Measuring listening effort: driving simulator versus simple dual-task paradigm

Listening handicap in tinnitus patients with normal extended high frequencies from the perspective of the autonomic nervous system-Effort or fatigue?

OBJECTIVE

In previous studies, the results regarding the presence of listening effort or fatigue in tinnitus patients were inconsistent. The reason for this inconsistency could be that extended high frequencies, which can cause listening handicap, were not within normal limits. Therefore, this study aimed to evaluate the listening skills in tinnitus patients by matching the normal hearing thresholds at all frequencies, including the extended high frequency.

METHODS

Eighteen chronic tinnitus patients and thirty matched healthy controls having normal pure-tone average with symmetrical hearing thresholds was included. Subjects were evaluated with 0.125-20 kHz pure-tone audiometry, Montreal cognitive assessment test (MoCA), Tinnitus Handicap Inventory (THI), Matrix Test, Pupillometry.

RESULTS

Pupil dilatation in the 'coding' phase of the sentence presented in tinnitus patients was less than in the control group (p < 0.05). There was no difference between the groups for Matrix test scores (p > 0.05) Also, there was no statistically significant correlation between THI and Pupillometry components nor between MoCA (p > 0.05).

CONCLUSION

Even though tinnitus patients had normal hearing in the range of 0.125-20 kHz, their autonomic nervous system responses during listening differed from healthy subjects. This difference was interpreted for potential listening fatigue in tinnitus patients.

WITHDRAWN: Listening handicap in tinnitus patients by controlling extended high frequencies - Effort or fatigue?

This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error.

Brightening the Study of Listening Effort with Functional Near-Infrared Spectroscopy: A Scoping Review

Listening effort is a long-standing area of interest in auditory cognitive neuroscience. Prior research has used multiple techniques to shed light on the neurophysiological mechanisms underlying listening during challenging conditions. Functional near-infrared spectroscopy (fNIRS) is growing in popularity as a tool for cognitive neuroscience research, and its recent advances offer many potential advantages over other neuroimaging modalities for research related to listening effort. This review introduces the basic science of fNIRS and its uses for auditory cognitive neuroscience. We also discuss its application in recently published studies on listening effort and consider future opportunities for studying effortful listening with fNIRS. After reading this article, the learner will know how fNIRS works and summarize its uses for listening effort research. The learner will also be able to apply this knowledge toward generation of future research in this area.

Dual-Task Paradigm Measures of Listening Effort: To Include or Not to Include Secondary Task Responses with Incorrect Primary Task Responses

Response time–based dual-task paradigms are commonly adopted to measure behavioral listening effort. Most extant studies used an all-response approach that included secondary task responses under both correct and incorrect primary task responses during analysis. However, evidence supporting this strategy is limited. Therefore, the current study investigated the potential differences between including all responses versus only including correct responses. Data from two previous studies were reanalyzed. Experiment 1 included 16 listeners and used a dual-task paradigm to examine the effect of introducing background noise on listening effort. Experiment 2 included 19 participants and used a different dual-task paradigm to examine the effect of reverberation and loudspeaker-to-listener distance on listening effort. ANOVA results obtained using both analysis approaches were compared. The all-response and correct-only approaches revealed similar results. However, larger effect sizes and an additional main effect were found with the all-response approach. The current study supports the use of an all-response approach due to its greater sensitivity to changes in behavioral listening effort. However, a correct-only approach could be utilized to suit specific study purposes.

Exploring the Correlations Between Measures of Listening Effort in Adults and Children: A Systematic Review with Narrative Synthesis

Listening effort (LE) describes the cognitive resources needed to process an auditory message. Our understanding of this notion remains in its infancy, hindering our ability to appreciate how it impacts individuals with hearing impairment effectively. Despite the myriad of proposed measurement tools, a validated method remains elusive. This is complicated by the seeming lack of association between tools demonstrated via correlational analyses. This review aims to systematically review the literature relating to the correlational analyses between different measures of LE. Five databases were used- PubMed, Cochrane, EMBASE, PsychINFO, and CINAHL. The quality of the evidence was assessed using the GRADE criteria and risk of bias with ROBINS-I/GRADE tools. Each statistically significant analysis was classified using an approved system for medical correlations. The final analyses included 48 papers, equating to 274 correlational analyses, of which 99 reached statistical significance (36.1%). Within these results, the most prevalent classifications were poor or fair. Moreover, when moderate or very strong correlations were observed, they tended to be dependent on experimental conditions. The quality of evidence was graded as very low. These results show that measures of LE are poorly correlated and supports the multi-dimensional concept of LE. The lack of association may be explained by considering where each measure operates along the effort perception pathway. Moreover, the fragility of significant correlations to specific conditions further diminishes the hope of finding an all-encompassing tool. Therefore, it may be prudent to focus on capturing the consequences of LE rather than the notion itself.

