained for a minimum of 3.5 hours a week, for 4 weeks.

MAIN OUTCOME MEASURE(S)

Mean changes in music perception and enjoyment as well as speech perception (IEEE sentence test in quiet and noise).

RESULTS

Post-training diagnostic test scores, as compared with pretraining scores, indicated significant improvements in musical pattern perception. Tests of speech perception in quiet and in noise were significantly improved in a subset of this cohort. All of the training participants thought that the training helped to improve their recognition skills, and found the program to be beneficial.

CONCLUSION

Despite the limitations of current CI technology, the results of this study suggest that auditory training can improve music perception skills, and possibly speech intelligibility, lending further support to rehabilitation being an integral part of the postimplantation paradigm.

[Music therapy in adults with cochlear implants : Effects on music perception and subjective sound quality]

BACKGROUND

People with severe hearing impairments and deafness can achieve good speech comprehension using a cochlear implant (CI), although music perception often remains impaired. A novel concept of music therapy for adults with CI was developed and evaluated in this study.

METHODS

This study included 30 adults with a unilateral CI following postlingual deafness. The subjective sound quality of the CI was rated using the hearing implant sound quality index (HISQUI) and musical tests for pitch discrimination, melody recognition and timbre identification were applied. As a control 55 normally hearing persons also completed the musical tests.

RESULTS

In comparison to normally hearing subjects CI users showed deficits in the perception of pitch, melody and timbre. Specific effects of therapy were observed in the subjective sound quality of the CI, in pitch discrimination into a high and low pitch range and in timbre identification, while general learning effects were found in melody recognition.

CONCLUSION

Music perception shows deficits in CI users compared to normally hearing persons. After individual music therapy in the rehabilitation process, improvements in this delicate area could be achieved.

A preliminary report of music-based training for adult cochlear implant users: Rationales and development

OBJECTIVE

This paper provides a preliminary report of a music-based training program for adult cochlear implant (CI) recipients. Included in this report are descriptions of the rationale for music-based training, factors influencing program development, and the resulting program components.

METHODS

Prior studies describing experience-based plasticity in response to music training, auditory training for persons with hearing impairment, and music training for CI recipients were reviewed. These sources revealed rationales for using music to enhance speech, factors associated with successful auditory training, relevant aspects of electric hearing and music perception, and extant evidence regarding limitations and advantages associated with parameters for music training with CI users. This informed the development of a computer-based music training program designed specifically for adult CI users.

RESULTS

Principles and parameters for perceptual training of music, such as stimulus choice, rehabilitation approach, and motivational concerns were developed in relation to the unique auditory characteristics of adults with electric hearing. An outline of the resulting program components and the outcome measures for evaluating program effectiveness are presented.

CONCLUSIONS

Music training can enhance the perceptual accuracy of music, but is also hypothesized to enhance several features of speech with similar processing requirements as music (e.g., pitch and timbre). However, additional evaluation of specific training parameters and the impact of music-based training on speech perception of CI users is required.

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.

Music therapy as specific and complementary training for adults after cochlear implantation: A pilot study

OBJECTIVES

Although cochlear implant (CI) users achieve good speech comprehension, they experience difficulty perceiving music and prosody in speech. As the provision of music training in rehabilitation is limited, a novel concept of music therapy for rehabilitation of adult CI users was developed and evaluated in this pilot study.

METHODS

Twelve unilaterally implanted, postlingually deafened CI users attended ten sessions of individualized and standardized training. The training started about 6 weeks after the initial activation of the speech processor. Before and after therapy, psychological and musical tests were applied in order to evaluate the effects of music therapy. CI users completed the musical tests in two conditions: bilateral (CI + contralateral, unimplanted ear) and unilateral (CI only).

RESULTS

After therapy, improvements were observed in the subjective sound quality (Hearing Implant Sound Quality Index) and the global score on the self-concept questionnaire (Multidimensional Self-Concept Scales) as well as in the musical subtests for melody recognition and for timbre identification in the unilateral condition. Discussion Preliminary results suggest improvements in subjective hearing and music perception, with an additional increase in global self-concept and enhanced daily listening capacities.

CONCLUSIONS

The novel concept of individualized music therapy seems to provide an effective treatment option in the rehabilitation of adult CI users. Further investigations are necessary to evaluate effects in the area of prosody perception and to separate therapy effects from general learning effects in CI rehabilitation.

