Perception of Environmental Sounds in Cochlear Implant Users: A Systematic Review

Objectives: Improved perception of environmental sounds (PES) is one of the primary benefits of cochlear implantation (CI). However, past research contains mixed findings on PES ability in contemporary CI users, which at times contrast with anecdotal clinical reports. The present review examined extant PES research to provide an evidence basis for clinical counseling, identify knowledge gaps, and suggest directions for future work in this area of CI outcome assessment.Methods: Six electronic databases were searched using medical subject headings (MeSH) and keywords broadly identified to reference CI and environmental sounds. Records published between 2000 and 2021 were screened by two independent reviewers in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement to identify studies that met the inclusion criteria. Data were subsequently extracted and evaluated according to synthesis without-meta-analysis (SWiM) guidelines.Results: Nineteen studies met the inclusion criteria. Most examined PES in post-lingually implanted adults, with one study focused on pre/perilingual adults. Environmental sound identification (ESI) in quiet using open- or closed-set response format was most commonly used in PES assessment, included in all selected studies. ESI accuracy in CI children (3 studies) and adults (16 studies), was highly variable but generally mediocre (means range: 31–87%). Only two studies evaluated ESI performance prospectively before and after CI, while most studies were cross-sectional. Overall, CI performance was consistently lower than that of normal-hearing peers. No significant differences in identification accuracy were reported between CI candidates and CI users. Environmental sound identification correlated in CI users with measures of speech perception, music and spectro-temporal processing.Conclusion: The findings of this systematic review indicate considerable limitations in the current knowledge of PES in contemporary CI users, especially in pre/perilingual late-implanted adults and children. Although no overall improvement in PES following implantation was found, large individual variability and existing methodological limitations in PES assessment may potentially obscure potential CI benefits for PES. Further research in this ecologically relevant area of assessment is needed to establish a stronger evidence basis, identify CI users with significant deficits, and improve CI users' safety and satisfaction through targeted PES rehabilitation.

İnkomplet partisyon tip II bulunan unilateral ve bimodal koklear implant kullanıcılarının konuşma, uzaysal algı ve işitme kalitesinin değerlendirilmesi

Evaluation of the speech, spatial and qualities of hearing in unilateral and bimodal cochlear implant users with incomplete partition type II Objective: The aim of this study was to perform a scale-based assessment of the hearing abilities of cochlear implant users with IP type II malformation and normal cochlea, including discrimination, orientation, and positioning of speech and environmental sounds in their environment. Material and Methods: A total of 30 cochlear implant users, 15 participants with IP-II inner ear anomalies and 15 participants with normal cochlea, aged 18-55 years were included in this study. All participants included in the study are unilateral CI and bimodal users. Participants were assessed using the Speech, Spatial, and Hearing Qualities Scale (SSQ). Results: When cochlear implant users with IP-II malformations and cochlear implant users with normal cochlea individually scored auditory abilities, the results were similar. It was observed that bimodal listeners tended to have all subdomains and overall SSQ scores compared to use of unilateral CI. Conclusion: It is very important to benefit from the advantages of binaural hearing in hearing sounds. It is thought that the use of scales as well as routine audiological evaluation batteries in the follow-up processes of cochlear implant users will be beneficial for audiologists. Keywords: Cochlear implant, speech perception, spatial perception, hearing quality

Beyond Recognition: Visual Contributions to Verbal Working Memory

Purpose: It is well recognized that adding the visual to the acoustic speech signal improves recognition when the acoustic signal is degraded, but how that visual signal affects postrecognition processes is not so well understood. This study was designed to further elucidate the relationships among auditory and visual codes in working memory, a postrecognition process. Design: In a main experiment, 80 young adults with normal hearing were tested using an immediate serial recall paradigm. Three types of signals were presented (unprocessed speech, vocoded speech, and environmental sounds) in three conditions (audio-only, audio–video with dynamic visual signals, and audio–picture with static visual signals). Three dependent measures were analyzed: (a) magnitude of the recency effect, (b) overall recall accuracy, and (c) response times, to assess cognitive effort. In a follow-up experiment, 30 young adults with normal hearing were tested largely using the same procedures, but with a slight change in order of stimulus presentation. Results: The main experiment produced three major findings: (a) unprocessed speech evoked a recency effect of consistent magnitude across conditions; vocoded speech evoked a recency effect of similar magnitude to unprocessed speech only with dynamic visual (lipread) signals; environmental sounds never showed a recency effect. (b) Dynamic and static visual signals enhanced overall recall accuracy to a similar extent, and this enhancement was greater for vocoded speech and environmental sounds than for unprocessed speech. (c) All visual signals reduced cognitive load, except for dynamic visual signals with environmental sounds. The follow-up experiment revealed that dynamic visual (lipread) signals exerted their effect on the vocoded stimuli by enhancing phonological quality. Conclusions: Acoustic and visual signals can combine to enhance working memory operations, but the source of these effects differs for phonological and nonphonological signals. Nonetheless, visual information can support better postrecognition processes for patients with hearing loss.

Item Response Theory Investigation of Misophonia Auditory Triggers

Misophonia is characterised by a low tolerance for day-to-day sounds, causing intense negative affect. This study conducts an in-depth investigation of 35 misophonia triggers. A sample of 613 individuals who identify as experiencing misophonia and 202 individuals from the general population completed self-report measures. Using contemporary psychometric methods, we studied the triggers in terms of internal consistency, stability in time, precision, severity, discrimination ability, and information. Three dimensions of sensitivity were identified, namely, to eating sounds, to nose/throat sounds, and to general environmental sounds. The most informative and discriminative triggers belonged to the eating sounds. Participants identifying with having misophonia had also significantly increased odds to endorse eating sounds as auditory triggers than others. This study highlights the central role of eating sounds in this phenomenon and finds that different triggers are endorsed by those with more severe sound sensitivities than those with low sensitivity.

Application of loudness level to temporally varying sounds

Most of the environmental noises are temporally varying and include various frequency components. Various methods for evaluating the environmental noises have been proposed. Among them, the method for calculating loudness level was first standardized in 1975 as ISO 532, including Stevens' and Zwicker's methods. Unfortunately, these methods can only be applied to steady state sounds. On the other hand, Aeq (Equivalent Continuous A-weight Sound Pressure Level) is standardized for the evaluation of level fluctuating environmental sounds as ISO 1996. In , the energy mean and A-weighting are used for averaging temporal fluctuation and frequency weighting, respectively. The present authors with their colleagues have conducted many psychological experiments using artificial sounds and actual sounds since 1970's and have being introduced that p (Loudness-based Method), which is a combination of ISO 532 for frequency weighting and ISO 1996 for temporal level fluctuation, is a good method for evaluating various kinds of environmental sounds. ISO 532-1 (Zwicker's method) has been revised including the temporal fluctuation into consideration in 2017, in which p has been adopted as a note. The merit of p will be introduced in this paper presenting many examples.