Interactions between acoustic challenges and processing depth in speech perception as measured by task-evoked pupil response

Speech perception under adverse conditions is a multistage process involving a dynamic interplay among acoustic, cognitive, and linguistic factors. Nevertheless, prior research has primarily focused on factors within this complex system in isolation. The primary goal of the present study was to examine the interaction between processing depth and the acoustic challenge of noise and its effect on processing effort during speech perception in noise. Two tasks were used to represent different depths of processing. The speech recognition task involved repeating back a sentence after auditory presentation (higher-level processing), while the tiredness judgment task entailed a subjective judgment of whether the speaker sounded tired (lower-level processing). The secondary goal of the study was to investigate whether pupil response to alteration of dynamic pitch cues stems from difficult linguistic processing of speech content in noise or a perceptual novelty effect due to the unnatural pitch contours. Task-evoked peak pupil response from two groups of younger adult participants with typical hearing was measured in two experiments. Both tasks (speech recognition and tiredness judgment) were implemented in both experiments, and stimuli were presented with background noise in Experiment 1 and without noise in Experiment 2. Increased peak pupil dilation was associated with deeper processing (i.e., the speech recognition task), particularly in the presence of background noise. Importantly, there is a non-additive interaction between noise and task, as demonstrated by the heightened peak pupil dilation to noise in the speech recognition task as compared to in the tiredness judgment task. Additionally, peak pupil dilation data suggest dynamic pitch alteration induced an increased perceptual novelty effect rather than reflecting effortful linguistic processing of the speech content in noise. These findings extend current theories of speech perception under adverse conditions by demonstrating that the level of processing effort expended by a listener is influenced by the interaction between acoustic challenges and depth of linguistic processing. The study also provides a foundation for future work to investigate the effects of this complex interaction in clinical populations who experience both hearing and cognitive challenges.

Listening Effort in Hearing Aid Users: Is It Related to Hearing Aid Use and Satisfaction?

BACKGROUND

 Listening effort is primarily reflective of real-world performance. Therefore, it is crucial to evaluate the listening effort to predict the performance of hearing aid (HA) users in their daily lives.

PURPOSE

 This study aimed to investigate the relationship between listening effort, daily HA use time, and HA satisfaction.

RESEARCH DESIGN

 This is a cross-sectional study.

STUDY SAMPLE

 Thirty-three bilateral behind-the-ear HA users (17 females and 16 males) between 19 and 37 years were participated. All participants had bilateral, symmetric, moderate sensorineural hearing loss and at least 6 months of experience using HAs. The pure-tone average thresholds (PTA) of the participants' left and right ears were 55.34 ± 4.38 and 54.85 ± 5.05, respectively.

DATA COLLECTION AND ANALYSIS

 First, daily HA use times of the last 30 days were derived from data logging. Second, participants were asked to fill in the Satisfaction with Amplification in Daily Life Scale questionnaire (SADL). Lastly, participants performed the dual-task paradigm to evaluate listening effort. The dual-task paradigm consisted of a primary speech recognition task that included three different individualized signal-to-noise ratio (SNR) conditions, that is, SNR100, SNR80, and SNR50, which the participant could understand 100, 80, and 50% of the speech, respectively. The secondary task was a visual reaction time task that required participants to press the key in response to a visual probe (an image of a white or red rectangle). Multiple linear regression analyses were used to model the effect of factors (daily HA use time and HA satisfaction) on reaction times (RT) of each three individualized SNR sessions.

RESULTS

 Mean daily HA use time of the participants was 5.72 ± 4.14 hours. Mean RTs of SNR50, SNR80, and SNR100 conditions were 1,050.61 ± 286.49, 893.33 ± 274.79, and 815.45 ± 233.22 ms, respectively. Multiple linear regression analyses showed that daily HA use time and HA satisfaction are significantly related to listening effort in all SNR conditions. For SNR80 condition; F (2,30) = 47.699, p < 0.001, with an adjusted R 2 of 0.745.

CONCLUSION

 As far as we know, this study is the first to demonstrate a strong link between listening effort, daily HA use time, and HA satisfaction. Evaluating listening effort following the HA fitting session may provide preliminary information about the treatment success of HA.

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.

Listen before you drive: the effect of voice familiarity on listening comprehension and driving performance

OBJECTIVE

Voice familiarity has been reported to reduce cognitive load in complex listening environments. The extent to which the reduction in listening effort allows for mental resources to be reallocated to other complex tasks needs further investigation. We sought to answer whether a familiar audiobook narrator provides benefits to (1) listening comprehension and/or (2) driving performance.

