Uses of Linguistic Context in Speech Listening: Does Acquired Hearing Loss Lead to Reduced Engagement of Prediction?

Research investigating the complex interplay of cognitive mechanisms involved in speech listening for people with hearing loss has been gaining prominence. In particular, linguistic context allows the use of several cognitive mechanisms that are not well distinguished in hearing science, namely those relating to "postdiction", "integration", and "prediction". We offer the perspective that an unacknowledged impact of hearing loss is the differential use of predictive mechanisms relative to age-matched individuals with normal hearing. As evidence, we first review how degraded auditory input leads to reduced prediction in people with normal hearing, then consider the literature exploring context use in people with acquired postlingual hearing loss. We argue that no research on hearing loss has directly assessed prediction. Because current interventions for hearing do not fully alleviate difficulty in conversation, and avoidance of spoken social interaction may be a mediator between hearing loss and cognitive decline, this perspective could lead to greater understanding of cognitive effects of hearing loss and provide insight regarding new targets for intervention.

A qualitative investigation of the hearing and hearing-aid related emotional states experienced by adults with hearing loss.

OBJECTIVE: Despite previous research into the psychosocial impact of hearing loss, little detail is known regarding the hearing and hearing-aid-related emotional states experienced by adults with hearing loss in everyday life, and how they occur. DESIGN: Individual remote semi-structured interviews were audio-recorded, transcribed verbatim and qualitatively analysed with reflexive and inductive thematic analysis. STUDY SAMPLE: Seventeen participants (9 female) with hearing loss (age range 44-74 years) participated. Ten used bilateral hearing aids, four unilateral and three used no hearing aids at the time of interviews. RESULTS: The four main themes which emerged from the data were: identity and self-image, autonomy and control, personality and dominant emotional states and situational cost/benefit analysis with respect to use of hearing aids. CONCLUSIONS: This study goes beyond previous literature by providing a more detailed insight into emotions related to hearing and hearing-aids in adults. Hearing loss causes a multitude of negative emotions, while hearing aids generally reduce negative emotions and allow for more positive emotions. However, factors such as lifestyle, personality, situational control, the relationship with those in conversation and the attribution of blame are key to individual emotional experience. Clinical implications include the important role of social relationships in assessment and counselling.

Conversation success in one-to-one and group conversation: a group concept mapping study of adults with normal and impaired hearing.

OBJECTIVE: The concept of conversation success is undefined, although prior work has variously related it to accurate exchange of information, alignment between interlocutors, and good management of misunderstandings. This study aimed (1) to identify factors of conversation success and (2) to explore the importance of these factors in one-to-one versus group conversations. DESIGN: Group concept mapping method was applied. Participants responded to two brainstorming prompts ("What does 'successful conversation' look like?" and "Think about a successful conversation you have taken part in. What aspects of that conversation contributed to its success?"). The resulting statements were sorted into related clusters and rated in importance for one-to-one and group conversation. STUDY SAMPLE: Thirty-five adults with normal and impaired hearing. RESULTS: Seven clusters were identified: (1) Being able to listen easily; (2) Being spoken to in a helpful way; (3) Being engaged and accepted; (4) Sharing information as desired; (5) Perceiving flowing and balanced interaction; (6) Feeling positive emotions; (7) Not having to engage coping mechanisms. Three clusters (1, 2, and 4) were more important in group than in one-to-one conversation. There were no differences by hearing group. CONCLUSIONS: These findings emphasise that conversation success is a multifaceted concept.

Changes in Orientation Behavior due to Extended High-Frequency (5 to 10 kHz) Spatial Cues.

