The purpose of this study was to compare and contrast within and between participant performance on three different measures of listening effort: a dual-task paradigm, pupillometry, and skin conductance; participants also subjectively rated the difficulty of their experience. A repeated measures design was used to address the reliability and validity of each measure. 20 participants were recruited and attended two sessions; the second occurred a minimum of one week after the first. Participants listened to sentences presented in stationary noise at four different signal-to-noise ratios: quiet, 0, -3, and -5 dB SNR. The variables of interest were: change in peak-to-peak pupil diameter, change in reaction time from baseline, skin conductance response amplitude, and skin conductance response quantity. The results indicated that as SNR decreased, speech perception performance decreased and subjective listening effort increased. Participants accurately and consistently rated the more difficult conditions as requiring more listening effort. The change in reaction time from baseline, peak-to-peak pupil diameter, and skin conductance response quantity increased as SNR decreased; skin conductance response amplitude did not vary as task difficulty increased, but skin conductance response amplitude was larger for incorrect responses than it was for correct responses. There was a significant practice effect observed for the reaction time data. The dual-task paradigm and pupillometry measures had the greatest reliability and validity. This study demonstrated that listening effort can successfully be quantified both subjectively and objectively by using a variety of tasks. Future studies may be able to use these measures to further assess listening effort in the clinic and in the real-world.

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Purpose: Hearing loss is a prevalent condition among older adults. Structural changes at the auditory periphery, changes in central audition and cognitive function are all known to influence speech understanding in older adults. Biological aging also alters speech and voice characteristics from the age of 50 years. These changes are likely to reduce the clarity of speech signals received by older adults with age-related hearing loss. Recent findings suggest that older adults with hearing loss subjectively find listening to the speech of other older adults more effortful than listening to the speech of younger adults. However, the observations of listener effort were subjective and follow up using an objective measure was recommended. Therefore, the purpose of this study was to determine the influence of speaker age (young versus older) on speech understanding and listener effort in older adults with hearing loss. In addition, the relationships between these parameters, and age and working memory was investigated. It is hypothesised that older adults with hearing loss will recognise less speech, and expend more effort, while listening to speech of an older adult relative to a younger adult. Method: A dual task paradigm was used to measure speech understanding and listening effort in 18 older adult listeners with hearing loss. The primary task involved recognition of target words in sentences containing either high or low contextual cues. The secondary task required listeners to memorise the target words for later recall following a set length of sentences. Listeners performed speech understanding (primary task) under six experimental conditions: For each speaker (i.e., older adult and younger adult) there were 3 listening backgrounds: quiet, and noise at 0 dB SNR and +5 dB SNR. Results: Speech understanding in older adults with hearing loss was significantly improved when the speaker was an older adult, especially in noise. The ability to recall words from memory was also significantly better when the speaker was an older adult. Age was strongly correlated with speech understanding with contributions from hearing loss. Age and working memory had moderate correlations with word recall. Conclusion: The findings provide further evidence that peripheral hearing loss is not the only contributor to speech understanding and word recall ability in older adults. The naturally occurring speech signal also has the potential to influence speech understanding and listening effort in older adults.

Previous research regarding the utility of non-linear frequency compression in hearing aids has revealed conflicting results for speech recognition, marked by high individual variability. The aims of the study were to determine the effect of non-linear frequency compression on aided speech recognition in noise and listening effort using a dual-task test paradigm and to determine if listener variables of hearing loss slope, working memory capacity, and age predicted performance with non-linear frequency compression. 17 older adults with symmetrical sensorineural hearing loss were tested in the sound field using hearing aids. Speech recognition in noise and listening effort were measured by adapting the Revised Speech in Noise Test into recognition/recall dual-task paradigm. On average, speech recognition in noise performance significantly improved with the use of non-linear frequency compression. Individuals with steeply sloping hearing loss received more recognition benefit. Recall performance also significantly improved at the group level with non-linear frequency compression revealing reduced listening effort. Older participants within the study cohort received less recall benefit than the younger participants. Evidence supports individualized selection of non-linear frequency compression, with results suggesting benefits in speech recognition for individuals with steeply sloping hearing losses and in listening effort for younger individuals.

