Pilot Experiments with a Reaction Time Audiometer

A versatile computer-based audiometer system is briefly described. A particular feature of the instrument is its ability to measure subject's reaction times and perform forced-choice speech discrimination tests. Three pilot experiments were performed to investigate the variation, causes of variation and possible uses of reaction time measurements. As a normalization experiment, the reaction times of 18 normally hearing adults performing a forced-choice speech discrimination test were measured. Reaction time data corresponded well with earlier measurements using the same speech material. Pure-tone detection tests showed significant reaction time variations at levels up to 45dB above threshold. A short version of the forced-choice word list was used to test a small group of normally hearing and hearing impaired subjects, from comfortable listening level to threshold. Scoring by percentage words correct was found to give non-significant differences over a wide range of listening levels, whereas significant reaction time increases could be measured.