Release from masking for small spatial separations: Effects of age and hearing loss

Abstract

Spatially separating target and masking speech can result in substantial spatial release from masking (SRM) for normal-hearing listeners. In this study, SRM was examined at eight spatial configurations of azimuth angle: maskers co-located with the target (0°) or symmetrically separated by 2°, 4°, 6°, 8°, 10°, 15°, or 30°. Results revealed that different listening groups (young normal-hearing, older normal-hearing, and older hearing-impaired) required different minimum amounts of spatial separation between target and maskers to achieve SRM. The results also indicated that aging was the contributing factor predicting SRM at smaller separations, whereas hearing loss was the contributing factor at larger separations.

Cortical and Sensory Causes of Individual Differences in Selective Attention Ability Among Listeners With Normal Hearing Thresholds

“…Still, it is clear that the acoustic features that support object formation rely on fine spectral and temporal features of sound, such as harmonic structure, interaural differences, timbre, and other features (Bregman, 1990;Carlyon, 2004;Darwin, 1997). It thus makes sense that listeners with elevated hearing thresholds, who have broader-than-normal cochlear tuning, poor temporal resolution, and reduced dynamic range, will have difficulty communicating in cocktail party settings (e.g., see Best, Mason, & Kidd, 2011;Best, Mason, Kidd, Iyer, & Brungart, 2015;Gallun, Diedesch, Kampel, & Jakien, 2013;Jakien, Kampel, Gordon, & Gallun, 2017;Roverud, Best, Mason, Swaminathan, & Kidd, 2016;Srinivasan, Jakien, & Gallun, 2016; see also the discussion in . However, even listeners with NHTs may differ in the fidelity with which their ears encode acoustic inputs, which may in turn affect their ability to extract auditory objects from a complex acoustic mixture.…”

The role of early and late reflections on spatial release from masking: Effects of age and hearing loss

“…One limitation of this approach, however, is a fairly high correlation [r(42) ¼ 0.55, p < 0.001] between age and PTA. To address this, multiple regression approaches employed by Srinivasan et al (2016) were used to remove the potential confounding correlation between age and PTA to evaluate the individual contributions of each of the confounding variables. Table 1 shows the proportion of variance accounted for and standardized regression coefficients for the predictor variables (age and PTA) for the multiple regression analyses predicting colocated and spatially separated thresholds at three RIR conditions.…”

“…One possible explanation of this finding could be that in the ALL and EARLY conditions, the strength of correlation between PTA and SRM was stronger than the correlation between age and SRM. Another possible explanation for the differential contributions of age and PTA to SRM in results could be, as explained in Srinivasan et al (2016), the variability of hearing status of the listeners used in these experiments. PTA being a better predictor of SRM is consistent with the results of Srinivasan et al (2016) and Glyde et al (2013), both of which used listeners varying more substantially in age and PTA than in Gallun et al (2013).…”

“…As aging and hearing loss are not conditions to which listeners can be assigned and often present together, it is important to examine the relative effects of each by testing a sample varying in both age and hearing ability. Often the two cannot be separated completely in the groups of listeners included in the sample, but statistical methods can be used to further examine the differences among groups as was done in Srinivasan et al (2016). Below, we report the results of an examination of spatial release from masking in the presence of full reverberation, early reflections, or late reverberation for listeners varying in age and hearing ability.…”

“…The effects of age on SRM were not statistically distinguishable from the effects of hearing loss in the Marrone et al study, which only examined large spatial separation (690 ). Srinivasan et al (2016) examined SRM for various spatial separations between the target and the maskers in an anechoic listening environment and a) Portions of this work were presented at the 171st Acoustical Society of America meeting, May 2016, Salt Lake City, UT. concluded that aging was the contributing factor predicting SRM at smaller separations whereas hearing loss was the contributing factor at larger separations.…”