OBJECTIVES: Current hearing aids have a limited bandwidth, which limits the intelligibility and quality of their output, and inhibits their uptake. Recent advances in signal processing, as well as novel methods of transduction, allow for a greater useable frequency range. Previous studies have shown a benefit for this extended bandwidth in consonant recognition, talker-sex identification, and separating sound sources. To explore whether there would be any direct spatial benefits to extending bandwidth, we used a dynamic localization method in a realistic situation. DESIGN: Twenty-eight adult participants with minimal hearing loss reoriented themselves as quickly and accurately as comfortable to a new, off-axis near-field talker continuing a story in a background of far-field talkers of the same overall level in a simulated large room with common building materials. All stimuli were low-pass filtered at either 5 or 10 kHz on each trial. To further simulate current hearing aids, participants wore microphones above the pinnae and insert earphones adjusted to provide a linear, zero-gain response. RESULTS: Each individual trajectory was recorded with infra-red motion-tracking and analyzed for accuracy, duration, start time, peak velocity, peak velocity time, complexity, reversals, and misorientations. Results across listeners showed a significant increase in peak velocity and significant decrease in start and peak velocity time with greater (10 kHz) bandwidth. CONCLUSIONS: These earlier, swifter orientations demonstrate spatial benefits beyond static localization accuracy in plausible conditions; extended bandwidth without pinna cues provided more salient cues in a realistic mixture of talkers.

Dementia and hearing-aid use: a two-way street.

OBJECTIVES: Hearing-aid use may reduce risk of dementia, but cognitive impairment makes use more challenging. An observed association between reduced hearing-aid use and incident dementia could reflect either or both of these causal paths. The objective was to examine the effects of each path while minimising contamination between paths. METHODS: Health records data from 380,794 Veterans who obtained hearing aids from the US Veterans Affairs healthcare system were analysed. Analysis 1 (n = 72,180) used multivariable logistic regression to model the likelihood of incident dementia 3.5-5 years post hearing-aid fitting for patients free of dementia and mild cognitive impairment (MCI). Analysis 2 (n = 272,748) modelled the likelihood of being a persistent hearing-aid user at 3 years 2 months after fitting, contrasting subgroups by level of cognitive function at the time of fitting. Analysis time windows were optimized relative to dataset constraints. Models were controlled for available relevant predictors. RESULTS: The adjusted OR for incident dementia was 0.73 (95% CI 0.66-0.81) for persistent (versus non-persistent) hearing-aid users. The adjusted OR for hearing-aid use persistence was 0.46 (95% CI 0.43-0.48) in those with pre-existing dementia (versus those remaining free of MCI and dementia). CONCLUSION: Substantial independent associations are observed in both directions, suggesting that hearing-aid use decreases risk of dementia and that better cognitive function predisposes towards persistent use. Research studying protective effects of hearing-aid use against dementia needs to account for cognitive status. Clinically, hearing devices and hearing care processes must be accessible and usable for all, regardless of their cognitive status.

The effect of stimulus duration on preferences for gain adjustments when listening to speech.

OBJECTIVES: In the personalisation of hearing-aid fittings, gain is often adjusted to suit patient preferences using live speech. When using brief sentences as stimuli, the minimum gain adjustments necessary to elicit consistent preferences ("preference thresholds") were previously found to be much greater than typical adjustments in current practice. The current study examined the role of duration on preference thresholds. DESIGN: Participants heard 2, 4 and 6-s segments of a continuous monologue presented successively in pairs. The first segment of each pair was presented at each individual's real-ear or prescribed gain. The second segment was presented with a ±0-12 dB gain adjustment in one of three frequency bands. Participants judged whether the second was "better", "worse" or "no different" from the first. STUDY SAMPLE: Twenty-nine adults, all with hearing-aid experience. RESULTS: The minimum gain adjustments needed to elicit "better" or "worse" judgments decreased with increasing duration for most adjustments. Inter-participant agreement and intra-participant reliability increased with increasing duration up to 4 s, then remained stable. CONCLUSIONS: Providing longer stimuli improves the likelihood of patients providing reliable judgments of hearing-aid gain adjustments, but the effect is limited, and alternative fitting methods may be more viable for effective hearing-aid personalisation.

The Effect of Hearing Loss and Hearing Device Fitting on Fatigue in Adults: A Systematic Review.

