Voice detector and a method for suppressing sub-bands in a voice detector

摘要

Embodiments of the present invention relate to a voice detector receiving an input signal that is divided into sub-signals that represent a frequency sub-band. The voice detector calculates, for each sub-band, a signal-to-noise (SNR) value based on a corresponding sub-signal for each sub-band and a background signal for each sub-band. The voice detector also calculates a power SNR value for each sub-band, where at least one of the power SNR values is calculated based on a non-linear function. The voice detector forms a single value based on the calculated power SNR values and compares the single value and a given threshold value to make a voice activity decision presented on an output port.

主权项

1. A voice detector being responsive to an input signal being divided into sub-signals each representing a frequency sub-band (n), said voice detector comprises:
a first input port configured to receive said sub-signals, a second input port configured to receive a background sub-signal based on said sub-signals, at least one microprocessor, a non-transitory computer-readable storage medium, coupled to the at least one microprocessor, further including computer-readable instructions, when executed by the at least one microprocessor, are further configured to:
calculate, for each sub-band, a Signal-to-Noise-Ratio (SNR) value (snr[n]) based on the corresponding sub-signal, and the background sub-signal,provide a non-linear weighting of the SNR value (snr[n]) for each sub-band wherein the voice detector is configured to use a sub-band specific significance threshold value (sign thresh) in the non-linear weighting to selectively suppress sub-bands, and the voice detector adaptively adjusts the sub-band specific significance threshold value based on estimated noise, or background signal condition,calculate a power SNR value for each sub-band from the non-linear weighting of the SNR value (snr[n]) for each sub-band,form a single value (snr_sum) based on the calculated power SNR values,compare said single value (snr_sum) and a given threshold value (vad_thr) to make a voice activity decision (vad_prim) presented on an output port.