Effects of various electrode configurations on music perception, intonation and speaker gender identification

Perception of Prosody in Hearing-Impaired Individuals and Users of Hearing Assistive Devices: An Overview of Recent Advances

PURPOSE

Prosody perception is an essential component of speech communication and social interaction through which both linguistic and emotional information are conveyed. Considering the importance of the auditory system in processing prosody-related acoustic features, the aim of this review article is to review the effects of hearing impairment on prosody perception in children and adults. It also assesses the performance of hearing assistive devices in restoring prosodic perception.

METHOD

Following a comprehensive online database search, two lines of inquiry were targeted. The first summarizes recent attempts toward determining the effects of hearing loss and interacting factors such as age and cognitive resources on prosody perception. The second analyzes studies reporting beneficial or detrimental impacts of hearing aids, cochlear implants, and bimodal stimulation on prosodic abilities in people with hearing loss.

RESULTS

The reviewed studies indicate that hearing-impaired individuals vary widely in perceiving affective and linguistic prosody, depending on factors such as hearing loss severity, chronological age, and cognitive status. In addition, most of the emerging information points to limitations of hearing assistive devices in processing and transmitting the acoustic features of prosody.

CONCLUSIONS

The existing literature is incomplete in several respects, including the lack of a consensus on how and to what extent hearing prostheses affect prosody perception, especially the linguistic function of prosody, and a gap in assessing prosody under challenging listening situations such as noise. This review article proposes directions that future research could follow to provide a better understanding of prosody processing in those with hearing impairment, which may help health care professionals and designers of assistive technology to develop innovative diagnostic and rehabilitation tools.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21809772.

Recognizing Voices Through a Cochlear Implant: A Systematic Review of Voice Perception, Talker Discrimination, and Talker Identification

OBJECTIVE

Some cochlear implant (CI) users report having difficulty accessing indexical information in the speech signal, presumably due to limitations in the transmission of fine spectrotemporal cues. The purpose of this review article was to systematically review and evaluate the existing research on talker processing in CI users. Specifically, we reviewed the performance of CI users in three types of talker- and voice-related tasks. We also examined the different factors (such as participant, hearing, and device characteristics) that might influence performance in these specific tasks.

DESIGN

We completed a systematic search of the literature with select key words using citation aggregation software to search Google Scholar. We included primary reports that tested (a) talker discrimination, (b) voice perception, and (c) talker identification. Each report must have had at least one group of participants with CIs. Each included study was also evaluated for quality of evidence.

RESULTS

The searches resulted in 1,561 references, which were first screened for inclusion and then evaluated in full. Forty-three studies examining talker discrimination, voice perception, and talker identification were included in the final review. Most studies were focused on postlingually deafened and implanted adult CI users, with fewer studies focused on prelingual implant users. In general, CI users performed above chance in these tasks. When there was a difference between groups, CI users performed less accurately than their normal-hearing (NH) peers. A subset of CI users reached the same level of performance as NH participants exposed to noise-vocoded stimuli. Some studies found that CI users and NH participants relied on different cues for talker perception. Within groups of CI users, there is moderate evidence for a bimodal benefit for talker processing, and there are mixed findings about the effects of hearing experience.

CONCLUSIONS

The current review highlights the challenges faced by CI users in tracking and recognizing voices and how they adapt to it. Although large variability exists, there is evidence that CI users can process indexical information from speech, though with less accuracy than their NH peers. Recent work has described some of the factors that might ease the challenges of talker processing in CI users. We conclude by suggesting some future avenues of research to optimize real-world speech outcomes.

Variations in Cochlear Size of Cochlear Implant Candidates

Introduction  The cochlear anatomy varies in each individual, and that has an impact on decisions regarding the insertion of electrodes. The measurement of the cochlear size is the routine examination required to choose the proper cochlear implant (CI) electrodes.

Objective  To acquire normative data on the size of the cochlea (length, width, height, scala timpani [ST] height, cochlear duct length [CDL]) of CI candidates in Medan, Indonesia.

Methods  This descriptive study was conducted based on high-resolution computed tomography (HRCT) temporal bone data and on HRCT temporal data manipulated to reconstruct three-dimensional (3D) multiplanar images with OsiriX MD DICOM Viewer version 9.5.1 (Pixmeo SARL, Bernex, Geneva, Switzerland) viewer of 18 patients (36 ears) who were CI candidates in Medan, Indonesia, in order to determine cochlear length (A), cochlear width, cochlear height, ST height and CDL, calculated through a simple mathematical function.

