Listening Effort Bimodal hearing

  • Research type

    Research Study

  • Full title

    Investigating the effect of bimodal aiding on listening effort in unilateral cochlear-implant users

  • IRAS ID

    277181

  • Contact name

    Ian M. Wiggins

  • Contact email

    Ian.Wiggins@nottingham.ac.uk

  • Sponsor organisation

    University of Nottingham

  • Clinicaltrials.gov Identifier

    000, 000

  • Duration of Study in the UK

    1 years, 6 months, 29 days

  • Research summary

    Research Summary

    Cochlear-implant users experience high levels of listening effort(LE) and fatigue in everyday life, with negative consequences for communication, participation, and long-term cognitive health. Even when they are able to achieve near-ceiling levels of performance regarding intelligibility, CI users still report that listening in noisy environments is an effortful task that demands a high degree of mental exertion.

    Recent studies has suggested, that bimodal aiding, wearing a contralateral HA alongside the CI, could provide benefits for reducing LE.

    However, there is a large inter-subject variability regarding bimodal benefits which is not fully understood and leads to low rates of hearing aid use in CI recipients. Further research is needed to improve our understanding of the potential benefits regarding listening effort that bimodal aiding can provide. This is particularly essential now that the inclusion criteria for receiving a CI has been expanded (TA566), including candidates with profound and severe HL (hearing threshold ≥80 dB HL). This change in the candidacy criteria will increase considerably the current trend of recipients that present residual hearing in the non-implanted ear and therefore will be more likely to benefit from a contralateral HA alongside the CI.

    As shown by our previous studies, the combination of functional near-infrared spectroscopy (fNIRS) and pupillometry can be used as physiological measures to investigate the brain activity that underlies effortful listening in the implanted population.Both techniques are non-invasive, acoustically quiet and fully compatible with CIs, which make them highly appropriate to investigate the neural underpinnings of listening effort in CI recipients.

    This study aims to employ both techniques to assess the effects of bimodal aiding regarding listening effort in CI users. Objective measures of such effects will improve our understanding of the inter-subject variability and can potentially predict in advance which users are more likely to get benefits from bimodal aiding.

    Summary of Results

    During the COVID-19 pandemic, global society has experienced a rapid replacement of in-person interactions by remote communication. While online communication tools hold potential to improve accessibility, previous studies have suggested that the increased reliance on remote communication during the pandemic posed additional communication challenges to people with hearing loss, including cochlear-implant (CI) users. This study aimed to investigate which technological features make online communication easier (i.e., less cognitively demanding) for CI users.

    Fifty adult CI users and fifty approximately age-matched normally-hearing (NH) controls participated in an online test. First, participants viewed examples of pre-recorded online conversations, switching at will between three presentation modes: audio only, video (audio-visual), and video plus captions. Participants were asked which presentation mode they would have preferred had each conversation been a real video call that they were involved in, and why. Subsequently, participants performed a behavioural test of speech recognition under the same three presentation modes. Both accuracy and response time were recorded during the task.

    Most CI users selected the “video plus caption” mode in the preference task, whereas NH controls overall preferred the “video” mode. CI users commented that the captions made it easier to follow the conversation, by providing confirmation of what was heard and a back-up in case of missed words. Conversely, NH participants found captions distracting and not needed, preferring regular audio-visual presentation. Performance in the behavioural task mirrored the subjective preferences. Based on a joint analysis of accuracy and response time, CI users benefitted significantly from the addition of visual cues, and again from the addition of captions. NH controls, in contrast, achieved similar performance regardless of presentation mode. Even with captions, CI users’ performance remained significantly below that achieved by NH controls in all presentation modes.

    In conclusion, online communication is more cognitively demanding for CI users than for their NH peers, manifested as slower and less accurate responses to what they have heard. However, CI users benefit significantly from the addition of visual cues (i.e., being able to see the talker’s face) and benefit further from the addition of captions. We propose that online communication platforms should make these features available and adjustable according to individual need and preference.

  • REC name

    North West - Greater Manchester Central Research Ethics Committee

  • REC reference

    20/NW/0141

  • Date of REC Opinion

    28 Apr 2020

  • REC opinion

    Further Information Favourable Opinion