Physiological and subjective evaluation of music processing strategies for hearing-impaired listeners: a pilot study
Hearing loss affects over 2.5 billion people worldwide and significantly degrades music enjoyment. While advances in digital signal processing (DSP) aim to improve listening experiences, their combined effects on perceived audio quality and physiological engagement remain underexplored. This pilot study evaluated hearing-impairment-optimised DSP models from the CADENZA challenge. Eleven participants (eight normal-hearing, three hearing-aid users) listened to musical excerpts processed via four DSP algorithms using circumaural open-back headphones in a semi-anechoic chamber. Signal delivery was tailored using personalized audiogram baselines and volume attenuation. Subjective metrics, Basic Audio Quality (BAQ) and likeability, were collected alongside continuous physiological recordings (electrodermal activity [EDA] and photoplethysmography [PPG]) captured with a medical-grade wrist wearable. DSP model E021 consistently achieved the highest BAQ and likeability scores across both participant groups, with BAQ and likeability demonstrating a strong positive correlation. Physiological monitoring revealed exploratory associations between autonomic arousal and variability metrics: specifically, phasic EDA variability and inter-beat interval (IBI) variability positively correlated with both BAQ and likeability. Variability-based physiological markers present viable pathways for evaluating subjective listener responses in small cohorts. Integrating wearable-derived biometric signals with subjective appraisal provides a framework for developing adaptive, listener-aware DSP strategies that enhance music accessibility for individuals with hearing impairment.