The acoustic change complex evoked by location-change sounds in the elderly.

Abstract

Objective: We have shown that the acoustic change complex (ACC) can be elicited by changing the horizontal sound location in young individuals. In this study, we aimed to evaluate the application of ACC within the elderly and its relationship with behavioural results.

Design: The minimum audible angle (MAA), as well as onset cortical auditory evoked potentials (onset-CAEPs) and ACC elicited by the stimuli of location-change white noise (±45 to ±2 degrees) were recorded. Latencies and amplitudes were analysed using repeated-measures ANOVA. Pearson correlation analysis was conducted to examine the relationship between ACC and MAA.

Study sample: Ten older adults with normal hearing (NH) and twenty with presbycusis.

Results: The ACC was effectively elicited with angular variations in elderly participants. The onset-CAEP N1 latency, ACC N1'-P2' amplitude, and N1' latency were all associated with the angle shifts, with the N1' latency being the most predictive factor for angle discrimination. The consistency between MAA and ACC made them complementary for the clinical evaluation of sound localisation.

Conclusions: The utilisation of ACC, evoked by location-change sounds, presented a promising clinical objective measure for evaluating sound localisation abilities in the elderly.