/SYSTEM AND METHOD FOR NOISE REDUCTION IN PROCESSING SPEECH SIGNALS BY TARGETING SPEECH AND DISREGARDING NOISE

摘要

An exemplary noise reduction system and method processes a speech signal that is delivered in a noisy channel or with ambient noise. Some exemplary embodiments of the system and method use filters to extract speech information, and focus on a subset of harmonics that are least corrupted by noise. Some exemplary embodiments disregard signal harmonics with low signal-to-noise ratio(s), and disregard amplitude modulations that are inconsistent with speech. An exemplary system and method processes a signal that focuses on a subset of harmonics that are least corrupted by noise, disregards the signal harmonics with low signal-to-noise ratio(s), and disregards amplitude modulations that are inconsistent with speech.

主权项

1. A method of targeting speech and disregarding noise, comprising:
receiving an input signal, wherein the input signal includes a human speech signal, and noise other than the human speech signal, wherein the input signal has a fundamental frequency; identifying the fundamental frequency of the input signal; identifying one or more harmonics of the fundamental frequency; applying a filter to the fundamental frequency and the one or more harmonics, thereby attenuating energy other than harmonic energy and forming one or more harmonic-only signals; performing an amplitude modulation on the one or more harmonic-only signals, thereby forming one or more amplitude modulated harmonic-only signals; constructing one or more signal-to-noise ratios for the one or more amplitude modulated harmonic-only signals; disregarding one or more signals from among the one or more amplitude modulated harmonic-only signals whose signal-to-noise ratio falls below a threshold amplitude, thereby forming extracted amplitude patterns; applying a bandpass filter to the extracted amplitude patterns, the bandpass filter having a range characteristic of human speech, thereby disregarding one or more signals from among the one or more amplitude modulated harmonic-only signals whose amplitude modulations are inconsistent with the human speech; and outputting a resultant signal.