Brain responses to musical feature changes in adolescent cochlear implant users

Cochlear implants (CIs) are primarily designed to assist deaf individuals in perception of speech, although possibilities for music fruition have also been documented. Previous studies have indicated the existence of neural correlates of residual music skills in postlingually deaf adults and children. However, little is known about the behavioral and neural correlates of music perception in the new generation of prelingually deaf adolescents who grew up with CIs. With electroencephalography (EEG), we recorded the mismatch negativity (MMN) of the auditory event-related potential to changes in musical features in adolescent CI users and in normal-hearing (NH) age mates. EEG recordings and behavioral testing were carried out before (T1) and after (T2) a 2-week music training program for the CI users and in two sessions equally separated in time for NH controls. We found significant MMNs in adolescent CI users for deviations in timbre, intensity, and rhythm, indicating residual neural prerequisites for musical feature processing. By contrast, only one of the two pitch deviants elicited an MMN in CI users. This pitch discrimination deficit was supported by behavioral measures, in which CI users scored significantly below the NH level. Overall, MMN amplitudes were significantly smaller in CI users than in NH controls, suggesting poorer music discrimination ability. Despite compliance from the CI participants, we found no effect of the music training, likely resulting from the brevity of the program. This is the first study showing significant brain responses to musical feature changes in prelingually deaf adolescent CI users and their associations with behavioral measures, implying neural predispositions for at least some aspects of music processing. Future studies should test any beneficial effects of a longer lasting music intervention in adolescent CI users.

The musician effect: does it persist under degraded pitch conditions of cochlear implant simulations?

Cochlear implants (CIs) are auditory prostheses that restore hearing via electrical stimulation of the auditory nerve. Compared to normal acoustic hearing, sounds transmitted through the CI are spectro-temporally degraded, causing difficulties in challenging listening tasks such as speech intelligibility in noise and perception of music. In normal hearing (NH), musicians have been shown to better perform than non-musicians in auditory processing and perception, especially for challenging listening tasks. This “musician effect” was attributed to better processing of pitch cues, as well as better overall auditory cognitive functioning in musicians. Does the musician effect persist when pitch cues are degraded, as it would be in signals transmitted through a CI? To answer this question, NH musicians and non-musicians were tested while listening to unprocessed signals or to signals processed by an acoustic CI simulation. The task increasingly depended on pitch perception: (1) speech intelligibility (words and sentences) in quiet or in noise, (2) vocal emotion identification, and (3) melodic contour identification (MCI). For speech perception, there was no musician effect with the unprocessed stimuli, and a small musician effect only for word identification in one noise condition, in the CI simulation. For emotion identification, there was a small musician effect for both. For MCI, there was a large musician effect for both. Overall, the effect was stronger as the importance of pitch in the listening task increased. This suggests that the musician effect may be more rooted in pitch perception, rather than in a global advantage in cognitive processing (in which musicians would have performed better in all tasks). The results further suggest that musical training before (and possibly after) implantation might offer some advantage in pitch processing that could partially benefit speech perception, and more strongly emotion and music perception.

Residual neural processing of musical sound features in adult cochlear implant users

Auditory processing in general and music perception in particular are hampered in adult cochlear implant (CI) users. To examine the residual music perception skills and their underlying neural correlates in CI users implanted in adolescence or adulthood, we conducted an electrophysiological and behavioral study comparing adult CI users with normal-hearing age-matched controls (NH controls). We used a newly developed musical multi-feature paradigm, which makes it possible to test automatic auditory discrimination of six different types of sound feature changes inserted within a musical enriched setting lasting only 20 min. The presentation of stimuli did not require the participants’ attention, allowing the study of the early automatic stage of feature processing in the auditory cortex. For the CI users, we obtained mismatch negativity (MMN) brain responses to five feature changes but not to changes of rhythm, whereas we obtained MMNs for all the feature changes in the NH controls. Furthermore, the MMNs to deviants of pitch of CI users were reduced in amplitude and later than those of NH controls for changes of pitch and guitar timber. No other group differences in MMN parameters were found to changes in intensity and saxophone timber. Furthermore, the MMNs in CI users reflected the behavioral scores from a respective discrimination task and were correlated with patients’ age and speech intelligibility. Our results suggest that even though CI users are not performing at the same level as NH controls in neural discrimination of pitch-based features, they do possess potential neural abilities for music processing. However, CI users showed a disrupted ability to automatically discriminate rhythmic changes compared with controls. The current behavioral and MMN findings highlight the residual neural skills for music processing even in CI users who have been implanted in adolescence or adulthood. Highlights: -

Automatic brain responses to musical feature changes reflect the limitations of central auditory processing in adult Cochlear Implant users.

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The brains of adult CI users automatically process sound features changes even when inserted in a musical context.

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CI users show disrupted automatic discriminatory abilities for rhythm in the brain.

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Our fast paradigm demonstrate residual musical abilities in the brains of adult CI users giving hope for their future rehabilitation.

