Preliminary results of a novel enhancement method for high-frequency hearing loss

In this study, a software program was developed for high-frequency hearing loss subjects that includes a detailed audiogram and novel enhancement methods. The software performs enhancements of the audibility of high-frequency sounds according to the subject's detailed 31-point audiogram. This provides subject-specific gains in the entire frequency spectrum, and especially for high frequencies, of sounds. Amplification, compression, and transposition are the three main processing methods used to obtain the desired enhancements for the subjects. For low frequencies, only the amplification method was used according to the dB value of the input. For mid and high frequencies, the compression and transposition methods were used together. To obtain the preliminary results of the study, 10 subjects were enrolled in a detailed audiogram study for five weeks. In the study, environmental, music, and speech sounds were used. While the perceptual mean performances of the subjects were in the range of 25.33–63.77% in the first week, those values increased to 68.75–95.75% in the fifth week. In particular, all noisy and speech sounds were more significantly identified and understood by the subjects with the enhancement method (from 25.33% to 87.5% and from 42.33% to 90.5%, respectively). Three subjects had dropped out at the end of the study and small number of participants are the limitations of this study; however, as a preliminary result, some ideas can be inferred from the results for a smaller set of subjects obtained in the five weeks of the study. Thus, the reliability of the study needs to be tested with more subjects and a comparison with their own hearing aids should be conducted.