OBJECTIVES: To conduct a systematic review to address two research questions: (Q1) Does hearing loss have an effect on fatigue? (Q2) Does hearing device fitting have an effect on fatigue? It was hypothesized that hearing loss would increase fatigue (H1), and hearing device fitting would reduce fatigue (H2). DESIGN: Systematic searches were undertaken of five bibliographic databases: Embase, MedLine, Web of Science, Psychinfo, and the Cochrane Library. English language peer-reviewed research articles were included from inception until present. Inclusion and exclusion criteria were formulated using the Population, Intervention, Comparison, Outcomes and Study design strategy. RESULTS: Initial searches for both research questions produced 1,227 unique articles, after removal of duplicates. After screening, the full text of 61 studies was checked, resulting in 12 articles with content relevant to the research questions. The reference lists of these studies were examined, and a final updated search was conducted on October 16, 2019. This resulted in a final total of 20 studies being selected for the review. For each study, the information relating to the Population, Intervention, Comparison, Outcomes and Study design criteria and the statistical outcomes relating to both questions (Q1 and Q2) were extracted. Evidence relating to Q1 was provided by 15 studies, reporting 24 findings. Evidence relating to Q2 was provided by six studies, reporting eight findings. One study provided evidence for both. Using the Grading of Recommendations Assessment, Development and Evaluation guidelines, the quality of evidence on both research questions was deemed to be "very low." It was impossible to perform a meta-analysis of the results due to a lack of homogeneity. CONCLUSIONS: As the studies were too heterogeneous to support a meta-analysis, it was not possible to provide statistically significant evidence to support the hypotheses that hearing loss results in increased fatigue (H1) or that hearing device fitting results in decreased fatigue (H2). Despite this, the comparative volume of positive results and the lack of any negative findings are promising for future research (particularly in respect of Q1). There was a very small number of studies deemed eligible for the review, and there was large variability between studies in terms of population, and quantification of hearing loss and fatigue. The review highlights the need for consistency when measuring fatigue, particularly when using self-report questionnaires, where the majority of the current evidence was generated.

A Measure of Long-Term Hearing Aid Use Persistence Based on Battery Reordering Data.

OBJECTIVE: We describe the construction of a hearing aid long-term use persistence measure based on battery reorder data. The measure is derived from the notion that hearing aid users keep using their devices for some time after placing a battery order. DESIGN: A hearing aid user is defined as persistent at time T if they placed a battery order within a time span W preceding T. We characterize and validate this measure using electronic health records from a large sample of US Veterans. RESULTS: We describe how to choose parameters T and W for calculating persistence rates in the patient sample. For validation, the associations of persistence with: (1) the duration over which users received outpatient hearing aid care; (2) self-reported hearing aid use shortly after fitting; and (3) patient age and hearing loss are investigated. In all cases, plausible dependencies are observed. CONCLUSIONS: We conclude that our persistence measure is viable and hope this will motivate its use in similar studies.

Electronic Health Records As a Platform for Audiological Research: Data Validity, Patient Characteristics, and Hearing-Aid Use Persistence Among 731,213 U.S. Veterans.

OBJECTIVES: This article presents a summary of audiological, general health, and hearing aid (HA) outcome data in a large sample of U.S. Veterans receiving HAs. The current article also provides the foundation for a series of papers that will explore relationships between a wide range of factors and HA outcomes. DESIGN: The patient sample is all (n = 731,213) patients for whom HAs were ordered between April 2012 and October 2014 through the U.S. Veterans Health Administration Remote Order Entry System. For these patients, Veterans Affairs electronic health records (EHRs) stored in various databases provided data on demographics, received diagnostic and procedure codes (2007 to 2017), audiometry, self-reported outcomes up to 6 months postfitting, and HA battery orders (to 2017). Data cleaning and preparation was carried out and is discussed with reference to insights that provide potential value to other researchers pursuing similar studies. HA battery order data over time was used to derive a measure of long-term HA use persistence. Descriptive statistics were used to characterize the sample, comparative analyses against other data supported basic validity assessment, and bivariate analyses probed novel associations between patient characteristics and HA use persistence at 2 years postfitting. RESULTS: Following extensive cleaning and data preparation, the data show plausible characteristics on diverse metrics and exhibit adequate validity based on comparisons with other published data. Further, rates of HA use persistence are favorable when compared against therapy persistence data for other major chronic conditions. The data also show that the presence of certain comorbid conditions (Parkinson's disease, diabetes, arthritis, and visual impairment) are associated with significantly lower HA use persistence, as are prior inpatient admissions (especially among new HA recipients), and that increasing levels of multimorbidity, in general, are associated with decreasing HA use persistence. This is all despite the fact that deriving relevant audiological care-process variables from the available records was not straightforward, especially concerning the definition of the date of HA fitting, and the use of battery ordering data to determine long-term HA use persistence. CONCLUSIONS: We have shown that utilizing EHRs in audiology has the potential to provide novel insights into clinical practice patterns, audiologic outcomes, and relations between factors pertaining to hearing and to other health conditions in clinical populations, despite the potential pitfalls regarding the lack of control over the variables available and limitations on how the data are entered. We thus conclude that research using EHRs has the potential to be an integral supplement to population-based and epidemiologic research in the field of audiology.

