Impact of Noise Reduction Algorithm in Cochlear Implant Processing on Music Enjoyment

The Association of Hearing Loss With Active Music Enjoyment in Hearing Aid Users

OBJECTIVE

Hearing aids (HAs) are designed for speech rather than music listening. The impact of HAs on music enjoyment is poorly studied. We examine the effect of HAs on active music enjoyment in individuals with varying levels of hearing loss (HL).

STUDY DESIGN

Cross-sectional study.

SETTING

Tertiary medical center and community.

METHODS

Adult (≥18 years) bilateral HA users and normal hearing (NH) controls actively listened to musical stimuli and rated their enjoyment across 3 measures (pleasantness, musicality, naturalness) with and without HAs using a visual analog scale. Multivariable linear regression was used to assess the association between HL (measured by a pure-tone average [PTA] and word recognition score [WRS] of the better ear) and music enjoyment with and without HAs, adjusting for covariates. Music enjoyment was compared between HA users and NH controls, and HA users with and without their HAs.

RESULTS

One hundred bilateral HA users (mean age 66.0 years, 52% female, better ear mean [SD] PTA 50.2 [13.5] dBHL, mean WRS 84.5 [16.5]%) completed the study. Increasing severity of HL (PTA) was independently associated with decreased music enjoyment (pleasantness, musicality, naturalness) with and without HAs (p < .05). HA usage increased music enjoyment (musicality) in those with moderate to moderately severe HL. Music enjoyment in NH controls (n = 20) was significantly greater across all measures compared to HA users.

CONCLUSION

Increased severity of HL is associated with decreased music enjoyment that can be enhanced with HA usage. Thus, HA usage can positively enhance both speech and music appreciation.

Optimization of Sound Coding Strategies to Make Singing Music More Accessible for Cochlear Implant Users

Cochlear implants (CIs) are implantable medical devices that can partially restore hearing to people suffering from profound sensorineural hearing loss. While these devices provide good speech understanding in quiet, many CI users face difficulties when listening to music. Reasons include poor spatial specificity of electric stimulation, limited transmission of spectral and temporal fine structure of acoustic signals, and restrictions in the dynamic range that can be conveyed via electric stimulation of the auditory nerve. The coding strategies currently used in CIs are typically designed for speech rather than music. This work investigates the optimization of CI coding strategies to make singing music more accessible to CI users. The aim is to reduce the spectral complexity of music by selecting fewer bands for stimulation, attenuating the background instruments by strengthening a noise reduction algorithm, and optimizing the electric dynamic range through a back-end compressor. The optimizations were evaluated through both objective and perceptual measures of speech understanding and melody identification of singing voice with and without background instruments, as well as music appreciation questionnaires. Consistent with the objective measures, results gathered from the perceptual evaluations indicated that reducing the number of selected bands and optimizing the electric dynamic range significantly improved speech understanding in music. Moreover, results obtained from questionnaires show that the new music back-end compressor significantly improved music enjoyment. These results have potential as a new CI program for improved singing music perception.

Hearing Aids Enhance Music Enjoyment in Individuals With Hearing Loss

OBJECTIVE

To investigate music appreciation in hearing aid (HA) users with varying levels of hearing loss (HL).

STUDY DESIGN

Cross-sectional, within-subjects design.

SETTING

Tertiary medical center, community.

PATIENTS

Adults (≥18 yr) bilateral HA users.

INTERVENTIONS

HA usage.

MAIN OUTCOME MEASURES

Outcome variables included self-reported music enjoyment measures (pleasantness, musicality, naturalness) with and without HAs assessed with visual analogue scales (10 indicates highest level of enjoyment, 0 the least). Exposure variables include HL (better ear pure-tone average) and speech discrimination (word recognition scores [WRS]). Demographic information was collected.

RESULTS

One hundred nine bilateral HA users completed the study. Mean (standard deviation) age was 66.6 years (16.8 yr); 52.3% were female patients. Mean (standard deviation) better ear pure-tone average was 51.1 dB (16.3 dB) HL. Increased severity of HL and worse WRS were associated with decreased music enjoyment ( p < 0.05) across all measures without HAs, adjusting for sex, age, education, race, HA type, age of HL diagnosis, duration of HL, duration of HA use, musical preference, and musical experience. However, these associations were attenuated or no longer significant with HA usage. Moreover, among all subjects, HAs (vs. no HAs) provided increased music enjoyment in pleasantness (HA, 6.94, no HA, 5.74; p < 0.01), musicality (HA, 7.35; no HA, 6.13, p < 0.01), and naturalness (HA, 6.75; no HA, 6.02; p = 0.02).

CONCLUSION

HA users report increased music enjoyment with HAs compared with without HAs. Increased severity of HL and worse WRS were independently associated with decreased unaided music enjoyment. HA usage seems to mitigate this effect, particularly for those with worse HL.

Masking and noise reduction processing of music signals in reverberant music

Noise will be inevitably mixed with music signals in the recording process. To improve the quality of music signals, it is necessary to reduce noise as much as possible. This article briefly introduces noise, the masking effect, and the spectral subtraction method for reducing noise in reverberant music. The spectral subtraction method was improved by the human ear masking effect to enhance its noise reduction performance. Simulation experiments were carried out on the traditional and improved spectral subtraction methods. The results showed that the improved spectral subtraction method could reduce the noise in reverberant music more effectively; under an objective evaluation criterion, the signal-to-noise ratio, the de-reverberated music signal processed by the improved spectral subtraction method had a higher signal-to-noise ratio; under a subjective evaluation criterion, mean opinion score (MOS), the de-reverberated music signal processed by the improved spectral subtraction method also had a better evaluation.

