DISTORTION-PRODUCT EMISSIONS IN NORMAL-HEARING AND LOW-FREQUENCY HEARING-LOSS CARRIERS OF GENES FOR WAARDENBURGS-SYNDROME

Eight patients with Waardenburg's syndrome (WS) with normal hearing an d 3 additional patients exhibiting a low-frequency hearing loss were t ested for the level of the acoustic distortion product 2f1-f2 by means of the Otodynamics Distortion Product Analyser (ILO92). Wide notches in distortion product otoacoustic emissions (DPOAEs) between 1,000 and 3,000 Hz were found in 7 (12 ears, 87.5%) examined patients with norm al audiograms, which was a significantly higher rate than that found i n the control group (10%). The 3 patients with low-frequency hearing l oss gave a consistent pattern in audiometric configuration shown by bo th pure tone audiograms and DPOAEs. It is concluded from these initial results that DPOAEs may be a useful approach to identifying subclinic al pathologic aberrations in the inner ear in WS patients, and may be a predictor of low-frequency sensorineural hearing loss.