FREQUENCY DISCRIMINATION IN LISTENERS WITH SENSORINEURAL HEARING-LOSS

The difference limen for frequency (DLF) was measured in both ears of 34 hearing-impaired subjects at the octave and interoctave frequencies between 500 and 4000 Hz. In agreement with previous studies of DLF in the hearing impaired, there was only a moderate correlation (0.49) between DLF/F and hearing threshold level (HTL). Correlation and regression analyses at the individual frequencies, however, indicated that DLF/F is much more closely related to HTL at 1000 Hz and above than it is below 1000 Hz. Comparison of the right-left ear differences in DLF and HTL revealed some large DLF differences where there was no HTL difference and some large HTL differences where no DLF difference was found. The lack of a strong relationship between DLF and HTL asymmetries indicates that the structures that limit the DLF and the HTL may, at the same frequency, be damaged differently in each ear of the same subject.