Effects of Stress, Stop Release, and Familiarization on Speech Recognition Thresholds

Abstract

Objective: This study examined outcomes of common procedural variations of speech recognition threshold (SRT) testing, specifically related to the effects of equal syllable stress, word-final stop consonant release, and priorfamiliarization, with the participants' language status taken into account.Methods: SRTs were obtained from 40 adults with normal hearing. Twenty participants received priorfamiliarization with the spondee list and the other 20 received no prior-familiarization. Repeated SRT tests were administered using three different recordings which varied in syllable stress and word-final stop release patterns. Results:The group with prior-familiarization demonstrated a threshold that was significantly lower than the group without prior-familiarization, by approximately 5 dB HL. Despite the statistically significant effects of equal syllable stress and word-final stop release on SRTs, the magnitude of SRT changes elicited by these acoustic-phonetic variations was only slightly above 1 dB HL. The monolinguals generally outperformed the bilinguals in SRT outcomes with the threshold difference less than 3 dB HL. Conclusion:Findings from the present study suggest that familiarizing listeners with test vocabulary prior to SRT administration should continue to remain an important procedural requirement. Future research addressing the extent to which acoustic-phonetic variations of spondee production affect SRTs in individuals with hearing impairments is warranted.