The effect of frequency transposition on the untrained auditory discrimination of congenitally deaf children.

Various frequency lowering schemes have been developed for use with deaf people who have little or no measurable hearing in the high frequencies. In general, results of studies evaluating such schemes have been discouraging, except for studies evaluating a frequency recoding device devised by Velmans (1973a). Previous evaluation studies with this device have demonstrated that FRED transposition can improve the auditory discrimination of certain subjects with sensorineural deafness after training (e.g. Velmans and Marcuson, 1980; Velmans et al., 1982; Velmans et al., 1988). Using selection criteria developed in the 1988 study, the current study evaluated the effect of FRED transposition on the untrained auditory discrimination of eight congenitally deaf students, aged between 7 years 2 months and 14 years 10 months with high frequency hearing losses. Results demonstrated that FRED transposition significantly enhanced the auditory discrimination of consonants in the high speech frequencies for the subject group. This suggests that FRED transposition may produce some benefits in everyday situations even without formal training. Evaluation tests with and without transposition, such as those used in this study, may provide one means of selecting congenitally deaf people who would be likely to benefit from using FRED aids.