BIT-RATE REDUCTION STRATEGIES FOR NOISE SUPPRESSION WITH A REMOTE WIRELESS MICROPHONE

In single-channel non-stationary noise reduction it is paramount that a good noise reference is available in a timely manner to maintain a high quality speech signal. Using a remote wireless microphone placed close to a noise source, a good estimate of the noise power spectral density (PSD) can be acquired. This estimate, however, needs to be transmitted to the primary microphone for noise reduc-tion. As wireless transmission is power intensive, it is desirable to reduce the bit-rate while maintaining good performance. In this pa-per, we propose techniques such as quantizing, frequency bin club-bing and intermittent PSD transmission to reduce the transmission bit-rate, and investigate their impact on performance. Index Terms — Speech enhancement, noise reduction, wireless microphone, ad-hoc sensor network. 1