DESIGN

A double-blind between-groups design was implemented. Participants were randomly assigned to the Familiar group or the Unfamiliar group.

STUDY SAMPLE

Participants (n = 30) were normal-hearing adults, 18 to 28-years-old (M = 23, SD = 2.6) (n = 18 female). Participants first listened to an audiobook read by either Voice 1 (Familiar condition) or Voice 2 (Unfamiliar condition). Then they completed a virtual reality driving task while listening to a second audiobook, always read by Voice 1. Audiobook comprehension (30-question multiple-choice test) and driving performance (number of driving errors made) were recorded.

RESULTS

Participants in the Familiar group made fewer driving errors than participants in the Unfamiliar group. There were no differences in listening comprehension.

CONCLUSIONS

Increased voice familiarity positively impacts behaviour (i.e. reduced driving errors) in normal-hearing adults. We discuss our findings in the context of effortful listening frameworks.

The Cost of Intrinsic and Extrinsic Cognitive Demands on Auditory Functioning in Older Adults With Normal Hearing or Using Hearing Aids

OBJECTIVES

We investigated the impact of both intrinsic and extrinsic cognitive demands on auditory and secondary task performance in older adults with normal hearing (NH) and adults using hearing aids (HAs) in an ecologically relevant listening environment.

DESIGN

Fifteen adults with NH and 15 adults using HAs (60 to 72 years of age) were recruited to perform the "Audiovisual True-to-Life Assessment of Auditory Rehabilitation"-paradigm (AVATAR), which combines an auditory-visual speech-in-noise task with three secondary tasks on either auditory localization or visual short-term memory in a preload multitask paradigm. Intrinsic demands were altered by presenting speech either at equivalent speech accuracy levels of 50% correct (SPIN50%) or equivalent speech-to-noise ratios of +5dB SNR (SPIN+5dB). We manipulated the amount of extrinsic cognitive demands by including one (dual condition) or three secondary tasks (quadruple condition). Performance decrements on the secondary tasks were considered to reflect an increase in resource allocation to speech understanding and thus an increase in listening effort. In addition, we administered a cognitive test battery as well as a questionnaire on self-reported hearing difficulties and subjective measures of effort and motivation.

RESULTS

Speech understanding and secondary task performance on the visual short-term memory task were lower in the SPIN50% condition compared to SPIN+5dB. Whereas speech understanding at SPIN50% was equally high in the dual and quadruple conditions, the quadruple condition resulted in lower secondary task performance on the visual short-term memory task, higher levels of self-reported effort, and lower motivation compared to the dual-task condition. The same was true for experimental conditions at SPIN+5dB. Additionally, adults with NH outperformed adults using HAs on speech understanding, auditory localization, and self-reported hearing abilities, but no group differences were observed on secondary task costs or cognitive measures.

CONCLUSIONS

This study showed that, irrespective of the hearing status of the listener, speech performance was not affected by the amount of extrinsic cognitive demands, but was worse and required more effort under conditions with a more negative SNR. Also, increasing the extrinsic cognitive demands resulted in lower performance on one of the secondary tasks, suggesting that more complex listening environments require more effort. Although adults with NH outperformed HA users on speech understanding and auditory localization, the two groups did not differ with respect to secondary task costs.

Comparisons of the Sensitivity and Reliability of Multiple Measures of Listening Effort

OBJECTIVES

The objective of this study was to evaluate the sensitivity and reliability of one subjective (rating scale) and three objective (dual-task paradigm, pupillometry, and skin conductance response amplitude) measures of listening effort across multiple signal to noise ratios (SNRs).

DESIGN

Twenty adults with normal hearing attended two sessions and listened to sentences presented in quiet and in stationary noise at three different SNRs: 0, -3, and -5 dB. Listening effort was assessed by examining change in reaction time (dual-task paradigm), change in peak to peak pupil diameter (pupillometry), and change in mean skin conductance response amplitude; self-reported listening effort on a scale from 0 to 100 was also evaluated. Responses were averaged within each SNR and based on three word recognition ability categories (≤50%, 51% to 71%, and >71%) across all SNRs. Measures were considered reliable if there were no significant changes between sessions, and intraclass correlation coefficients were a minimum of 0.40. Effect sizes were calculated to compare the sensitivity of the measures.

RESULTS

Intraclass correlation coefficient values indicated fair-to-moderate reliability for all measures while individual measurement sensitivity was variable. Self-reports were sensitive to listening effort but were less reliable, given that subjective effort was greater during the dual task than either of the physiologic measures. The dual task was sensitive to a narrow range of word recognition abilities but was less reliable as it exhibited a global decrease in reaction time across sessions. Pupillometry was consistently sensitive and reliable to changes in listening effort. Skin conductance response amplitude was not sensitive or reliable while the participants listened to the sentences. Skin conductance response amplitude during the verbal response was sensitive to poor (≤50%) speech recognition abilities; however, it was less reliable as there was a significant change in amplitude across sessions.

