Array microphone device and gain control method

摘要

The array microphone device has a microphone array composed of a plurality of microphone units, having a signal input section for inputting a signal from the microphone units to be corrected as a signal to be corrected; a reference signal input section; a gain variable section for making the levels of the signal to be corrected and the reference signal equal; and a gain control section. The gain control section includes a high-speed gain update section for changing the gain with a first amount of change per unit time upon time elapsed since the array microphone device is starting-up being below a predetermined period of time; and a low-speed gain update section for changing the gain with a second amount of change per unit time upon the elapsed time being above the predetermined period of time, the second amount of change being smaller than the first amount of change.

主权项

1. An array microphone device having a microphone array composed of a plurality of microphone units, comprising:
a to-be-corrected signal input section configured to input a signal from a microphone unit to be corrected out of the plurality of microphone units as a signal to be corrected; a reference signal input section configured to input a reference signal; a gain variable section configured to amplify or attenuate the signal to be corrected so that a level of the signal to be corrected and a level of the reference signal is substantially equal to each other; and a gain control section configured to control a gain at the time of amplifying or attenuating the signal to be corrected, wherein: the gain control section includes: a first gain update section configured to change the gain with a first amount of change per unit time upon time elapsed since the array microphone device is starting-up being below a predetermined period of time; and a second gain update section configured to change the gain with a second amount of change per unit time upon the elapsed time being above or equal to the predetermined period of time, the second amount of change being smaller than the first amount of change, wherein the gain control section changes the gain by the first gain update section if a sum of the level of the signal to be corrected and the level of the reference signal is above the predetermined value and the time elapsed since the sum went above the predetermined value is below the predetermined period of time, and the gain control section changes the gain by the second gain update section if the sum is above the predetermined value and the time elapsed since the sum went above the predetermined value is above or equal to the predetermined period of time.