Effect of gap detection threshold and localisation acuity on spatial release from masking in older adults.

OBJECTIVE The primary objective of this experiment was to measure the temporal and spatial processing capabilities of older individuals and use statistical models to identify the individual contributions of these temporal and spatial processing capabilities to spatial release from masking (SRM). DESIGN Repeated measures. STUDY SAMPLE Twenty-five older listeners with varying degrees of hearing loss participated in this experiment. SRM using the coordinate response measure, gap detection thresholds and localisation acuity for 1/3-octave-wide Gaussian noise bands centred at 500 and 4000 Hz were measured for all the listeners. RESULTS Older listeners had better speech recognition thresholds when target and maskers were spatially separated as compared to when they were co-located. In addition, hearing loss and localisation acuity at 500 Hz were significant predictors in a multiple regression model predicting SRM. However, gap detection thresholds did not significantly contribute to the multiple regression model predicting SRM. CONCLUSION Based on our data, we conclude that SRM at 30° spatial separation between the target and symmetric maskers is driven by the ability of the individuals to use interaural time difference cues.