CONCLUSIONS

In this study, pupillometry was the most sensitive and reliable objective measure of listening effort. Intersession variability significantly influenced the other objective measures of listening effort, which suggests challenges for cross-study comparability. Therefore, intraclass correlation coefficients combined with other statistical tests more fully describe the reliability of measures of listening effort across multiple difficulties. Minimizing intersession variability will increase measurement sensitivity. Further work toward standardized methods and analysis will strengthen our understanding of the reliability and sensitivity of measures of listening effort and better facilitate cross-modal and cross-study comparisons.

The Speaker's Experience of Stuttering: Measuring Spontaneity

Purpose This study measures the experience of spontaneous speech in everyday speaking situations. Spontaneity of speech is a novel concept developed to account for the subjective experience of speaking. Spontaneous speech is characterized by little premeditation and effortless production, and it is enjoyable and meaningful. Attention is not directed on the physical production of speech. Spontaneity is intended to be distinct from fluency so that it can be used to describe both stuttered and fluent speech. This is the first study to attempt to measure the concept of spontaneity of speech. Method The experience sampling method was used with 44 people who stutter. They were surveyed five times a day for 1 week through their cell phones. They reported on their perceived spontaneity, fluency, and speaking context. Results Results indicate that spontaneity and fluency are independent, though correlated, constructs that vary with context. Importantly, an increase in spontaneity significantly decreases the adverse impact of stuttering on people's lives. Fluency did not significantly affect adverse life impact of stuttering. Conclusion Findings support a theoretical construct of spontaneity that is distinct from speech fluency and that can inform our views of stuttering and approaches to stuttering treatment.

Long-term evolution of the electrical stimulation for cochlear implant adult patients. The role of a progressive adaptation method

Background: In clinical experience patients who do not frequently check the cochlear implant (CI) maps have poor auditory performance and poor acceptance of map variations over time.Aims: The aim of the present study was to evaluate the effect of CI map optimization on both speech perception and subjective hearing in a group of CI patients with a long-standing map.Material and methods: 14 patients (6 females and 8 males; age range 16-77, mean age 45.86 ± 23.85 years) fitted with a unilateral CI (Cochlear Ltd, Sydney, Australia) and a map unchanged for at least 12 months were evaluated. All CIs were remapped using mapping method with progressive adaptation. The speech discrimination in noise and subjective hearing perception (SSQ questionnaire) were evaluated with old and new map.Results: The differences in electrode level with old and new map were significantly different both for T and C- Levels (p < .001). Speech discrimination in noise was significantly better (22.9%; p < .0001) after map optimization. The SSQ questionnaire showed no statistically significant difference in the overall scores, except the listening effort sub-scale.Conclusions: Longstanding MAPs are associated with poor speech discrimination. Degradation of electrical stimulation is associated with increased mental effort.

Validação de conteúdo de um instrumento para mensuração do esforço auditivo

RESUMO Objetivo: Validar o conteúdo de um instrumento para mensuração do esforço auditivo para indivíduos com perda auditiva. Método: Trata-se de um estudo de validação, desenvolvido em duas fases, sendo a fase 1 o planejamento e desenvolvimento da primeira versão do instrumento e a fase 2 a investigação das evidências de validade baseadas no conteúdo do instrumento e desenvolvimento da versão final para mensuração de esforço auditivo. Participaram dez profissionais com expertise na área audiológica, com mais de cinco anos de experiência. O instrumento a ser validado foi composto por três partes: I - “percepção de fala de logatomas e esforço auditivo”; II - “esforço auditivo e memória operacional”; e III - “percepção de sentenças sem sentido e memória operacional”, apresentadas de forma monoaural no silêncio e nas relações sinal-ruído +5dB, 0dB e -5dB. Foi realizada a análise descritiva das sugestões do comitê de fonoaudiólogos e do índice de validade de conteúdo individual e total. Resultados: Os resultados mostraram que as partes I e III do instrumento proposto atingiram o índice de validade de conteúdo total acima de 0,78, ou seja, os itens apresentados não necessitaram de modificações em seu constructo. Conclusão: As evidências de validade estudadas permitiram relevantes modificações e tornaram esse instrumento adequado ao seu constructo.

