Parameter optimization in time-frequency ε-filter based on correlation coefficient

Time-Frequency ε-filter (TF 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 small stationary noise but also large 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 general. 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 TF ε-filter. We conducted the experiments to compare the value of the correlation coefficient and the mean square error when we change ε value. The experimental results show the applicability of our criterion in parameter setting of ε-filter.