Can listening-related fatigue influence well-being? Examining associations between hearing loss, fatigue, activity levels and well-being.

OBJECTIVE: Well-being is influenced by the activities we undertake. Hearing loss may reduce well-being directly through increased listening-related fatigue due to cognitive and emotional strain in challenging situations. Hearing loss and hearing device use may also indirectly impact fatigue and well-being by altering the frequency and type of daily-life activities. This review examines the available literature to help understand the relationships. DESIGN: We provide (i) a summary of the extant literature regarding hearing loss, hearing device use and fatigue in adults, as well as regarding fatigue and daily-life activity (work, social and physical) and (ii) a systematic search and narrative review of the relationships between hearing loss, hearing device use and activity. STUDY SAMPLE: The systematic search resulted in 66 eligible texts. RESULTS: Data examining well-being in persons with hearing loss are limited. Our literature review suggests that well-being can be related directly and indirectly to hearing loss, hearing device use, activity level and listening-related fatigue. CONCLUSIONS: Variations and interactions between hearing loss, hearing device use, fatigue and activity levels can be expected to impact well-being in persons with hearing loss in direct and indirect ways. Future research linking hearing and daily-life fatigue should take account of activity levels.

Daily-Life Fatigue in Mild to Moderate Hearing Impairment: An Ecological Momentary Assessment Study.

OBJECTIVES: Previous research has indicated an association between hearing impairment (HI) and daily-life fatigue. However, the temporal and contextual correlates of such fatigue are largely unexplored. The present study used ecological momentary assessment (EMA) to examine (1) whether people with HI are more fatigued than people with normal hearing, (2) whether individuals with HI and normal hearing (NH) show similar diurnal patterns of fatigue, (3) whether people with HI spend less time in challenging listening situations compared with NH controls, and (4) whether more challenging listening situations are associated with more fatigue and whether hearing ability influences any observed association. DESIGN: After excluding 22 participants with self-reported fatiguing health conditions from analyses, the participant sample consisted of 24 adults with HI and 20 adults with NH, aged 44 to 77 years (M = 65.4, SD = 7.5). Data were collected using smartphones and a commercially available EMA app, which ran the specified EMA protocol for this study. Participants responded to six smartphone surveys per day for two weeks. "In-the-moment" questions asked participants to report on their listening situation and to rate their current level of fatigue ("momentary fatigue") at quasi-random time points throughout the day. Data were analyzed using multilevel modeling. RESULTS: Hearing group (HI versus NH) was unrelated to trait, daily, and momentary fatigue; both participants with HI and NH became increasingly fatigued throughout the day and at a similar rate. Challenging listening situations occurred infrequently both for HI and NH groups. Participants with NH were more likely to report that there were people speaking in the background whom they were trying to ignore, but participants with HI were more likely to report a greater number of background speakers. No associations were found between within-person listening situations and momentary fatigue, but person-mean listening activity and conversational status were related to momentary fatigue. Notably, having tinnitus was positively related to momentary fatigue, after controlling for other covariates. Finally, having a fatiguing health condition was a strong predictor of both trait and momentary fatigue. CONCLUSIONS: This is the first study to explore and compare fatigue across HI and NH groups using EMA. Contrary to expectations, the groups showed similar levels and diurnal patterns of fatigue, and fatigue was mostly unrelated to aspects of the listening environment. Between-person differences, although statistically significant, produced small effect sizes and therefore must be accepted cautiously. Issues with group matching, the measurement of fatigue, and perceived hearing-related difficulties among participants with NH are notable limitations. However, this study makes a novel contribution to both EMA and hearing research and demonstrates the importance of screening for fatiguing health conditions. Further research is warranted, particularly with individuals with more severe HI.

Covid-19 Lockdown Affects Hearing Disability and Handicap in Diverse Ways: A Rapid Online Survey Study.