Listening Effort Among Adults With and Without Attention-Deficit/Hyperactivity Disorder

Purpose Few studies have assessed listening effort (LE)-the cognitive resources required to perceive speech-among populations with intact hearing but reduced availability of cognitive resources. Attention/deficit/hyperactivity disorder (ADHD) is theorized to restrict attention span, possibly making speech perception in adverse conditions more challenging. This study examined the effect of ADHD on LE among adults using a behavioral dual-task paradigm (DTP). Method Thirty-nine normal-hearing adults (aged 21-27 years) participated: 19 with ADHD (ADHD group) and 20 without ADHD (control group). Baseline group differences were measured in visual and auditory attention as well as speech perception. LE using DTP was assessed as the performance difference on a visual-motor task versus a simultaneous auditory and visual-motor task. Results Group differences in attention were confirmed by differences in visual attention (larger reaction times between congruent and incongruent conditions) and auditory attention (lower accuracy in the presence of distractors) among the ADHD group, compared to the controls. LE was greater among the ADHD group than the control group. Nevertheless, no group differences were found in speech perception. Conclusions LE is increased among those with ADHD. As a DTP assumes limited cognitive capacity to allocate attentional resources, LE among those with ADHD may be increased because higher level cognitive processes are more taxed in this population. Studies on LE using a DTP should take into consideration mechanisms of selective and divided attention. Among young adults who need to continuously process great volumes of auditory and visual information, much more effort may be expended by those with ADHD than those without it. As a result, those with ADHD may be more prone to fatigue and irritability, similar to those who are engaged in more outwardly demanding tasks.

Listening effort and working memory capacity in hearing impaired individuals: an integrative literature review

ABSTRACT Purpose: to review the literature on the behavioral methods of listening effort assessment and the working memory capacity recommended for the hearing impaired. Methods: this review was developed through the search of articles in national and international journals, in English and Portuguese, available in Pubmed/Medline, Cochrane Library, Biblioteca Vitual em Saúde - Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) and Scientific Electronic Library Online, between 2007 and 2017. The articles were selected based on the inclusion criteria: articles that used behavioral methods to assess listening effort in hearing-impaired adults, involving the measurement of working memory and its relationship with the listening effort, published in the last 10 years. Results: Twelve articles in which behavioral measures were used to measure listening effort and working memory capacity in the hearing-impaired individuals were reviewed. Their main findings refer to the purpose(s) of the research, participants, behavioral method composed of a primary task (speech perception) and a secondary task (memorization) and results of the studies. Conclusion:the findings of this review allow us to infer that this paradigm is sensitive to measure the listening effort, considering the different instruments used and the population assessed.

Measuring Listening Effort: Convergent Validity, Sensitivity, and Links With Cognitive and Personality Measures

PURPOSE

Listening effort (LE) describes the attentional or cognitive requirements for successful listening. Despite substantial theoretical and clinical interest in LE, inconsistent operationalization makes it difficult to make generalizations across studies. The aims of this large-scale validation study were to evaluate the convergent validity and sensitivity of commonly used measures of LE and assess how scores on those tasks relate to cognitive and personality variables.

METHOD

Young adults with normal hearing (N = 111) completed 7 tasks designed to measure LE, 5 tests of cognitive ability, and 2 personality measures.

RESULTS

Scores on some behavioral LE tasks were moderately intercorrelated but were generally not correlated with subjective and physiological measures of LE, suggesting that these tasks may not be tapping into the same underlying construct. LE measures differed in their sensitivity to changes in signal-to-noise ratio and the extent to which they correlated with cognitive and personality variables.

CONCLUSIONS

Given that LE measures do not show consistent, strong intercorrelations and differ in their relationships with cognitive and personality predictors, these findings suggest caution in generalizing across studies that use different measures of LE. The results also indicate that people with greater cognitive ability appear to use their resources more efficiently, thereby diminishing the detrimental effects associated with increased background noise during language processing.

Impact of SNR, masker type and noise reduction processing on sentence recognition performance and listening effort as indicated by the pupil dilation response

Recent studies have shown that activating the noise reduction scheme in hearing aids results in a smaller peak pupil dilation (PPD), indicating reduced listening effort, at 50% and 95% correct sentence recognition with a 4-talker masker. The objective of this study was to measure the effect of the noise reduction scheme (on or off) on PPD and sentence recognition across a wide range of signal-to-noise ratios (SNRs) from +16 dB to -12 dB and two masker types (4-talker and stationary noise). Relatively low PPDs were observed at very low (-12 dB) and very high (+16 dB to +8 dB) SNRs presumably due to 'giving up' and 'easy listening', respectively. The maximum PPD was observed with SNRs at approximately 50% correct sentence recognition. Sentence recognition with both masker types was significantly improved by the noise reduction scheme, which corresponds to the shift in performance from SNR function at approximately 5 dB toward a lower SNR. This intelligibility effect was accompanied by a corresponding effect on the PPD, shifting the peak by approximately 4 dB toward a lower SNR. In addition, with the 4-talker masker, when the noise reduction scheme was active, the PPD was smaller overall than that when the scheme was inactive. We conclude that with the 4-talker masker, noise reduction scheme processing provides a listening effort benefit in addition to any effect associated with improved intelligibility. Thus, the effect of the noise reduction scheme on listening effort incorporates more than can be explained by intelligibility alone, emphasizing the potential importance of measuring listening effort in addition to traditional speech reception measures.

Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm

Published investigations (n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants’ age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified.

Using the device-oriented subjective outcome (DOSO) scale to measure outcomes of different hearing aids

OBJECTIVE

The device-oriented subjective outcome (DOSO) is a device-oriented questionnaire, intended to minimise the influence of personality on self-reported measures. The aim of this study was to provide normative data with 2015-era hearing aid technologies.

DESIGN

This retrospective study evaluated data from records of three clinical trials. The DOSO was administered for the participants' own devices as a part of the intake and after using research devices in the field.

STUDY SAMPLE

The DOSO data were collected from 132 experienced bilateral hearing aid wearers who participated in the clinical trials.

RESULTS

The DOSO data collected with the participants' own devices were compared to the interim normative data collected between 2004 and 2005. The DOSO subscale scores from the participants' own devices were significantly higher than those from the interim norms, except Listening Effort subscale. To demonstrate the utility of the new norms, a separate set of DOSO data collected from the same participants after using research hearing aids were contrasted to the new normative data. After accounting for possible placebo effects, the DOSO data with research devices revealed additional self-reported benefit of technological advancements.

CONCLUSIONS

Norms for the DOSO are recommended for evaluating hearing aids with more recent technologies.

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.

Semantic context improves speech intelligibility and reduces listening effort for listeners with hearing impairment

OBJECTIVE

We investigated whether speech intelligibility and listening effort for hearing-aid users is affected by semantic context and hearing-aid setting.

DESIGN

Participants heard target sentences spoken in a reverberant background of cafeteria noise and competing speech. Participants reported each sentence verbally. Eight participants also rated listening effort after each sentence. Sentence topic was either the same as, or different from, the previous target sentence.

STUDY SAMPLE

Twenty participants with sensorineural hearing loss were fit binaurally with Signia receiver-in-the-canal hearing aids. Participants performed the task twice: once using the hearing aid's omnidirectional setting and once using the "Reverberant Room" setting, designed to aid listening in reverberant environments.

RESULTS

Participants achieved better speech intelligibility for same-topic than different-topic sentences, and when they used the "Reverberant Room" than the omnidirectional hearing-aid setting. Participants who rated effort showed a reliable reduction in listening effort for same-topic sentences and for the "Reverberant Room" hearing-aid setting. The improvement in speech intelligibility from semantic context (i.e. same-topic compared to different-topic sentences) was greater than the improvement gained from changing hearing-aid setting.

CONCLUSIONS

These findings highlight the enormous potential of cognitive (specifically, semantic) factors for improving speech intelligibility and reducing perceived listening effort in noise for hearing-aid users.

Psychometric Functions of Dual-Task Paradigms for Measuring Listening Effort

OBJECTIVES

The purpose of the study was to characterize the psychometric functions that describe task performance in dual-task listening effort measures as a function of signal to noise ratio (SNR).

DESIGN

Younger adults with normal hearing (YNH, n = 24; experiment 1) and older adults with hearing impairment (n = 24; experiment 2) were recruited. Dual-task paradigms wherein the participants performed a primary speech recognition task simultaneously with a secondary task were conducted at a wide range of SNRs. Two different secondary tasks were used: an easy task (i.e., a simple visual reaction-time task) and a hard task (i.e., the incongruent Stroop test). The reaction time (RT) quantified the performance of the secondary task.

RESULTS

For both participant groups and for both easy and hard secondary tasks, the curves that described the RT as a function of SNR were peak shaped. The RT increased as SNR changed from favorable to intermediate SNRs, and then decreased as SNRs moved from intermediate to unfavorable SNRs. The RT reached its peak (longest time) at the SNRs at which the participants could understand 30 to 50% of the speech. In experiments 1 and 2, the dual-task trials that had the same SNR were conducted in one block. To determine if the peak shape of the RT curves was specific to the blocked SNR presentation order used in these experiments, YNH participants were recruited (n = 25; experiment 3) and dual-task measures, wherein the SNR was varied from trial to trial (i.e., nonblocked), were conducted. The results indicated that, similar to the first two experiments, the RT curves had a peak shape.

