Abstract
Interactive EC Fitting is an effective method to set the signal processing parameters of a hearing aid optimal to the preference of a user. However, it has problems that uncomfotable sounds are sometimes generated because of the fluctuation of user's evaluation and the evolutionary operations of EC and that the fitting takes a good amount of time due to the requirement of iterative user's evaluation. We thus propose an improved method that automatically evaluates candidate settings using the preference of sound volume apriori given by the user, and presents the user only candidate settings predicted as comfortable. We developed the improved method and conducted simulation-based experiments for examining the optimal number of candidate settings with no user evaluation and the effectiveness of the improved method. Under the condition that the number of candidate settings with user evaluation was fixed as 20, which is generally used in Interactive EC Fitting, the best performance was achieved for the number of candidate settings with no user evaluation of 10 in our experiments. With this number, the improved method significantly reduced the variance of evaluation values, and it is suggested that outliers, i.e., uncomfortable settings, were efficiently reduced. In addition, the improved method significantly accelerated the EC convergence, and the shortening of fitting time was suggested. Our future work will be some practical experiments using human subjects to examine whether the improved method reduce the users' fatigue.
