Modified segmental signal-to-noise ratio reflecting spectral masking effect for evaluating the performance of hearing aid algorithms

Abstract

Most traditional objective indices don't distinguish between a real sound and a perceived sound, and therefore, these indices have limitations in regard to the evaluation of the real effect of an algorithm under investigation on the auditory perception of a hearing-impaired person. Though several objective indices, such as perceptual evaluation of speech quality (PESQ) and composite measurements, that reflect the psychoacoustic factors were already in use, it is helpful to develop more objective indices that take into account human psychoacoustic factors in order to accurately evaluate the performance of hearing aid algorithms. In this study, a new objective index that reflects the spectral masking effect into the calculation of the conventional segmental signal-to-noise ratio (segSNR) was proposed. The performance of this index was evaluated by analyzing the correlation of the result and (1) the mean opinion score and (2) the speech recognition threshold tests of 15 normal-hearing volunteers and 15 hearing-impaired patients. The correlation values of the proposed index were relatively high (0.83-0.97) across various ambient noise situations. Based on these experimental results, the proposed index has the potential to be widely used as a measuring index for the performance evaluation of various hearing aid algorithms prior to conducting clinical experiments.