Results  The average cochlear length (A) was 8.75 mm (standard deviation [SD] = 0.31 mm); the average cochlear width was 6.53 mm (SD = 0.35 mm); the average cochlear height was 3.26 mm (SD = 0.24 mm) and the average ST height at the basal cochlea was 1.00 mm (SD = 0.1 mm); and 0.71 mm (SD = 0.1 mm) at the half turn of cochlea. The average total CDL was 32.45 mm (SD = 1.31 mm; range: 30.01–34.83 mm).

Conclusion  The cochlear size varies in each individual; therefore, the temporal bone measurement of CI candidates using HRCT is essential: for the selection of suitable implant electrodes; to minimize cochlear damages at the insertion of the electrode arrays; and to maximize the hearing improvements.

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.

Using the HISQUI29 to assess the sound quality levels of Spanish adults with unilateral cochlear implants and no contralateral hearing

To evaluate cochlear implant (CI) users' self-reported level of sound quality and quality of life (QoL). Sound quality was self-evaluated using the hearing implant sound quality index (HISQUI29). HISQUI29 scores were further examined in three subsets. QoL was self-evaluated using the glasgow benefit inventory (GBI). GBI scores were further examined in three subsets. Possible correlations between the HISQUI29 and GBI were explored. Additional possible correlations between these scores and subjects' pure tone averages, speech perception scores, age at implantation, duration of hearing loss, duration of CI use, gender, and implant type were explored. Subjects derived a "moderate" sound quality level from their CI. Television, radio, and telephone tasks were easier in quiet than in background noise. 89 % of subjects reported their QoL benefited from having a CI. Mean total HISQUI29 score significantly correlated with all subcategories of the GBI. Age at implantation inversely correlated with the total HISQUI29 score and with television and radio understanding. Sentence in noise scores significantly correlated with all sound perception scores. Women had a better mean score in music perception and in telephone use than did men. CI users' self-reported levels of sound quality significantly correlated with their QoL. Cochlear implantation had a beneficial impact on subjects' QoL. Understanding speech is easier in quiet than in noise. Music perception remains a challenge for many CI users. The HISQUI29 and the GBI can provide useful information about the everyday effects of future treatment modalities, rehabilitation strategies, and technical developments.

Neural correlates of auditory-cognitive processing in older adult cochlear implant recipients

With the growing number of older adults receiving cochlear implants (CI), there is general agreement that substantial benefits can be gained. Nonetheless, variability in speech perception performance is high, and the relative contribution and interactions among peripheral, central-auditory, and cognitive factors are not fully understood. The goal of the present study was to compare auditory-cognitive processing in older-adult CI recipients with that of older normal-hearing (NH) listeners by means of behavioral and electrophysiologic manifestations of a high-load cognitive task. Auditory event-related potentials (AERPs) were recorded from 9 older postlingually deafened adults with CI (age at CI >60) and 10 age-matched listeners with NH, while performing an auditory Stroop task. Participants were required to classify the speaker's gender (male/female) that produced the words 'mother' or 'father' while ignoring the irrelevant congruent or incongruent word meaning. Older CI and NH listeners exhibited comparable reaction time, performance accuracy, and initial sensory-perceptual processing (i.e. N1 potential). Nonetheless, older CI recipients showed substantially prolonged and less efficient perceptual processing (i.e. P3 potential). Congruency effects manifested in longer reaction time (i.e. Stroop effect), execution time, and P3 latency to incongruent versus congruent stimuli in both groups in a similar fashion; however, markedly prolonged P3 and shortened execution time were evident in older CI recipients. Collectively, older adults (CI and NH) employed a combined perceptual and postperceptual conflict processing strategy; nonetheless, the relative allotment of perceptual resources was substantially enhanced to maintain adequate performance in CI recipients. In sum, the recording of AERPs together with the simultaneously obtained behavioral measures during a Stroop task exposed a differential time course of auditory-cognitive processing in older CI recipients that was not manifested in the behavioral end products of processing. These data may have implications regarding clinical evaluation and rehabilitation procedures that should be tailored specifically for this unique group of patients.