SYSTEM AND METHOD FOR NOISE THRESHOLD ADAPTATION FOR VOICE ACTIVITY DETECTION IN NONSTATIONARY NOISE ENVIRONMENTS

摘要

The system and method of the invention relates to voice detection technologyfor determining instants of time at which a snapshot of noise characteristicsresults in improved adaptation of noise floors used in voice detection. Theapproach is based on the "lower envelope" of the smoothed input signal power.Incorporation of this approach in a simple time domain VAD (Voice ActivityDetector) results in an effective low-complexity system which, on the basis ofsimulations, gives good performance down to SNR values of about 0dB. In theinvention the lower envelope also provides the updated value of the noisethreshold during the presence of speech. The invention can also be embedded inother, more complex (e.g., frequency domain) VADs at low computational cost.