Patent ID: 11875779
Assignee: REALTEK SEMICONDUCTOR CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 5:
6. A voice activity detection (VAD) device capable of referring to an environment detection result and thereby selecting one of multiple VAD algorithms, the VAD device comprising:
an environment detection circuit configured to process an audio input signal and thereby generate the environment detection result, the environment detection circuit including:
a signal analysis circuit configured to generate M processed signal(s) of each of L frame(s) according to the audio input signal, wherein the M processed signal(s) are M frequency band signal(s) or M frequency domain signal(s), the M is a positive integer, and the L is a frame number;
an energy variation detection circuit configured to perform a plurality of steps and thereby generate X energy variation value(s) of the L frame(s), wherein the X is equal to a product of the M and the L and the plurality of steps includes:
calculating according to the M processed signal(s) of each of the L frame(s) to obtain X signal energy value(s);
calculating X short-term energy value(s) according to the X signal energy value(s) and a short-term frame number, and calculating X long-term energy value(s) according to the X signal energy value(s) and a long-term frame number;
obtaining X energy correlation value(s) according to the X short-term energy value(s) and the X long-term energy value(s), wherein each of the X energy correlation value(s) is a ratio of one of the X short-term energy value(s) to a corresponding one of the X long-term energy value(s); and
comparing each of the X energy correlation value(s) with an energy threshold to generate the X energy variation value(s); and

a variation information decision circuit configured to process the X energy variation value(s) to generate L energy variation detection value(s), then compare each of the L energy variation detection value(s) with a variation threshold to generate L comparison result(s), and then generate the environment detection result according to the L comparison result(s); and

a voice activity detection and decision circuit configured to select one of the multiple VAD algorithms as an applicable VAD algorithm according to the environment detection result, and further configured to analyze the audio input signal with the applicable VAD algorithm and thereby generate a VAD result as a basis for determining whether a voice activity occurs.