CONCLUSIONS

Secondary task performance was poorer at the intermediate SNRs than at the favorable and unfavorable SNRs. This pattern was observed for both YNH and older adults with hearing impairment participants and was not affected by either task type (easy or hard secondary task) or SNR presentation order (blocked or nonblocked). The shorter RT at the unfavorable SNRs (speech intelligibility < 30%) possibly reflects that the participants experienced cognitive overload and/or disengaged themselves from the listening task. The implication of using the dual-task paradigm as a listening effort measure is discussed.

Listening in Naturalistic Scenes: What Can Functional Near-Infrared Spectroscopy and Intersubject Correlation Analysis Tell Us About the Underlying Brain Activity?

Listening to speech in the noisy conditions of everyday life can be effortful, reflecting the increased cognitive workload involved in extracting meaning from a degraded acoustic signal. Studying the underlying neural processes has the potential to provide mechanistic insight into why listening is effortful under certain conditions. In a move toward studying listening effort under ecologically relevant conditions, we used the silent and flexible neuroimaging technique functional near-infrared spectroscopy (fNIRS) to examine brain activity during attentive listening to speech in naturalistic scenes. Thirty normally hearing participants listened to a series of narratives continuously varying in acoustic difficulty while undergoing fNIRS imaging. Participants then listened to another set of closely matched narratives and rated perceived effort and intelligibility for each scene. As expected, self-reported effort generally increased with worsening signal-to-noise ratio. After controlling for better-ear signal-to-noise ratio, perceived effort was greater in scenes that contained competing speech than in those that did not, potentially reflecting an additional cognitive cost of overcoming informational masking. We analyzed the fNIRS data using intersubject correlation, a data-driven approach suitable for analyzing data collected under naturalistic conditions. Significant intersubject correlation was seen in the bilateral auditory cortices and in a range of channels across the prefrontal cortex. The involvement of prefrontal regions is consistent with the notion that higher order cognitive processes are engaged during attentive listening to speech in complex real-world conditions. However, further research is needed to elucidate the relationship between perceived listening effort and activity in these extended cortical networks.

Waiting for lexical access: Cochlear implants or severely degraded input lead listeners to process speech less incrementally

Spoken language unfolds over time. Consequently, there are brief periods of ambiguity, when incomplete input can match many possible words. Typical listeners solve this problem by immediately activating multiple candidates which compete for recognition. In two experiments using the visual world paradigm, we examined real-time lexical competition in prelingually deaf cochlear implant (CI) users, and normal hearing (NH) adults listening to severely degraded speech. In Experiment 1, adolescent CI users and NH controls matched spoken words to arrays of pictures including pictures of the target word and phonological competitors. Eye-movements to each referent were monitored asa measure of how strongly that candidate was considered over time. Relative to NH controls, CI users showed a large delay in fixating any object, less competition from onset competitors (e.g., sandwich after hearing sandal), and increased competition from rhyme competitors (e.g., candle after hearing sandal). Experiment 2 observed the same pattern with NH listeners hearing highly degraded speech. These studies suggests that in contrast to all prior studies of word recognition in typical listeners, listeners recognizing words in severely degraded conditions can exhibit a substantively different pattern of dynamics, waiting to begin lexical access until substantial information has accumulated.

Child-Adult Differences in Using Dual-Task Paradigms to Measure Listening Effort

PURPOSE

The purpose of the project was to investigate the effects modifying the secondary task in a dual-task paradigm to measure objective listening effort. To be specific, the complexity and depth of processing were increased relative to a simple secondary task.

METHOD

Three dual-task paradigms were developed for school-age children. The primary task was word recognition. The secondary task was a physical response to a visual probe (simple task), a physical response to a complex probe (increased complexity), or word categorization (increased depth of processing). Sixteen adults (22-32 years, M = 25.4) and 22 children (9-17 years, M = 13.2) were tested using the 3 paradigms in quiet and noise.

RESULTS

For both groups, manipulations of the secondary task did not affect word recognition performance. For adults, increasing depth of processing increased the calculated effect of noise; however, for children, results with the deep secondary task were the least stable.

CONCLUSIONS

Manipulations of the secondary task differentially affected adults and children. Consistent with previous findings, increased depth of processing enhanced paradigm sensitivity for adults. However, younger participants were more likely to demonstrate the expected effects of noise on listening effort using a secondary task that did not require deep processing.

The Effects of Directional Processing on Objective and Subjective Listening Effort

PURPOSE

The purposes of this investigation were (a) to evaluate the effects of hearing aid directional processing on subjective and objective listening effort and (b) to investigate the potential relationships between subjective and objective measures of effort.

METHOD

Sixteen adults with mild to severe hearing loss were tested with study hearing aids programmed with 3 settings: omnidirectional, fixed directional, and bilateral beamformer. A dual-task paradigm and subjective ratings were used to assess objective and subjective listening effort, respectively, in 2 signal-to-noise ratios. Testing occurred in rooms with either low or moderate reverberation.

