Objective measures of hearing loss compensation techniques

Many techniques have been developed to compensate for hearing losses. With each new implementation, a subjective test was needed to verify its quality. In this study, objective measures to predict the results of a subjective test have been developed. A database of results from subjective testing based on four compensation techniques, multichannel linear gain, multichannel compression, TVFD [J. C. Rutledge and M. A. Clements, Proc. IEEE ICASSP, 3641–3644 (1991)], and flat gain amplification, were used to develop the objective measures. The measures can be computed directly from the original speech waveform and a speech waveform processed using the compensation technique. Some parameters such as the energy in each band are measured from the original speech waveform and used as the input to a regression analysis model to calculate the coefficients of the model. Then the same type of parameters are measured from the processed speech waveform with some constraints of the hearing loss, such as hearing threshold, incorporated. The objective measures will be used to predict the performance quality of new techniques that are being developed. Subsequent subjective tests will then be used to fine tune the objective measures. It is hoped that the use of these objective measures will streamline the process of bringing new compensation techniques into fruition.