OBJECTIVES: The aim of this study was to explore the perceived effects of coronavirus disease 2019 (Covid-19) social distancing restrictions and safety measures on people with hearing loss. DESIGN: Participants were 129 adults (48.1% female, mean age 64.4 years) with an audiometric hearing loss, living in Glasgow, Scotland. A rapidly deployed 24-item online questionnaire asked about the effects of certain aspects of lockdown, including face masks, social distancing, and video calling, on participants' behavior, emotions, hearing performance, practical issues, and tinnitus. Data were analyzed descriptively across the entire sample, and with Chi-squared tests for differences between subgroups self-reporting relatively good and relatively poor unaided hearing, respectively. Additional free-text responses provided further perspectives. RESULTS: Behavior: Video calls are used more frequently than prelockdown. The better-hearing group use their hearing aids less. Emotions: There is increased anxiety (especially among the worse hearing group) concerning verbal communication situations and access to audiology services, and greater rumination about one's own hearing loss. Enjoyment of group video calls is mixed. The worse hearing group shows substantial relief at not being obliged to attend challenging social gatherings. Across both groups, a majority would like to see all key workers equipped with transparent face masks. Hearing performance: A large majority finds it hard to converse with people in face masks due to muffled sound and lack of speechreading cues, but conversing at a safe distance is not universally problematic. In the worse hearing group, performance in video calls is generally inferior to face-to-face, but similar to telephone calls. Those who use live subtitling in video calls appreciate their value. TV and radio updates about Covid-19 are easy to follow for most respondents. There is only weak evidence of face mask fixtures interfering with hearing aids on the ear, and of tinnitus having worsened during lockdown. CONCLUSIONS: With due regard for the limitations of this rapid study, we find that there are many negative-and a few positive-effects of Covid-19 restrictions and safety measures on people with hearing loss. From a societal perspective, the widespread adoption of clear face masks may alleviate some of the difficulties and anxieties this population experience. From an individual perspective, one may consider using live subtitles on video calls. Manufacturers of hearing devices should consider developing processing modes and accessories specifically designed for video calls. Finally, repair and maintenance services should be resumed as soon as it is safe to do so.

The Quest for Ecological Validity in Hearing Science: What It Is, Why It Matters, and How to Advance It.

Ecological validity is a relatively new concept in hearing science. It has been cited as relevant with increasing frequency in publications over the past 20 years, but without any formal conceptual basis or clear motive. The sixth Eriksholm Workshop was convened to develop a deeper understanding of the concept for the purpose of applying it in hearing research in a consistent and productive manner. Inspired by relevant debate within the field of psychology, and taking into account the World Health Organization's International Classification of Functioning, Disability, and Health framework, the attendees at the workshop reached a consensus on the following definition: "In hearing science, ecological validity refers to the degree to which research findings reflect real-life hearing-related function, activity, or participation." Four broad purposes for striving for greater ecological validity in hearing research were determined: A (Understanding) better understanding the role of hearing in everyday life; B (Development) supporting the development of improved procedures and interventions; C (Assessment) facilitating improved methods for assessing and predicting ability to accomplish real-world tasks; and D (Integration and Individualization) enabling more integrated and individualized care. Discussions considered the effects of variables and phenomena commonly present in hearing-related research on the level of ecological validity of outcomes, supported by examples from a few selected outcome domains and for different types of studies. Illustrated with examples, potential strategies were offered for promoting a high level of ecological validity in a study and for how to evaluate the level of ecological validity of a study. Areas in particular that could benefit from more research to advance ecological validity in hearing science include: (1) understanding the processes of hearing and communication in everyday listening situations, and specifically the factors that make listening difficult in everyday situations; (2) developing new test paradigms that include more than one person (e.g., to encompass the interactive nature of everyday communication) and that are integrative of other factors that interact with hearing in real-life function; (3) integrating new and emerging technologies (e.g., virtual reality) with established test methods; and (4) identifying the key variables and phenomena affecting the level of ecological validity to develop verifiable ways to increase ecological validity and derive a set of benchmarks to strive for.

Hearing impairment and daily-life fatigue: a qualitative study.