Auditory Training: Evidence for Neural Plasticity in Older Adults

Improvements in digital amplification, cochlear implants, and other innovations have extended the potential for improving hearing function; yet, there remains a need for further hearing improvement in challenging listening situations, such as when trying to understand speech in noise or when listening to music. Here, we review evidence from animal and human models of plasticity in the brain's ability to process speech and other meaningful stimuli. We considered studies targeting populations of younger through older adults, emphasizing studies that have employed randomized controlled designs and have made connections between neural and behavioral changes. Overall results indicate that the brain remains malleable through older adulthood, provided that treatment algorithms have been modified to allow for changes in learning with age. Improvements in speech-in-noise perception and cognition function accompany neural changes in auditory processing. The training-related improvements noted across studies support the need to consider auditory training strategies in the management of individuals who express concerns about hearing in difficult listening situations. Given evidence from studies engaging the brain's reward centers, future research should consider how these centers can be naturally activated during training.

The Effects of Training on Recognition of Musical Instruments by Adults with Cochlear Implants

This study examines the efficiency and effectiveness of three types of training on recognition of musical instruments by adults with cochlear implants (CI). Seventy-one adults with CIs were randomly assigned to one of three training conditions: feedback on response accuracy, feedback-plus (response accuracy plus correct answer), and direct instruction. Each participant completed three training sessions per week over a five-week time period in which they listened to recorded excerpts of eight different musical instruments. Results showed significant pre-to-posttest improvement in music instrument recognition accuracy for all three training conditions (22.9-25.7%, p< 0.0001). Time when tested (week), bilateral CI use, and age were significant predictors of performance. Participants who wore bilateral implants scored significantly higher than participants with unilateral implants at all three time points; hearing aid use was not a significant predictor. These results may have practical implications for numerous types of auditory rehabilitation for persons who use CIs.

Musical sound quality impairments in cochlear implant (CI) users as a function of limited high-frequency perception

The purpose of this study was to (a) apply the musical sound quality assessment method, Cochlear Implant-MUltiple Stimulus with Hidden Reference and Anchor (CI-MUSHRA), to quantify musical sound quality deficits in CI (cochlear implant) users with respect to high-frequency loss, and (b) assess possible correlations between CI-MUSHRA performance and self-reported musical sound quality, as assessed by more traditional rating scales. Five versions of real-world musical stimuli were created: 8-,4-, and 2-kHz low-pass-filtered (LPF) versions with increasing high-frequency removal, a composite stimulus containing a 1-kHz LPF-filtered version and white noise ("anchor"), and an unaltered version ("hidden reference"). Using the CI-MUSHRA methodology, these versions were simultaneously presented to participants in addition to a labeled reference. Participants listened to all versions and provided ratings based on a 100-point scale that reflected perceived sound quality difference among the versions. A total of 25 musical stimuli were tested. As comparison measures, participants completed four Visual Analogue Scales (VAS) to assess musical sound quality. Overall, compared to normal hearing (NH) listeners, CI users demonstrated an impaired ability to discriminate between unaltered and altered musical stimuli with variable amounts of high-frequency information removed. Performance using CI-MUSHRA to evaluate this parameter did not correlate to measurements of musical sound quality, as assessed by VAS. This study identified high-frequency loss as one acoustic parameter contributing to overall CI-mediated musical sound quality limitations. CI-MUSHRA provided a quantitative assessment of musical sound quality. This method offers the potential to quantify CI impairments of many different acoustic parameters related to musical sound quality in the future.

MUSIC APPRECIATION AND TRAINING FOR COCHLEAR IMPLANT RECIPIENTS: A REVIEW

In recent years, there has been increasing interest in music perception of cochlear implant (CI) recipients, and a growing body of research conducted in this area. The majority of these studies have examined perceptual accuracy for pitch, rhythm, and timbre. Another important, but less commonly studied aspect of music listening is appreciation, or appraisal. Despite the ongoing research into potential technological improvements that may improve music perception for recipients, both perceptual accuracy and appreciation generally remain poor for most recipients. Whilst perceptual accuracy for music is important, appreciation and enjoyment also warrants research as it also contributes to clinical outcomes and perceived benefits. Music training is being shown to offer excellent potential for improving music perception and appreciation for recipients.Therefore, the primary topics of this review are music appreciation and training. However, a brief overview of the psychoacoustic, technical, and physiological factors associated with a recipient's perception of music is provided, as these are important factors in understanding the listening experience for CI recipients. The purpose of this review is to summarize key papers that have investigated these issues, in order to demonstrate that i) music enjoyment and appraisal is an important and valid consideration in evaluating music outcomes for recipients, and ii) that music training can improve music listening for many recipients, and is something that can be offered to persons using current technology.

