Patent ID: 9666206
Date: 2017-05-30
CPC Classifications: G10L

Claim:
1. A method comprising: attenuating noise by electronic circuitry components performing operations comprising: receiving a first voltage signal that represents speech and the noise, wherein the noise includes directional noise and diffused noise; receiving a second voltage signal that represents the noise and leakage of the speech; in response to the first and second voltage signals, generating a first channel that represents the speech and the diffused noise while attenuating most of the directional noise from the first voltage signal, and generating a second channel that represents the noise while attenuating most of the speech from the second voltage signal; in response to the first and second channels, generating at least N frequency bands of an output channel that represents the speech while attenuating most of the noise from the first channel, wherein N is an integer number >3; and, in response to the output channel, outputting an electrical signal to communicate the speech while attenuating most of the noise from the first channel; wherein k is an integer number that ranges from 1 through N, and wherein generating each (“kth”) of the N frequency bands of the output channel for a time frame n includes: within the kth frequency band of the output channel, determining an estimated a priori speech-to-noise ratio (“SNR”) of the kth frequency band by computing a ratio between: an estimated power of a clean version of the speech within the kth frequency band for an immediately preceding time frame n−1; and a power of the noise within the kth frequency band for the immediately preceding time frame n−1; within the kth frequency band of the output channel, determining an a posteriori SNR of the kth frequency band by computing a ratio between: a power of a noisy version of the speech within the kth frequency band for the time frame n; and a power of the noise within the kth frequency band for the time frame n; in response to the kth frequency band's estimated a priori SNR and the kth frequency band's a posteriori SNR, determining a gain of the kth frequency band for the time frame n; and generating the kth frequency band of the output channel for the time frame n in response to multiplying: the kth frequency band's gain for the time frame n; and the kth frequency band of the output channel for the time frame n.