Objective: Hearing impairment is linked to increased fatigue, yet little is known about the real-world impact of this fatigue. This qualitative study investigated the experience of daily-life fatigue in people with a hearing impairment. Design: Individual face-to-face semi-structured interviews were conducted. Thematic analysis was then used to analyse the data. Study sample: Fourteen hearing impaired participants (aged 44-70 years) who varied in terms of hearing loss, hearing aid status, age and gender. Results: The themes and sub-themes that emerged from the transcripts were: Fatigue (effort-driven fatigue, emotion-driven fatigue, breaks and recovery, the perceived relationship between hearing impairment and fatigue, and sleep), Effort (cognitive effort and physical effort), Coping Strategies (withdrawal, avoidance and planning), Relationships and Emotions, Hearing Aid Impact. Conclusions: The study highlights that hearing impairment-related fatigue is experienced by many but not all, and to different extents. Hearing aids were weakly linked to a beneficial effect on fatigue. In addition to the more widely researched effort-driven fatigue, participants described fatigue linked to the negative emotions related to having a hearing impairment. These findings, in conjunction with the widespread utilisation of different coping strategies, demonstrate that the experience of fatigue is varied and likely dependent on personal factors and lifestyle.

Relations Between Self-Reported Daily-Life Fatigue, Hearing Status, and Pupil Dilation During a Speech Perception in Noise Task.

OBJECTIVE: People with hearing impairment are likely to experience higher levels of fatigue because of effortful listening in daily communication. This hearing-related fatigue might not only constrain their work performance but also result in withdrawal from major social roles. Therefore, it is important to understand the relationships between fatigue, listening effort, and hearing impairment by examining the evidence from both subjective and objective measurements. The aim of the present study was to investigate these relationships by assessing subjectively measured daily-life fatigue (self-report questionnaires) and objectively measured listening effort (pupillometry) in both normally hearing and hearing-impaired participants. DESIGN: Twenty-seven normally hearing and 19 age-matched participants with hearing impairment were included in this study. Two self-report fatigue questionnaires Need For Recovery and Checklist Individual Strength were given to the participants before the test session to evaluate the subjectively measured daily fatigue. Participants were asked to perform a speech reception threshold test with single-talker masker targeting a 50% correct response criterion. The pupil diameter was recorded during the speech processing, and we used peak pupil dilation (PPD) as the main outcome measure of the pupillometry. RESULTS: No correlation was found between subjectively measured fatigue and hearing acuity, nor was a group difference found between the normally hearing and the hearing-impaired participants on the fatigue scores. A significant negative correlation was found between self-reported fatigue and PPD. A similar correlation was also found between Speech Intelligibility Index required for 50% correct and PPD. Multiple regression analysis showed that factors representing "hearing acuity" and "self-reported fatigue" had equal and independent associations with the PPD during the speech in noise test. Less fatigue and better hearing acuity were associated with a larger pupil dilation. CONCLUSIONS: To the best of our knowledge, this is the first study to investigate the relationship between a subjective measure of daily-life fatigue and an objective measure of pupil dilation, as an indicator of listening effort. These findings help to provide an empirical link between pupil responses, as observed in the laboratory, and daily-life fatigue.

Effects of Hearing Impairment and Hearing Aid Amplification on Listening Effort: A Systematic Review.

