Frequency compression hearing aid for severe-to-profound hearing impairments

(1) Objective: Objective of this study is to know how a frequency compression hearing aid with new concepts is beneficial for severe-to-profound hearing impairments. (2) Methods: Clinical trials of this hearing aid were conducted for 11 severe-to-profound hearing impaired listeners. These 11 wore the frequency compression hearing aid in their daily life and reported subjectively on its performance. Speech recognition tests with five listeners and audio-visual short sentence recognition tests with three listeners were also conducted. This hearing aid can separately adjust the fundamental frequency from the spectral envelope of input speech and can adjust frequency response by use of a post-processing digital filter. (3) Results: Five listeners out of these 11 came to prefer this hearing aid in their daily life and are still wearing it. The results of the speech recognition tests show that the speech recognition scores were not improved for all listeners and the results of the audio-visual short sentence recognition tests do that the audio-visual recognition scores were improved for two listeners. (4) Conclusion: There were some severe-to-profound hearing impaired listeners who preferred the frequency compression hearing aid finally. It is also suggested that the benefits of this hearing aid may be evaluated correctly using not only speech but also visual materials.