Dakun Li / Beijing Xiaomi Mobile Software Co., Ltd
Jinyu Li / Beijing Xiaomi Mobile Software Co., Ltd
Automatic Gain Control (AGC) is a common method in digital signal processing, which adjusts the gain automatically according to the input signal amplitude characteristics. Considering that the human ears are very sensitive to low-frequency transient distortion, the dynamic characteristic of AGC, especially the gain smoothness, is essential to control the transient distortion of the processed signal. In this paper, the effect of the gain smoothing mechanism on the transient distortion of the processed signal is investigated, and a measurement method to evaluate the transient distortion by using chord-like signals is presented, which can match the objective test with the subjective hearing sense.