Type of Resources
Spatial hearing is the ability to use auditory cues to determine the location, direction, and distance of sound in space. Listeners with unilateral hearing loss (UHL) typically have difficulty understanding speech in the presence of competing sound; this is likely due to the lack of access to spatial cues. The assessment of spatial hearing abilities in individuals with UHL is of growing clinical interest, particularly for everyday listening environments. Current approaches used to measure spatial hearing abilities include Spatial Release from Masking (SRM), Binaural Intelligibility Level Difference (BILD), and Listening in Spatialized Noise-Sentences (LiSN-S) test. Spatial Release from Masking is the improvement in speech recognition thresholds (SRT) when the target and masker are co-located as opposed to when they are spatially separated, utilizing a sound-field setup. The LiSN-S test also measures improvement in SRTs when the target and masker are spatially separated. Although similar, the LiSN-S utilizes a more clinically assessable procedure by simulating a three-dimensional auditory environment under headphones. Akin to the LiSN-S, the BILD also utilizes headphones but instead elicits improved SRTs by presenting target speech 180° out-of-phase to one ear instead of in-phase to two ears. The purposes of this study were (a) to determine if patterns of individual variability were similar across the three measures for 30 adults with normal hearing and 28 adults with simulated UHL and (b) to evaluate the effects of simulated UHL on performance. Results of this study confirmed the three tests were all sensitive measures of binaural hearing deficits in participants with UHL. Although all measures were correlated with each other, only the measures conducted under headphones (BILD and LiSN-S) were influenced by magnitude of asymmetry. These findings suggested that although the measures were producing similar results, they might be reflecting different aspects of binaural processing.