Separating multiple audio signals recorded as a single mixed signal
AssigneeMitsubishi Electric Research Lab, Inc.
InventorsBhiksha Ramakrishnan, Aarthi M. Reddy
Life of this patent
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Abstract
A method according to the invention separates multiple audio signals recorded as a mixed signal via a single channel. The mixed signal is A/D converted and sampled. A sliding window is applied to the samples to obtain frames. The logarithms of the power spectra of the frames are determined. From the spectra, the a posteriori probabilities of pairs of spectra are determined. The probabilities are used to obtain Fourier spectra for each individual signal in each frame. The invention provides a minimum-mean-squared error metho or a soft mask method for making this determination. The Fourier spectra are inverted to obtain corresponding signals, which are concatenated to recover the individual signals.
Claims13
A method for separating multiple audio signals recorded as a mixed signal via a single channel, comprising:
- providing a mixed audio signal input via a microphone;
- sampling the mixed signal to obtain a plurality of frames of samples;
- applying a discrete Fourier transform to the samples of each frame to obtain a power spectrum for each frame;
- determining a logarithm of the power spectrum of each frame;
- determining, for pairs of logarithms, an a posteriori probability;
- obtaining, for each frame and each audio signal of the mixed signal, a Fourier spectrum from the a posteriori probabilities;
- inverting the Fourier spectrum of each audio signal in each frame;
- concatenating the inverted Fourier spectrum for each audio signal in each frame to separate the multiple audio signals in the mixed signal;
- and
- outputting said separated multiple audio signals.
A method for separating multiple audio signals recorded as a mixed signal via a single channel, comprising:
- providing a mixed audio signal input via a microphone;
- sampling the mixed signal to obtain a plurality of flames of samples;
- applying a discrete Fourier transform to the samples of each frame to obtain a power spectrum for each frame;
- determining a logarithm of the power spectrum of each frame;
- determining, for pairs of logarithms, an a posteriori probability;
- determining a soft mask of each logarithm;
- obtaining, for each frame and each audio signal of the mixed signal, a Fourier spectrum from the a posteriori probabilities, and in which the soft mask is applied to a corresponding logarithm of the power spectrum to obtain the Fourier spectrum;
- inverting the Fourier spectrum of each audio signal in each frame;
- concatenating the inverted Fourier spectrum for each audio signal in each frame to separate the multiple audio signals in the mixed signal;
- and
- outputting said separated multiple audio signals.
Dependencies are inferred from the claim text.