Adaptive spatial classifier for multi-microphone systems

摘要

A robust noise suppression system may concurrently reduce noise and echo components in an acoustic signal while limiting the level of speech distortion. The system may receive acoustic signals from two or more microphones in a close-talk, hand-held or other configuration. The received acoustic signals are transformed to cochlea domain sub-band signals and echo and noise components may be subtracted from the sub-band signals. Features in the acoustic sub-band signals are identified and used to generate a multiplicative mask. The multiplicative mask is applied to the noise subtracted sub-band signals and the sub-band signals are reconstructed in the time domain.

主权项

1. A method for performing noise reduction in an audio signal, the method comprising:
executing a frequency analysis module by a processor to transform a primary acoustic signal and one or more secondary acoustic signals to frequency domain sub-band signals, each of the primary acoustic signal and the one or more secondary acoustic signals representing at least one captured sound from a primary microphone and at least one secondary microphone, respectively; forming a noise cancelled sub-band signal from at least one of the frequency domain sub-band signals by performing at least one of subtractive noise cancellation and echo cancellation; deriving a null-processing inter-aural level difference (NP-ILD) feature from the noise cancelled sub-band signal and a raw microphone signal obtained from the at least one secondary microphone; deriving an inter-aural level difference (ILD) feature based on energy outputs of the primary microphone and the at least one secondary microphone; classifying each of a plurality of the frequency domain sub-band signals as speech or noise, based on a set of derived features including the NP-ILD feature and the ILD feature; and performing noise reduction on the plurality of the frequency domain sub-band signals based on the classification.