[Examinations of distortion product otoacoustic emission in hereditary progressive non-syndromic hearing loss].

OBJECTIVE: To evaluate the hearing function in patients with hereditary progressive non-syndromic hearing loss. METHODS: Distortion product otoacoustic emissions (DPOAE) and pure tone audiometry were carried out in 52 individuals from a family with non-syndromic hearing loss and 15 persons with normal hearing. RESULTS: 1. Sensorineural hearing loss (SNHL) was found in 34 individuals of the family. Among these individuals, DPOAE was totally absent in 15 cases (29 ears) with pure tone average > or = 40 dB and low amplitude or absent middle to high frequencies in 12 cases (23 ears) with high frequency hearing loss but pure tone average < or = 35 dB. 2. Among 21 individuals (42 ears) with normal audiograms, DPOAE presented lower amplitude or absent high and middle frequencies in 12 individuals. CONCLUSION: DPOAE can be used in identification of subclinical pathologic alterations in the cochlea. This would be of particular value in early diagnosis and genetic consultation.