Speech audiometry has long been a component of a thorough audiological examination. The speech recognition threshold (SRT) measurement is perhaps the most widely used measurement in speech audiometry. For decades, researchers and clinicians have worked to create and fine-tune word lists that for use in SRT testing; their aim being to improve the accuracy for classifying a client's ability to hear and comprehend speech. Experts in the field have agreed to follow four tenets of speech audiometry when selecting word sets. This study examined whether improvement to stimulus lists for SRT measurement could be made in regards to the tenet of homogeneity with respect to audibility if the slope of the psychometric function were a selection consideration. The study was performed with the hypothesis that steeply sloping words would significantly reduce the number of words needed to obtain the SRT. Three word lists, all recorded by a female talker, comprising of steeply sloping words, medium sloping words, and shallow sloping words, were used in the study. Participants with normal hearing between the ages of 18 and 30 years provided data that was used to calculate SRT measurements for all three lists from each ear. The results showed a significant difference in the number of words needed to obtain the SRT when comparing the steep and shallow word sets and the shallow and medium word sets. Steeply sloping words required fewer words to obtain the SRT, M = 17.02. Shallow sloping words required the most words, M = 18.88, amounting to a difference of 1.86 words. While statistically different, a reduction by fewer than 2 words during the course of SRT testing will not equate to a substantial saving of time for the clinician. For clinical application, the slope of the psychometric function of the words used in SRT measurement need not be a primary consideration when developing stimulus lists.



College and Department

David O. McKay School of Education; Communication Disorders



Date Submitted


Document Type





psychometric function of slope, speech recognition threshold, speech audiometry