Parameter optimization in ε-filter for acoustical signal based on correlation coefficient

ε-filter can reduce most kinds of noise from a single-channel noisy signal with preserving the signal that varies drastically such as a speech signal. The filter design is simple and it can effectively reduce noise. It can reduce not only stationary noise but also nonstationary noise. However, it has some parameters and we need to set them appropriately based on empirical control. So far, there are few studies to evaluate the appropriateness of the parameter setting of ε-filter. In this paper, we employ correlation coefficient of the filter output and the difference between the input and the filter output as the evaluation function of the parameter setting. We also show the algorithm to set the optimal parameter of ε-filter. We conducted the experiments to compare the value of the correlation coefficient and the mean absolute error when we change the value of ε. The experimental results show the applicability of our criterion in parameter setting of ε-filter.