Factors influencing performance on the modified rhyme test by noise-exposed service members

Abstract

Two speech-in-noise experiments using stimuli from the modified rhyme test (MRT) were conducted on service members (SMs) in conjunction with their annual hearing tests. The first experiment, involving roughly 3200 SMs, compared performance in the standard diotic headphone-presented MRT test to the performance level that could be achieved if the same MRT stimuli were presented from a single wall-mounted speaker in one of two different clinical sound booths. The second experiment, involving roughly 2000 SMs, examined performance in a headphone-presented MRT paradigm where the target talker was presented monaurally and the ITD ofthe masker alternated between −800 μs and + 800 μs at a 4 Hz rate. Pure-tone audiometric thresholds, N0Sπ detection thresholds, and subjective surveys of hearing difficulty and noise exposure were collected for all participants in both studies. The results show that MRT scores and response times both vary systematically with subjective hearing difficulty, suggesting that a composite time-accuracy score might be the most effective way to evaluating performance on the MRT. The results also provide insights into the hearing difficulties frequently experienced by noise- and blast-exposed service members with normal or near-normal hearing thresholds. [The views expressed in this abstract are those of the author and do not reflect the official policy of the Department of Defense or U.S. Government.]