RESULTS

Directional processing improved subjective and objective listening effort, although benefit for objective effort was found only in moderate reverberation. Subjective reports of work and tiredness were more highly correlated with word recognition performance than objective listening effort. However, subjective ratings about control were significantly correlated with objective listening effort.

CONCLUSIONS

Directional microphone technology in hearing aids has the potential to improve listening effort in moderately reverberant environments. In addition, subjective questions that probe a listener's desire to exercise control may be a viable method for eliciting ratings that are significantly related to objective listening effort.

Monaural Beamforming in Bimodal Cochlear Implant Users: Effect of (A)symmetric Directivity and Noise Type

OBJECTIVE

To evaluate monaural beamforming in bimodally aided cochlear implant (CI) users.

DESIGN

The study enrolled twelve adult bimodal listeners with at least six months of CI-experience and using a contralateral hearing aid (HA) most of the daytime. Participants were uniformly fitted with the same CI speech processor and HA, giving access to an identical monaural beamformer in both ears. A within-subject repeated measures design evaluated three directional configurations [omnidirectional, asymmetric directivity (in CI alone) and symmetric directivity (in both CI and HA)] in two noise types [stationary and fluctuating]. Bimodal speech reception thresholds (SRT) as well as listening effort ratings were assessed in a diffuse noise field.

RESULTS

Symmetric monaural beamforming provided a significant SRT improvement of 2.6 dB SNR, compared to 1.6 dB SNR for asymmetric monaural beamforming. Directional benefits were similarly observed in stationary and fluctuating noise. Directivity did not contribute to less listening effort in addition to improvement in speech intelligibility. Bimodal performance was about 7 dB SNR worse in fluctuating than in stationary noise.

CONCLUSIONS

Monaural beamforming provided substantial benefit for speech intelligibility in noise for bimodal listeners. The greatest benefit occurred when monaural beamforming was activated symmetrically in both CI and HA. Monaural beamforming does not bridge the gap between bimodal and normal hearing performance, especially in fluctuating noise. Results advocate further bimodal co-operation.

TRIAL REGISTRATION

This trial was registered in www.trialregister.nl under number NTR4901.

The Just-Meaningful Difference in Speech-to-Noise Ratio

The speech-to-noise ratio (SNR) in an environment plays a vital role in speech communication for both normal-hearing (NH) and hearing-impaired (HI) listeners. While hearing-assistance devices attempt to deliver as favorable an SNR as possible, there may be discrepancies between noticeable and meaningful improvements in SNR. Furthermore, it is not clear how much of an SNR improvement is necessary to induce intervention-seeking behavior. Here, we report on a series of experiments examining the just-meaningful difference (JMD) in SNR. All experiments used sentences in same-spectrum noise, with two intervals on each trial mimicking examples of pre- and post-benefit situations. Different groups of NH and HI adults were asked (a) to rate how much better or worse the change in SNR was in a number of paired examples, (b) if they would swap the worse for the better SNR (e.g., their current device for another), or (c) if they would be willing to go to the clinic for the given increase in SNR. The mean SNR JMD based on better or worse ratings (one arbitrary unit) was similar to the just-noticeable difference, approximately 3 dB. However, the mean SNR JMD for the more clinically relevant tasks-willingness (at least 50% of the time) to swap devices or attend the clinic for a change in SNR--was 6 to 8 dB regardless of hearing ability. This SNR JMD of the order of 6 dB provides a new benchmark, indicating the SNR improvement necessary to immediately motivate participants to seek intervention.

Commentary: listening can be exhausting--fatigue in children and adults with hearing loss

Anecdotal reports of fatigue after sustained speech-processing demands are common among adults with hearing loss; however, systematic research examining hearing loss-related fatigue is limited, particularly with regard to fatigue among children with hearing loss (CHL). Many audiologists, educators, and parents have long suspected that CHL experience stress and fatigue as a result of the difficult listening demands they encounter throughout the day at school. Recent research in this area provides support for these intuitive suggestions. In this article, the authors provide a framework for understanding the construct of fatigue and its relation to hearing loss, particularly in children. Although empirical evidence is limited, preliminary data from recent studies suggest that some CHL experience significant fatigue-and such fatigue has the potential to compromise a child's performance in the classroom. In this commentary, the authors discuss several aspects of fatigue including its importance, definitions, prevalence, consequences, and potential linkage to increased listening effort in persons with hearing loss. The authors also provide a brief synopsis of subjective and objective methods to quantify listening effort and fatigue. Finally, the authors suggest a common-sense approach for identification of fatigue in CHL; and, the authors briefly comment on the use of amplification as a management strategy for reducing hearing-related fatigue.