Yes / Knowledge of the underlying mechanisms of effortful listening could help to reduce cases of social withdrawal and mitigate fatigue, especially in older adults. However, the relationship between transient effort and longer-term fatigue is likely to be more complex than originally thought. Here, we manipulated the presence/absence of monetary reward to examine the role of motivation and mood state in governing changes in perceived effort and fatigue from listening. In an online study, 185 participants were randomly assigned to either a ‘reward’ (n = 91) or ‘no-reward’ (n = 94) group and completed a dichotic listening task along with a series of questionnaires assessing changes over time in perceived effort, mood, and fatigue. Effort ratings were higher overall in the reward group, yet fatigue ratings in that group showed a shallower linear increase over time. Mediation analysis revealed an indirect effect of reward on fatigue ratings via perceived mood state; reward induced a more positive mood state which was associated with reduced fatigue. These results suggest that: (a) listening conditions rated as more ‘effortful’ may be less fatiguing if the effort is deemed worthwhile, and (b) alterations to one’s mood state represents a potential mechanism by which fatigue may be elicited during unrewarding listening situations.

Many companies implemented remote work procedures during the pandemic and for many organizations video meetings have since remained a staple. Remote working has enabled employees to be more flexible with their schedules and technical solutions such as live captioning has been identified as potentially enabling deaf/hard-of-hearing employees during meetings. However with new procedures comes concern about how we potentially can be affected by the changes. Some earlier research has shown that speech intelligibility can be improved by the inclusion of text support, but they also raised the possibility that it could have unwanted adverse effects on cognitive abilities (Zhong, Noud et al., 2022). This study was conducted with this focus, studying the effects of text support on specifically listening effort and comprehension during normal as well as adverse conditions (featuring added noise). To investigate the effects of text support a 2 (Noise, No Noise) x 2 (Text Support, No Text Support) design was used. The participants were shown 16 short videos simulating video meetings and after each video were asked to rate their perceived listening effort as well as a comprehension question about the contents of the discussion. Each of the four conditions were equally represented but the order of the specific video files and conditions that applied were randomised for each participant to mitigate undue effects. The results of the study indicate that the presence of captions decrease effort and raise comprehension in both normal and adverse conditions. Noise was found to strongly effect the listening effort required by participants but no significant effect was found upon comprehension. Some concerns regarding the ecological validity were identified during the course of the study such as only studying energetic noise and unrealistic presentation of captions. However the results are nonetheless believed to be generalizable in most regards and showcase that captions can have a positive influence during video meetings.

Purpose: To investigate the effects of speaker age, speaker gender, semantic context, signal-to-noise ratio (SNR) and a listener’s hearing status on speech recognition and listening effort in older adults. We examined the hypothesis that older adults would recognize less speech and exert greater listening effort when listening to the speech of younger versus older adult speakers. Method: Speech stimuli were recorded from 12 adult speakers classified as “younger” (three males and three females aged 18-31 years) and “older” (three males and three females aged 69-89) respectively. A computer-based subjective rating was conducted to confirm that the speakers were representative of younger and older speakers. Listeners included 20 older adults (aged 65 years and above), who were divided into two age-matched groups with and without hearing loss. All listening and speaking participants in the study were native speakers of New Zealand English. A dual-task paradigm was used to measure speech recognition and listening effort; the primary task involved recognition of target words in sentences containing either high or low contextual cues, while the secondary task required listeners to memorise the target words for later recall, following a set number of sentences. Listening tasks were performed with a variety of listening conditions (quiet, +5 dB SNR and 0dB SNR). Results: There were no overall differences in speech recognition scores or word recall scores for the 20 older listeners, when listening to the speech of the younger versus older speakers. However, differential effects of speaker group were observed in the two semantic context conditions (high versus low context). Older male speakers were the easiest to understand when semantic context was low; however, for sentences with high semantic context, the older male group were the most difficult to understand. Word recall scores were also significantly higher in the most challenging listening condition (low semantic context, 0 dB SNR), when the speaker was an older male. Conclusion: Differential effects of speaker group were observed in the two semantic context conditions (high versus low context) suggesting that different speech cues were used by listeners, as the level of context varied. The findings provide further evidence that, in challenging listening conditions, older listeners are able to use a wide range of cues, such as prosodic features and semantic context to compensate for a degraded signal. The availability of these cues depends on characteristics of the speaker, such as rate of speech and prosody, as well as characteristics of the listener and the listening environment. .

