Reaction Time as a Measure of Threshold and Suprathreshold Hearing. II. Subjects with Impaired Hearing

Abstract

Reaction time has been used as a measure to evaluate hearing and hearing changes associated with drugs, lesions, and noise exposure. In this paper, experimentally produced hearing changes in monkeys are compared to hearing changes in man. Reaction time and other psychoacoustic measures are compared in human subjects. Temporary hearing loss was produced in monkey and man by exposure to pure tones one-half octave below a selected test frequency. Exposures produced threshold shifts and changes in the intensity function which were similar for both man and monkeys. These changes are similar to those reported by Moody [Adv. in Otorhinolaryngol. 20, (1973)] for the monkey and are comparable to hearing changes in human subjects with clinically diagnosed sensorineural hearing loss and recruitment. They can be contrasted to the hearing loss seen in man and monkey with a conductive loss. In the humans, the changes in hearing reflected in reaction time performance are similar to those observed in loudness matching studies in the laboratory and in the clinic. The results confirm that the reaction time task is indeed applicable to the experimental study of conductive and cochlear hearing losses and to physiological studies of threshold and loudness coding. [Work supported by PHS Grants NS 08181, RR 00166, NS S0637, and NS 05082.]