Sinusoidal modeling of spot microphone signals based on noise transplantation for multichannel audio coding

This paper focuses on high-fidelity multichannel audio modeling based on an enhanced adaptation of the well-known sinusoidal plus noise model (SNM). Sinusoids cannot be used per se for high-quality audio modeling because they do not represent all the audible information of a recording. The noise part has also to be treated to avoid an artificial sounding resynthesis of the audio signal. Generally, the encoding process needs much higher bitrates for the noise part than the sinusoidal one. Our objective is to model spot microphone signals using the SNM, by taking advantage of the interchannel similarities to achieve low bitrates. We demonstrate that for a given multichannel audio recording, the noise part for each spot microphone signal (microphone signals before the mixing stage) can be obtained from the noise part of one of the signals (reference, which is fully encoded), by transforming the reference noise part using the noise envelope of each of the remaining signals.