Perceptual separation of sensorineural hearing loss and auditory neuropathy spectrum disorder.

OBJECTIVES/HYPOTHESIS The present study aimed to examine whether the response patterns to the chimeric lexical tone tokens, combined with their pure tone audiometry (PTA) results, could separate listeners with sensorineural hearing loss (SNHL) from listeners with auditory neuropathy spectrum disorder (ANSD). STUDY DESIGN Case-control study. METHODS Forty-three SNHL subjects and 46 ANSD subjects participated in a Mandarin lexical tone perception test using original and chimeric tone tokens. Ten sets of monosyllables, with four tone patterns for each, were processed through a 16-channel chimeric synthesizer in which a temporal envelope (E) from a monosyllabic word of one tone was paired with a fine structure (FS) from the same monosyllable of other tones. RESULTS Significantly negative correlations were present between tone perception scores and PTA0.5-4 kHz for both SNHL (P < 0.001) and ANSD (P < 0.001) subjects. Overall, 72.4%, 66.4%, and 46.3% of the tone responses were consistent with FS for the SNHL subjects with mild, moderate, and severe degree of hearing loss, respectively; and 28.4%, 23.1%, and 22.7% were consistent with FS for the ANSD subjects, with the equivalent degree of hearing loss. Similarly, 17.6%, 24.2%, and 37.7% of the tone responses were consistent with E for the SNHL subjects with mild, moderate, and severe degree of hearing loss, respectively; and 45.5%, 44.3%, and 36.5% were consistent with E for the ANSD subjects. CONCLUSION Subjects with SNHL and ANSD may be separated by representing their FS- and E-consistent tone responses as a function of their pure-tone hearing thresholds. LEVEL OF EVIDENCE 3b. Laryngoscope, 126:1420-1425, 2016.