EARLY DETECTION OF LATE-ONSET AUDITORY DE PRIVATION WITH THE DISTORTED FREIBURG SPEECH TEST

Late-onset auditory deprivation or ''inactivity'' phenomenon has been reported in single cases only because it has not been possible to asse mble a larger number of calculable cohorts for which all necessary det ails concerning individual histories are available. Subjects should no t be older than 60 years of age and should have had asymmetric hearing for at least about 10 years or should have been wearers of monaurally fitted hearing aids. The development of late-onset auditory deprivati on is presented in 6 single cases. All were assessed by the Freiburg s peech discrimination test and the distorted Freiburg speech test, with the latter showing greater sensitivity and variability. It is of spec ial interest that the quotient of distorted speech is reduced in subje cts who have normal hearing in one ear and considerable hearing loss i n the other ear (for example, in the case of unilateral microtia). Thi s effect may be evidence for significant activation of hearing selecti vity developing in the brainstem versus inactivation.