Over-the-Counter Hearing Aids and Listening Effort: A Pupillometry Study

Abstract

Background: Over-the-counter (OTC) hearing aids are designed to improve speech understanding for adults with mild-to-moderate hearing loss. However, challenging listening environments often require substantial effort to process speech, potentially limiting communication and contributing to stress or fatigue. Despite this, limited research has examined whether OTC hearing aids reduce listening effort, particularly in speech-in-noise situations. Purpose: We explored the effects of preset OTC hearing aids on subjective and objective measures of listening effort during speech recognition in noise. Research Design: The study had a within-subjects design. Study Sample: Participants were 16 adults with mild-to-moderate sensorineural hearing loss. Data Collection and Analysis: Participants completed a sentences-in-noise task at 5- and 10-dB signal-to-noise ratios (SNRs) in three hearing aid conditions: unaided (OFF), a participant-assigned OTC program (Mild or Moderate gain), and a directionality-based noise-management program (Noise program). Listening effort was measured using subjective ratings and pupillometry. Generalized additive mixed models evaluated time-course differences in pupil dilation during speech processing and sentence retention. Results: Speech recognition did not significantly differ across hearing aid conditions for any SNR/context condition. Subjective listening effort ratings revealed significant overall effects of hearing aid conditions and SNR/context, with greater listening effort reported for more challenging conditions. Pairwise comparisons indicated significantly greater subjective effort with the Noise program relative to the unaided condition for low-context sentences presented at 10 dB SNR. Pupil dilation differed across hearing aid conditions in both the speech processing and retention windows, although effects varied by SNR and sentence context. During the speech processing window, hearing aid–related differences were modest and variable. In contrast, more robust and sustained differences were observed during retention, with the Mild/Moderate programs generally eliciting larger pupil dilations relative to the unaided listening. The Noise program produced more variable pupil responses and often reduced dilation relative to the Mild/Moderate programs. Conclusions: Preset OTC hearing aids did not consistently reduce subjective or physiological indices of listening effort at first fit. Pupillometry demonstrated amplification-related differences in pupil dilation, particularly during retention, with the Mild/Moderate programs generally associated with larger pupil responses relative to unaided listening. Speech recognition performance did not significantly differ across hearing aid conditions. These findings suggest that preset OTC hearing aids may not consistently reduce cognitive processing demands during speech-in-noise listening immediately after first fitting. Clinical Relevance Statement: Adults with mild-to-moderate hearing loss may expect OTC hearing aids to reduce listening effort in noise. However, the preset OTC hearing aids in this study did not consistently reduce listening effort at first fitting and amplification-related differences in pupil dilation were observed under some conditions. These findings highlight the importance of counseling patients about realistic expectations for preset OTC devices, particularly during initial use, and suggest that individualized fitting, acclimatization, and device selection may influence listening outcomes with OTC hearing aids.