Measurements of frequency selectivity in listeners with sensorineural hearing loss

Abstract

For listeners with hearing loss due to cochlear damage, we have shown that in frequency regions displaying threshold elevation, there is a marked alteration in the psychophysical tuning curve [J. Acoust. Soc. Am. 58, S71 (A) (1975)]. Of major importance was the observation of a complete disappearance of the low-threshold finely tuned segment in regions of cochlea damage. In the vicinity of the probe, in contrast to the normal tuning curve, the effectiveness of the masker was sharply diminished. The “notch” in the tuning curve has now been confirmed with several listeners having various types of cochlear pathology. Follow-up investigations of the frequency-selective properties of sensorineural listeners were also carried out. In general, the results of experiments examining frequency discrimination and additivity-of-masking are in good agreement with the unusual frequency response revealed by tuning-curve measurements. For example, in regions of threshold elevation, as much as a 10-fold decrease in frequency discrimination was observed. Additivity-of-masking effects also revealed a close correspondence between musket effectiveness and region of cochlear damage. These findings are being used to build a profile of the auditory capacities of listeners with sensorineural hearing loss.