Psychometric functions for frequency discrimination in spectral regions of normal and impaired sensitivity

Abstract

Both normal‐hearing listeners and listeners with abrupt high‐frequency sensorineural sensitivity losses were trained to asymptotic performance in a 2AFC pure‐tone frequency discrimination task. Stimulus presentation levels were 80 dB SPL and base frequencies for Δf measurements were 300, 1200, and 3000 Hz. A method of constant stimuli was used to obtain psychometric functions and Δf was specified as the 75% correct performance level. Results from the normal‐hearing listeners were consistent with other results recently reported [Wier, et al., J. Acoust. Soc. Am. 61, 178–184 (1977)]. Sensorineural hearing‐loss listeners exhibited frequency discrimination deficits, relative to the normal‐hearing listeners, in frequency regions of sensitivity loss and also in frequency regions of normal sensitivity, even after asymptotic performance levels had been attained. The psychometric functions from the impaired listeners exhibited slope values that were less than those obtained from normal‐hearing listeners. Practice ...