Real-world listening effort in adult cochlear implant users

Cochlear implants (CI) are a treatment to provide a sense of hearing to individuals with severe-to-profound sensorineural hearing loss. Even when optimal levels of intelligibility are achieved after cochlear implantation, many CI users complain about the effort required to understand speech in everyday life contexts. This sustained mental exertion, commonly known as “listening effort”, could negatively affect their lives, especially regarding communication, participation, and long-term cognitive health. This thesis aimed to evaluate the listening effort experienced by CI recipients in real-world sound scenarios. The research focused on social listening situations that are particularly common in everyday life such as having conversations in a busy café or communicating through video call. Additionally, some situations that prevailed during the COVID-19 pandemic were also examined (e.g., listening to someone who is wearing a facemask). Multimodal measures of listening effort were employed throughout the research project to obtain a comprehensive assessment. Nonetheless, the primary focus was on measures that quantify objectively the cognitive demands of listening through a CI. To that end, we used a combination of physiological measures, functional near infrared spectroscopy (fNIRS) brain imaging and simultaneous pupillometry, both of which are compatible with CIs and capable of providing insights into the neural underpinnings of effortful listening. We also proposed a novel approach to quantify “listening efficiency”, an integrated behavioural measure that reflects both intelligibility and listening effort. We successfully applied these assessments to 168 CI users and 75 age-matched normally hearing (NH) controls who were recruited throughout the project. We found that CI users experienced high levels of listening effort, even when their intelligibility was optimal under highly favourable listening conditions. Objective measures revealed that CI listeners exhibited significantly inferior listening efficiency than NH controls when listening to speech under moderate levels of cafeteria background noise and when attending online video calls. Physiologically, they showed elevated levels of arousal as revealed by larger and prolonged pupil dilations to baseline compared with NH controls, suggesting high cognitive load and increased need for recovery. The importance of visual cues was evident; the presence of video and captions benefited CI recipients by improving considerably their listening efficiency during online communication. These results were consistent with their subjective ratings of effort, both in the experiments and in daily life. These findings provide objective evidence of the cognitive burden endured by CI listeners in everyday life. In addition, the objective assessments proposed were proved feasible to quantify the performance and cognitive demands of listening through a CI. In particular, listening efficiency showed sensitivity to differences in task demands and between groups, even when intelligibility remained near perfect. We argue that listening efficiency holds potential to become a CI outcome measure

Real-world listening effort in adult cochlear implant users

Cochlear implants (CI) are a treatment to provide a sense of hearing to individuals with severe-to-profound sensorineural hearing loss. Even when optimal levels of intelligibility are achieved after cochlear implantation, many CI users complain about the effort required to understand speech in everyday life contexts. This sustained mental exertion, commonly known as “listening effort”, could negatively affect their lives, especially regarding communication, participation, and long-term cognitive health. This thesis aimed to evaluate the listening effort experienced by CI recipients in real-world sound scenarios. The research focused on social listening situations that are particularly common in everyday life such as having conversations in a busy café or communicating through video call. Additionally, some situations that prevailed during the COVID-19 pandemic were also examined (e.g., listening to someone who is wearing a facemask). Multimodal measures of listening effort were employed throughout the research project to obtain a comprehensive assessment. Nonetheless, the primary focus was on measures that quantify objectively the cognitive demands of listening through a CI. To that end, we used a combination of physiological measures, functional near infrared spectroscopy (fNIRS) brain imaging and simultaneous pupillometry, both of which are compatible with CIs and capable of providing insights into the neural underpinnings of effortful listening. We also proposed a novel approach to quantify “listening efficiency”, an integrated behavioural measure that reflects both intelligibility and listening effort. We successfully applied these assessments to 168 CI users and 75 age-matched normally hearing (NH) controls who were recruited throughout the project. We found that CI users experienced high levels of listening effort, even when their intelligibility was optimal under highly favourable listening conditions. Objective measures revealed that CI listeners exhibited significantly inferior listening efficiency than NH controls when listening to speech under moderate levels of cafeteria background noise and when attending online video calls. Physiologically, they showed elevated levels of arousal as revealed by larger and prolonged pupil dilations to baseline compared with NH controls, suggesting high cognitive load and increased need for recovery. The importance of visual cues was evident; the presence of video and captions benefited CI recipients by improving considerably their listening efficiency during online communication. These results were consistent with their subjective ratings of effort, both in the experiments and in daily life. These findings provide objective evidence of the cognitive burden endured by CI listeners in everyday life. In addition, the objective assessments proposed were proved feasible to quantify the performance and cognitive demands of listening through a CI. In particular, listening efficiency showed sensitivity to differences in task demands and between groups, even when intelligibility remained near perfect. We argue that listening efficiency holds potential to become a CI outcome measure

Hearing Loss and Driving: Does Auditory Distraction Have a Disproportionate Effect on the Hearing Impaired?

