Input-related demands: vocoded sentences evoke different pupillometrics and subjective listening effort than sentences in speech-shaped noise.

OBJECTIVES: The Framework for Effortful Listening (FUEL) suggests five input-related demands can alter listening effort: source, transmission, listener, message and context factors. We hypothesised that vocoded sentences represented a source factor degradation and sentences in speech-shaped noise represented a transmission factor degradation. We used pupillometry and a subjective scale to examine our hypothesis. DESIGN: Participants listened to vocoded sentences and sentences in speech-shaped noise at several difficulty levels designed to produce similar word recognition abilities; they also listened to unprocessed sentences. Within-participant pupillometrics and subjective listening effort were analysed. Post-hoc analyses were performed to examine if word recognition accuracy differentially influenced pupil responses. STUDY SAMPLES: Twenty young adults with normal hearing. RESULTS: Baseline pupil diameter was significantly smaller, peak pupil dilation was significantly larger, peak pupil dilation latency was significantly shorter, and subjective listening effort was significantly greater for the vocoded sentences than the sentences-in-noise. Word recognition ability also affected pupillometrics, but only for the vocoded sentences. CONCLUSIONS: Our findings suggest that source factor degradations result in greater listening effort than transmission factor degradations. Future research should address how clinical interventions tailored towards different input-related demands may lead to reduced listening effort and improve patient outcomes.

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.

Factors Associated With Hearing Aid Wear Time in a Subset of U.S. Military Veterans: Tinnitus, the Presence of One or More Neurologic Conditions, and Unaided Speech Intelligibility Index.

PURPOSE: A retrospective analysis was conducted to explore how tinnitus, one or more neurologic conditions, unaided speech intelligibility index, and other comorbidities impact the average number of hours hearing aids are worn each day by U.S. Military Veterans. METHOD: Medical records and a hearing aid database were queried to obtain information regarding active medical problems and average daily hearing aid wear time. Multiple linear regression was used to explore these relationships for 215 male Veterans whose records were available from 2009 to 2020. To be analyzed, Veterans must have possessed their hearing aid(s) for at least 3 consecutive months. RESULTS: An active problem of subjective tinnitus was associated with increased hearing aid wear time (positive association) and one or more active neurologic conditions were associated with decreased hearing aid wear time (negative association). A high unaided speech intelligibility index (greater access to speech sounds without hearing aids) was also associated with decreased hearing aid wear time (negative association). CONCLUSIONS: There are many complex audiologic and medical concerns that may affect hearing aid wear time in U.S. Military Veterans. Therefore, the information from this study should be expanded on prospectively by further exploring these associations, and their severity, on hearing aid wear time. The information from this and future studies may lead to clinical recommendations with the goal of increasing daily hearing aid use in this and other populations.