Spatial auditory change detection in listeners with hearing loss

Everyday listening relies on the auditory systems ability to automatically monitor the background soundscape and detect new or changing sources. Although change detection is a fundamental aspect of situational awareness, little is known about how hearing impairment affects this ability. This study examined how sensorineural hearing loss influences spatial auditory change detection. Older hearing-impaired listeners (N = 30) completed a spatial change detection task requiring them to identify the appearance of a new sound source within a complex spatialised acoustic scene. Hearing loss was characterised by three factors that were measured with standard clinical tests: audiometric hearing thresholds, sensitivity to small level changes, and sensitivity to spectrotemporal modulation. Simple and mixed-effects linear models were used to test how these factors predicted reaction time, hit rate, and false alarm rate. Listeners with poorer spectrotemporal sensitivity, higher audiometric hearing thresholds, and older age showed slower and less accurate detection, whereas sensitivity to small changes in level did not predict outcomes. Detection also varied with spatial location, where appearing sources from behind were detected more slowly and less accurately than those from the front or sides. Numerical analysis using head-related transfer functions confirmed that these rear-field effects were unlikely to be explained by overall or frequency-specific acoustic level differences. These findings reveal that hearing loss, age, and spatial factors jointly shape listeners ability to monitor dynamic auditory scenes. Additionally, testing spectrotemporal sensitivity offers a promising clinical measure of non-speech auditory processing with relevance for hearing-aid fitting and situational awareness.