Temporal feature perception in cochlear implant users

For the perception of timbre of a musical instrument, the attack time is known to hold crucial information. The first 50 to 150 ms of sound onset reflect the excitation mechanism, which generates the sound. Since auditory processing and music perception in particular are known to be hampered in cochlear implant (CI) users, we conducted an electroencephalography (EEG) study with an oddball paradigm to evaluate the processing of small differences in musical sound onset. The first 60 ms of a cornet sound were manipulated in order to examine whether these differences are detected by CI users and normal-hearing controls (NH controls), as revealed by auditory evoked potentials (AEPs). Our analysis focused on the N1 as an exogenous component known to reflect physical stimuli properties as well as on the P2 and the Mismatch Negativity (MMN). Our results revealed different N1 latencies as well as P2 amplitudes and latencies for the onset manipulations in both groups. An MMN could be elicited only in the NH control group. Together with additional findings that suggest an impact of musical training on CI users’ AEPs, our findings support the view that impaired timbre perception in CI users is at partly due to altered sound onset feature detection.

Music perception ability of korean adult cochlear implant listeners

Objectives

Although the cochlear implant (CI) is successful for understanding speech in patients with severe to profound hearing loss, listening to music is a challenging task to most CI listeners. The purpose of this study was to assess music perception ability and to provide clinically useful information regarding CI rehabilitation.

Methods

Ten normal hearing and ten CI listeners with implant experience, ranging 2 to 6 years, participated in the subtests of pitch, rhythm, melody, and instrument. A synthesized piano tone was used as musical stimuli. Participants were asked to discriminate two different tones during the pitch subtest. The rhythm subtest was constructed with sets of five, six, and seven intervals. The melody & instrument subtests assessed recognition of eight familiar melodies and five musical instruments from a closed set, respectively.

Results

CI listeners performed significantly poorer than normal hearing listeners in pitch, melody, and instrument identification tasks. No significant differences were observed in rhythm recognition between groups. Correlations were not found between music perception ability and word recognition scores.

Conclusion

The results are consistent with previous studies that have shown that pitch, melody, and instrument identifications are difficult to identify for CI users. Our results can provide fundamental information concerning the development of CI rehabilitation tools.

Midbrain responses to micro-stimulation of the cochlea using high density thin-film arrays

A broader activation of auditory nerve fibres than normal using a cochlear implant contributes to poor frequency discrimination. As cochlear implants also deliver a restricted dynamic range, this hinders the ability to segregate sound sources. Better frequency coding and control over amplitude may be achieved by limiting current spread during electrical stimulation of the cochlea and positioning electrodes closer to the modiolus. Thin-film high density microelectrode arrays and conventional platinum ring electrode arrays were used to stimulate the cochlea of urethane-anaesthetized rats and responses compared. Neurophysiological recordings were taken at 197 multi-unit clusters in the central nucleus of the inferior colliculus (CIC), a site that receives direct monaural innervation from the cochlear nucleus. CIC responses to both the platinum ring and high density electrodes were recorded and differences in activity to changes in stimulation intensity, thresholds and frequency coding of neural activation were examined. The high density electrode array elicited less CIC activity at nonspecific frequency regions than the platinum ring electrode array. The high density electrode array produced significantly lower thresholds and larger dynamic ranges than the platinum ring electrode array when positioned close to the modiolus. These results suggest that a higher density of stimulation sites on electrodes that effectively 'aim' current, combined with placement closer to the modiolus would permit finer control over charge delivery. This may equate to improved frequency specific perception and control over amplitude when using future cochlear implant devices.

Current research on music perception in cochlear implant users

The authors present a comprehensive review of the state of music perception with cochlear implant (CI) users. They discuss methods of assessment and results of studies of the aspects of music perception, melody, timbre, rhythm, and so forth in individuals with cochlear implants. They discuss neural mechanisms of music perception and the anticipation of broader acceptance of standardized tests for music perception in CI users.

Music Perception of Cochlear Implant Recipients with Implications for Music Instruction: A Review of Literature

This review of literature presents a systematic analysis of the capabilities and limitations of cochlear implant recipients regarding music perception. Specifically, it a) analyzes individual components of music (e.g., rhythm, timbre, and pitch) as they interface with the technical characteristics of cochlear implants and the perceptual abilities of cochlear implant recipients; and b) describes accommodations for music instruction that support successful participation of children with cochlear implants. This article consolidates research studies from various disciplines (audiology, hearing science, speech-language pathology, cochlear implants, and music therapy) to provide practical recommendations for educators in fostering the musical growth of children with cochlear implants.