Speech-in-noise measures: Variable versus fixed speech and noise levels

Abstract

Objective: The purpose was to determine if speech-recognition performances were the same when the speech level was fixed and the noise level varied as when the noise level was fixed and the speech level varied. Design: A descriptive/quasi-experimental experiment was conducted with Lists 3 and 4 of the revised speech perception in noise (R-SPIN) test, which involves high predictability (HP) and low predictability (LP) words. The R-SPIN was modified into a multiple signal-to-noise paradigm (23- to −1-dB in 3-dB decrements) from which the 50% points were calculated with the Spearman-Kärber equation. Study sample: Sixteen young listeners with normal hearing and 48 older listeners with pure-tone hearing losses participated. Results: The listeners with normal hearing performed better than the listeners with hearing loss on both the HP and LP conditions. For both groups of listeners, (1) performance on the HP sentences was better than on the LP sentences, and (2) the mean 50% points were 0.1 to 0.4 dB lower (better) on the speech-variable, babble-fixed condition than on the speech-fixed, babble-variable condition. Conclusions: For practical purposes the ≤ 0.4-dB differences are not considered noteworthy as the differences are smaller than the decibel value of one word on the test (0.6 dB).

Key Words::

• Auditory perception
• hearing loss
• speech perception
• speech recognition in multitalker babble

Acknowledgements

The Rehabilitation Research and Development Service, Department of Veterans Affairs supported this work through a Merit Review, the Auditory and Vestibular Dysfunction Research Enhancement Award Program (REAP), a Senior Research Career Scientist Award to the first author, and a Career Development Award to the second author. The authors acknowledge the contributions made by to the project by Kelly Watts. Portions of this work were presented at the annual American Auditory Society Conference (Scottsdale, March, 2009). The contents of this paper do not represent the views of the Department of Veterans Affairs or the United States Government.

Notes

1. In this paper, signal-to-noise ratio is abbreviated two ways. When used in conjunction with a decibel value, S/N is used. When used in text, SNR is used.

2. The R-SPIN is available on CD for a nominal charge through the Department of Speech and Hearing Science, the University of Illinois, Champaign, IL 61820, USA.

3. Throughout the manuscript the terms sentences, speech, and words are used interchangeably within the context of the R-SPIN.

Declaration of interest: The authors report no conflicts of interest.