NOISE CUT-OFF DEVICE EXCITED BY DETECTION OF SPEECH ACTIVITY

摘要

FIELD: radio engineering. SUBSTANCE: proposed device is intended for improvement of sound quality in receiver of digital honeycomb radio system. Detector of speech activity uses estimation of energy to detect presence of speech in received speech signal under operational mode in presence of noise. When there is no speech system attenuates signal and introduces white noise with filtered lower frequencies. In addition there is used set of high-pass filters to filter received signal on basis of level of background noise. This filtration of higher frequencies is applicable to signal independent of presence of absence of speech component in signal. Thus combination of signal attenuation with introduction of white noise with filtered lower frequencies during periods of absence of speech together with filtration of higher frequencies of signal improves quality of sound when speech which was coded under mode of operation in presence of noises is decoded. EFFECT: improved quality of sound.