OBJECTIVES: To undertake a systematic review of available evidence on the effect of hearing impairment and hearing aid amplification on listening effort. Two research questions were addressed: Q1) does hearing impairment affect listening effort? and Q2) can hearing aid amplification affect listening effort during speech comprehension? DESIGN: English language articles were identified through systematic searches in PubMed, EMBASE, Cinahl, the Cochrane Library, and PsycINFO from inception to August 2014. References of eligible studies were checked. The Population, Intervention, Control, Outcomes, and Study design strategy was used to create inclusion criteria for relevance. It was not feasible to apply a meta-analysis of the results from comparable studies. For the articles identified as relevant, a quality rating, based on the 2011 Grading of Recommendations Assessment, Development, and Evaluation Working Group guidelines, was carried out to judge the reliability and confidence of the estimated effects. RESULTS: The primary search produced 7017 unique hits using the keywords: hearing aids OR hearing impairment AND listening effort OR perceptual effort OR ease of listening. Of these, 41 articles fulfilled the Population, Intervention, Control, Outcomes, and Study design selection criteria of: experimental work on hearing impairment OR hearing aid technologies AND listening effort OR fatigue during speech perception. The methods applied in those articles were categorized into subjective, behavioral, and physiological assessment of listening effort. For each study, the statistical analysis addressing research question Q1 and/or Q2 was extracted. In seven articles more than one measure of listening effort was provided. Evidence relating to Q1 was provided by 21 articles that reported 41 relevant findings. Evidence relating to Q2 was provided by 27 articles that reported 56 relevant findings. The quality of evidence on both research questions (Q1 and Q2) was very low, according to the Grading of Recommendations Assessment, Development, and Evaluation Working Group guidelines. We tested the statistical evidence across studies with nonparametric tests. The testing revealed only one consistent effect across studies, namely that listening effort was higher for hearing-impaired listeners compared with normal-hearing listeners (Q1) as measured by electroencephalographic measures. For all other studies, the evidence across studies failed to reveal consistent effects on listening effort. CONCLUSION: In summary, we could only identify scientific evidence from physiological measurement methods, suggesting that hearing impairment increases listening effort during speech perception (Q1). There was no scientific, finding across studies indicating that hearing aid amplification decreases listening effort (Q2). In general, there were large differences in the study population, the control groups and conditions, and the outcome measures applied between the studies included in this review. The results of this review indicate that published listening effort studies lack consistency, lack standardization across studies, and have insufficient statistical power. The findings underline the need for a common conceptual framework for listening effort to address the current shortcomings.

A Taxonomy of Fatigue Concepts and Their Relation to Hearing Loss.

Fatigue is common in individuals with a variety of chronic health conditions and can have significant negative effects on quality of life. Although limited in scope, recent work suggests persons with hearing loss may be at increased risk for fatigue, in part due to effortful listening that is exacerbated by their hearing impairment. However, the mechanisms responsible for hearing loss-related fatigue, and the efficacy of audiologic interventions for reducing fatigue, remain unclear. To improve our understanding of hearing loss-related fatigue, as a field it is important to develop a common conceptual understanding of this construct. In this article, the broader fatigue literature is reviewed to identify and describe core constructs, consequences, and methods for assessing fatigue and related constructs. Finally, the current knowledge linking hearing loss and fatigue is described and may be summarized as follows: Hearing impairment may increase the risk of subjective fatigue and vigor deficits; adults with hearing loss require more time to recover from fatigue after work and have more work absences; sustained, effortful, listening can be fatiguing; optimal methods for eliciting and measuring fatigue in persons with hearing loss remain unclear and may vary with listening condition; and amplification may minimize decrements in cognitive processing speed during sustained effortful listening. Future research is needed to develop reliable measurement methods to quantify hearing loss-related fatigue, explore factors responsible for modulating fatigue in people with hearing loss, and identify and evaluate potential interventions for reducing hearing loss-related fatigue.

Hearing Impairment and Cognitive Energy: The Framework for Understanding Effortful Listening (FUEL).

The Fifth Eriksholm Workshop on "Hearing Impairment and Cognitive Energy" was convened to develop a consensus among interdisciplinary experts about what is known on the topic, gaps in knowledge, the use of terminology, priorities for future research, and implications for practice. The general term cognitive energy was chosen to facilitate the broadest possible discussion of the topic. It goes back to who described the effects of attention on perception; he used the term psychic energy for the notion that limited mental resources can be flexibly allocated among perceptual and mental activities. The workshop focused on three main areas: (1) theories, models, concepts, definitions, and frameworks; (2) methods and measures; and (3) knowledge translation. We defined effort as the deliberate allocation of mental resources to overcome obstacles in goal pursuit when carrying out a task, with listening effort applying more specifically when tasks involve listening. We adapted Kahneman's seminal (1973) Capacity Model of Attention to listening and proposed a heuristically useful Framework for Understanding Effortful Listening (FUEL). Our FUEL incorporates the well-known relationship between cognitive demand and the supply of cognitive capacity that is the foundation of cognitive theories of attention. Our FUEL also incorporates a motivation dimension based on complementary theories of motivational intensity, adaptive gain control, and optimal performance, fatigue, and pleasure. Using a three-dimensional illustration, we highlight how listening effort depends not only on hearing difficulties and task demands but also on the listener's motivation to expend mental effort in the challenging situations of everyday life.