The interpretation of speech reception threshold data in normal-hearing and hearing-impaired listeners: steady-state noise

• Published in: The Journal of the Acoustical Society of America Vol. 130; no. 5; p. 2987
• Main Authors: Smits, Cas, Festen, Joost M
• Format: Journal Article
• Language: English
• Published: United States 01.11.2011
• Subjects: Acoustic Stimulation; Adult; Analysis of Variance; Auditory Perception; Auditory Threshold; Case-Control Studies; Female; Hearing - physiology; Hearing Disorders - physiopathology; Hearing Disorders - psychology; Humans; Male; Mathematical Computing; Middle Aged; Noise - adverse effects; Perceptual Masking; Persons With Hearing Impairments - psychology; Recognition (Psychology); Speech Acoustics; Speech Intelligibility; Speech Perception; Speech Reception Threshold Test
• ISSN: 1520-8524
• DOI: 10.1121/1.3644909

Speech-in-noise-measurements are important in clinical practice and have been the subject of research for a long time. The results of these measurements are often described in terms of the speech reception threshold (SRT) and SNR loss. Using the basic concepts that underlie several models of speech recognition in steady-state noise, the present study shows that these measures are ill-defined, most importantly because the slope of the speech recognition functions for hearing-impaired listeners always decreases with hearing loss. This slope can be determined from the slope of the normal-hearing speech recognition function when the SRT for the hearing-impaired listener is known. The SII-function (i.e., the speech intelligibility index (SII) against SNR) is important and provides insights into many potential pitfalls when interpreting SRT data. Standardized SNR loss, sSNR loss, is introduced as a universal measure of hearing loss for speech in steady-state noise. Experimental data demonstrates that, unlike the SRT or SNR loss, sSNR loss is invariant to the target point chosen, the scoring method or the type of speech material.