Frequency compression on speech recognition in elderly people with possible cochlear dead regions

PURPOSE: to evaluate and compare the performance of elderly people with and without cochlear dead regions in speech recognition tests, in silence and in noise, using hearing aids with and without the activation of the nonlinear frequency compression algorithm. METHODS: 38 elderly people with mild to moderate hearing loss and descending configuration, distributed based on the results of the white noise masking technique, in: Group A - 24 elderly people without evidence of cochlear dead regions; Group B - 14 elderly people with evidence of cochlear dead regions. The Lists of Sentences in Portuguese test was applied, seeking the Percentage Index of Sentence Recognition in silence and in noise. The measurements were obtained using the hearing aids without and with nonlinear frequency compression. RESULTS: both Group A and Group B showed statistically significant improvement in silence with the hearing aids with the algorithm; in noise no group presented significant difference without and with frequency compression. Comparing the groups, there was no significant difference in silence without and with frequency compression. In noise without the algorithm there was significant difference, Group B being the better of the two. In noise without frequency compression there was no significant difference. CONCLUSION: in silence, both groups presented significant improvement in performance using hearing aids with frequency compression. In noise, there was no difference between the results without or with frequency compression. Comparing the groups, the measurement obtained in noise with hearing aids without the algorithm was the only one that presented a significant difference, in which the group with cochlear dead regions presented a better performance.