J Am Acad Audiol 2020; 31(04): 271-276
DOI: 10.3766/jaaa.19018
Research Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Spatial Release from Masking Using Clinical Corpora: Sentence Recognition in a Colocated or Spatially Separated Speech Masker

Grant King
1  Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC
,
Nicole E. Corbin
2  Division of Speech and Hearing Sciences, Department of Allied Health Sciences, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC
,
Lori J. Leibold
3  Center for Hearing Research, Boys Town National Research Hospital, Omaha, NE
,
Emily Buss
1  Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC
› Author Affiliations
Funding This work was supported by the National Institute of Deafness and Other Communication Disorders (NIDCD, R01 DC000397). [Figure 1] was based in part on a graphic developed by Kellie Halloran.
Further Information

Publication History

Publication Date:
15 April 2020 (online)

Abstract

Background Speech recognition in complex multisource environments is challenging, particularly for listeners with hearing loss. One source of difficulty is the reduced ability of listeners with hearing loss to benefit from spatial separation of the target and masker, an effect called spatial release from masking (SRM). Despite the prevalence of complex multisource environments in everyday life, SRM is not routinely evaluated in the audiology clinic.

Purpose The purpose of this study was to demonstrate the feasibility of assessing SRM in adults using widely available tests of speech-in-speech recognition that can be conducted using standard clinical equipment.

Research Design Participants were 22 young adults with normal hearing. The task was masked sentence recognition, using each of five clinically available corpora with speech maskers. The target always sounded like it originated from directly in front of the listener, and the masker either sounded like it originated from the front (colocated with the target) or from the side (separated from the target). In the real spatial manipulation conditions, source location was manipulated by routing the target and masker to either a single speaker or to two speakers: one directly in front of the participant, and one mounted in an adjacent corner, 90° to the right. In the perceived spatial separation conditions, the target and masker were presented from both speakers with delays that made them sound as if they were either colocated or separated.

Results With real spatial manipulations, the mean SRM ranged from 7.1 to 11.4 dB, depending on the speech corpus. With perceived spatial manipulations, the mean SRM ranged from 1.8 to 3.1 dB. Whereas real separation improves the signal-to-noise ratio in the ear contralateral to the masker, SRM in the perceived spatial separation conditions is based solely on interaural timing cues.

Conclusions The finding of robust SRM with widely available speech corpora supports the feasibility of measuring this important aspect of hearing in the audiology clinic. The finding of a small but significant SRM in the perceived spatial separation conditions suggests that modified materials could be used to evaluate the use of interaural timing cues specifically.

Notes

Portions of this article were presented at the 44th Annual Scientific and Technology Meeting of the American Auditory Society, Scottsdale, AZ, March 2–4, 2017.