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

Claim 0:
1. A voice activity detection (VAD) device capable of referring to an environment detection result and thereby selecting one of multiple VAD results as a basis for determining whether a voice activity occurs, 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) and thereby obtaining 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 and thereby generating 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);

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