An evaluation of music perception, appreciation, and overall music enjoyment in prelingual paediatric cochlear implant users utilizing simplified techniques: An Indian study

INTRODUCTION

This study was aimed to evaluate the speech abilities, music habits, ability to perceive and enjoy music in prelingual paediatric cochlear implantees between the age group (18-84 months). Testing paediatric CI recipients for their music habits is challenging. This study offers some unique yet simplified tools to test musical parameters in paediatric CI recipients.

MATERIAL METHODS

Twenty-seven paediatric CI recipients who had received at least one year of auditory verbal therapy post-implantation were selected. They were tested for their speech abilities using the CAP (Category of Auditory Performance) and SIR (Speech Intelligibility Ratings) score. Music habits (Musicality Rating Scale/MRS), music perception (Pitch, timbre, melody) and music enjoyment (Subjective Assessment of Music Enjoyment/SAME) were assessed using various tools. All these parameters were compared with age and sex-matched controls who had normal hearing.

RESULTS

Simple pitch discrimination, timbre recognition, and melody identification was observed in 29.60%, 37.03%, and 37.03% of implantees, respectively, compared to 88.88%, 81.48% and 88.88%, in normal-hearing children. The mean scores of CAP, SIR and MRS in cochlear implant users who perceived pitch timbre and melody differed significantly from those who did not. The mean SAME score of the normal-hearing group [4.37 ± 0.74] differs significantly from the paediatric cochlear implant user group [2.59 ± 1.47]. (p < .000).

CONCLUSION

This study offers some novel, simplified tools to assess music habits in paediatric cochlear implantees. These can be utilized in low resource settings and can be helpful for rehabilitationists training these children.

Novel Web-Based Music Re-Engineering Software for Enhancement of Music Enjoyment Among Cochlear Implantees

OBJECTIVES

Cochlear implant (CI) listeners experience diminished music perception and enjoyment from a variety of patient-related and implant-related factors. We investigate the hypothesis that patient-directed music re-engineering may enhance music enjoyment with CI.

STUDY DESIGN

Prospective cohort study.

SETTING

Academic cochlear implant center.

SUBJECTS AND METHODS

A multidisciplinary team of neurotologists, audiologists, and a sound/audio engineer collaborated with a web developer to create a music re-engineering application. Experienced adult CI listeners rated original excerpts from five major genres of music on enjoyment using a visual analog scale (VAS). Subjects were then allowed to re-engineer the original by adjusting treble frequencies, bass frequencies, percussion emphasis, and reverberation and again rated on enjoyment.

RESULTS

Total of 46 subjects, with a mean age of 57.6 years (SD = 16; range, 18-90) participated in the study. User-mixed audio was rated higher across all measures of enjoyment than original recordings (mean difference +0.92; p < 0.05, CI [0.22, 1.62]), an effect that was seen across all genres except for country music. Subjects preferred louder bass frequencies (mean difference +7.1 dB; p < 0.01, CI [2.15, 24.3]) and more reverberation (mean difference +6.6 ms; p < 0.01, CI [2.85, 10.7]). Re-engineered music increased enjoyment in 57%, and 79% reported an interest in being able to mix music of their own choosing.

CONCLUSION

User-directed music re-engineering increases music enjoyment for CI listeners. The cochlear implantee preferred heightened bass, reverberation, and treble across musical genres. These findings support the implementation of patient-directed music re-engineering to enhance music enjoyment with technology that is readily available today.

Music Appreciation after Cochlear Implantation in Adult Patients: A Systematic Review

Objective

The cochlear implant (CI) improves quality of life for people who are severely and profoundly deafened, allowing implantees to perceive speech at levels similar to those of individuals with normal hearing. However, patients with CIs generally report a reduced appreciation of music after implantation. We aimed to systematically review the English-language literature for studies evaluating music enjoyment and perception among adult patients with CIs.

Data Sources

A systematic review of PubMed/MEDLINE, Scopus, Embase, and the Cochrane Library.

Review Methods

The PRISMA statement was utilized to identify English-language studies reporting music appreciation among adults with CIs. Two independent reviewers performed searches through May 2017. Included studies investigated parameters related to music enjoyment and music perception, including (1) pitch and timbre perception, (2) noise-canceling algorithms, and (3) the presence of dissonant chords, lyrics, or visual cues.

Results

A total of 508 articles were screened for relevance. Forty-one full-text articles were evaluated, and 18 met final inclusion criteria. Studies used heterogeneous methods of outcome measurement for identifying music appreciation. The outcome measures suggest that rhythm and lyrics are important components of enjoyment. Patients with CIs had difficulty with pitch and timbre perception.

Conclusion

The heterogeneous outcome measures identified in this systematic review suggest that rhythm and lyrics are important components of enjoyment, while patients with CIs had difficulty with pitch and timbre perception. Because there is no standardized reporting metric for music appreciation among adult patients with CIs, a standardized validated outcome-measuring tool is warranted.