Hearing loss has a negative effect on the daily life of 10-15% of the world’s population. One of the most common ways to treat a hearing loss is to fit hearing aids which increases audibility by providing amplification. Hearing aids thus improve speech reception in quiet, but listening in noise is nevertheless often difficult and stressful. Individual differences in cognitive capacity have been shown to be linked to differences in speech recognition performance in noise. An individual’s cognitive capacity is limited and is gradually consumed by increasing demands when listening in noise. Thus, fewer cognitive resources are left to interpret and process the information conveyed by the speech. Listening effort can therefore be explained by the amount of cognitive resources occupied with speech recognition. A well fitted hearing aid improves speech reception and leads to less listening effort, therefore an objective measure of listening effort would be a useful tool in the hearing aid fitting process. In this thesis the Auditory Inference Span Test (AIST) was developed to assess listening effort by measuring an individual’s cognitive spare capacity, the remaining cognitive resources available to interpret and encode linguistic content of incoming speech input while speech understanding takes place. The AIST is a dual-task hearing-innoise test, combining auditory and memory processing, and requires executive processing of speech at different memory load levels. The AIST was administered to young adults with normal hearing and older adults with hearing impairment. The aims were 1) to develop the AIST; 2) to investigate how different signal-to-noise ratios (SNRs) affect memory performance for perceived speech; 3) to explore if this performance would interact with cognitive capacity; 4) to test if different background noise types would interact differently with memory performance for young adults with normal hearing; and 5) to examine if these relationships would generalize to older adults with hearing impairment. The AIST is a new test of cognitive spare capacity which uses existing speech material that is available in several countries, and manipulates simultaneously cognitive load and SNR. Thus, the design of AIST pinpoints potential interactions between auditory and cognitive factors. The main finding of this thesis was the interaction between noise type and SNR showing that decreased SNR reduced cognitive spare capacity more in speech-like noise compared to speech-shaped noise, even though speech intelligibility levels were similar between noise types. This finding applied to young adults with normal hearing but there was a similar effect for older adults with hearing impairment with the addition of background noise compared to no background noise. Task demands, MLLs, interacted with cognitive capacity, thus, individuals with less cognitive capacity were more sensitive to increased cognitive load. However, MLLs did not interact with noise type or with SNR, which shows that different memory load levels were not affected differently in different noise types or in different SNRs. This suggests that different cognitive mechanisms come into play for storage and processing of speech information in AIST and for listening to speech in noise. Thus, the results suggested that a test of cognitive spare capacity seems to be a useful way to assess listening effort, even though the AIST, in the design used in this thesis, might be too cognitively demanding to provide reliable results for all individuals.

No description available.

Listening ability is affected by external factors such as background noise and internal factors such as attention-allocation. I varied listening conditions and cognitive load and evaluated auditory word recognition and ratings of listening effort. Additionally, I investigated how individual differences in working memory capacity affected word recognition, recall, listening effort, and how working memory capacity interacted with other factors. Rönnberg et al.’s (2013) Ease of Language Understanding (ELU) model states that individual differences in working memory capacity will lead to differences in language comprehension in challenging listening conditions, where those with higher working memory capacity will be better at speech recognition. Using a dual-task experiment, participants heard and repeated words presented in three listening conditions: masked with pink noise, masked with babble, and processed through a hearing loss simulator. To manipulate cognitive load, participants completed the speech recognition task in both single- and dual-task paradigms. In the dual-task paradigm, participants continuously tracked a pseudo-randomly moving target on a screen for half the experiment. Participants reported perceived listening effort for each combination of listening condition and tracking condition. Additionally, memory for correctly heard words was tested with a recognition memory test. Word recognition performance and listening effort rating data agreed with my hypotheses that difficult listening conditions would produce poorer word recognition performance and increased listening effort. Interesting effects of cognitive load are discussed. The relation between working memory capacity and performance on various measures is also discussed in the context of the ELU model and theories of working memory capacity. Internal and external factors clearly interact to affect listening, and this interaction varies across individuals. / Thesis / Master of Science (MSc) / The ability to hear is affected by many factors, including attention and memory. The goal of this research is to investigate the cognitive factors (attention and memory) that affect hearing and how these effects differ on an individual level. My findings contribute to a better understanding of how background noise and mental demand affect hearing ability and listening effort, as well as how individual differences in cognitive ability further influence these factors. Results suggest that background noise and increased mental demand will decrease listening ability and increase listening effort. These changes in listening differ according to individual cognitive ability.