Research showing differences between the driving outcomes of hearing impaired and normally hearing individuals (such as raised road traffic accidents), proposes this has occurred due to two main reasons: (1) that sound present in the driving environment is inaudible for hearing impaired drivers, and (2) that audible sound is disproportionately distracting for the hearing impaired driver. This thesis reports on a series of experiments which investigated the latter of these proposals. A questionnaire study was used to explore driving patterns and experiences of hearing impaired individuals. Empirical studies were also conducted to investigate the effect of hearing loss on driving performance and visual attention, under auditory task conditions. Questionnaire responses suggested that hearing impaired individuals did not perceive hearing loss as problematic for driving performance. However, the self-reported hearing of respondents predicted reports of driving difficulty better than any other independent variable. A laboratory-based study hinted that extra visual task performance decrements as a result of auditory engagement occurred in hearing impaired individuals. Since these findings were in older adults, the influence of factors co-existing with hearing loss (such as cognitive decline) were questioned. These confounds were removed by presenting an auditory task subject to simulated hearing loss in a dual-task driving simulator experiment; allowing for a young, normally hearing sample, and within-subjects design. The resulting data showed no disproportionate effect of hearing loss on driving performance during the concurrent auditory task. Accordingly, distortion to sound arising from hearing loss may not be entirely responsible for the disproportionate effects of auditory distraction in hearing impaired drivers. Other factors, co-existing with hearing loss, appear to act synergistically to cause problems. Future work should investigate further the aspects of hearing loss (and co-existing factors) responsible for changes in driving outcomes, by, for instance, using a group of young hearing impaired participants

Verbal comprehension after brain damage :a psycholinguistic investigation with special reference to cerebro-vascular accident

PhD ThesisA review of theory and practice in the examination of verbal comprehension in brain-dairiaged adults leads to the conclusion that this underdeveloped area of study can benefit from the application of theories from linguistics. An experimental investigation of (principally) adults who had suffered cerebro -vascular accident applied, amoxigst other linguistic theories, the division of language into phonological, syntactic and semantic levels of organization. The main findings were: a) Semantic abilities in speech and comprehension corresponded; syntactic abilities in speech corresponded with those in reading comprehension, but not aural comprehension; comprehension of phonemic distinctions corresponded with phonetic articulatory abilities, but not with degree of phonemic paraphasia. Tests of verbal comprehension which required simple manipulations of-objects or tokens were contaminated by gesture dyspraxia. Functional comprehension was not a reliable predictor of results on linguistic tests. b) Piphasic adults with left-brain damage experienced significantly more difficulties in comprehension when sequence was critical to the meaning of a word or sentence. At the syntactic level this occurred with reading as well as with aural input, indicating a central difficulty rather than one which is modality-specific. in aural comprehension, unlike all types of control subjects including children, aphasic adults found sentences with reversible elements in surface structure harder than sentences in which reversible deep relations are not made explicit in surface structure sequence. Sequencing appears to be a significant influence on verbal comprehension after left-brain damage. c) Right-brain-damaged adults who were not aphasic in speech, and who were familial right-handers, were selectively impaired in semantic comprehension. Semantic comprehension may be bilaterally represented in the brain, although comprehension at syntactic and phonological levels may depend principally on mechanisms lateralized to the left hemisphere.Ridley Fellowship, Newcastle University

Clemson Graduate School Catalog, 1987-1988

https://tigerprints.clemson.edu/grad_anncmnt/1002/thumbnail.jp

Proceedings of the 19th Sound and Music Computing Conference

Proceedings of the 19th Sound and Music Computing Conference - June 5-12, 2022 - Saint-Étienne (France). https://smc22.grame.f