Thresholds of aural overload, word discrimination in noise, and the "fragile ear"

This study examined the relationship between two previously proposed measures of the fragile ear, the aural overload test and word discrimination score in noise. Ten normal-hearing young adults served as subjects. Aural overload thresholds were determined for fundamental frequencies of 500, 1000, and 2000 Hz. Word intelligibility in noise was assessed with tests using an open response-set (Northwestern University Auditory Test No. 6) and closed response-set (Modified Rhyme Test) at a variety of primary-to-secondary ratios. Results revealed a lack of correlation between threshold of overload and word discrimination in noise at unfavorable primary:secondary ratios for both tests(-6 and 0 dB for the NU-6' s and -12 and -6 dB for the Modified Rhythm Test). Significant correlations (p less than 0.05) were achieved, however, with both word discrimination tests when administered at the more advantageous primary:secondary ratios.