Denoising an audio signal using local formant information
A system, method, and computer program product are provided for cleaning an audio segment. For a given audio segment, an offset amount is calculated where the audio segment is maximally correlated to the audio segment as offset by the offset amount. The audio segment and the audio segment as offset by the offset amount are averaged to produce a cleaned audio segment, which has had noise features reduced while having signal features (such as voiced audio) enhanced.
1. A computer-implemented method to reduce noise in audio, wherein the method is implemented in a computer system that includes one or more physical processors and physical electronic storage, the method comprising:
obtaining an audio segment that represents voiced audio, wherein the audio segment includes multiple samples having a sample duration;
determining, by the one or more processors, for individual ones of a set of offsets that delay the audio segment, a correlation between the audio segment and an individual one of a set of delayed audio segments;
selecting a particular offset from the set of offsets, wherein the particular offset corresponds to a greater correlation than other offsets from the set of offsets;
determining a particular delayed audio segment based on delaying the audio segment by the particular offset;
averaging the audio segment and the particular delayed audio segment to obtain a cleaned audio segment; and
outputting the cleaned audio segment.
2. The method of claim 1 , wherein individual ones of the set of offsets span one or more sample durations.
3. The method of claim 1 , further comprising:
determining a second delayed audio segment based on delaying the audio segment by a multiple of the particular offset,
wherein the cleaned audio segment is obtained by averaging the audio segment, the particular delayed audio segment, and the second delayed audio segment.
4. The method of claim 3 , wherein the particular delayed audio segment has a particular correlation with the audio segment, the method further comprising:
determining a second correlation between the audio segment and the second delayed audio segment;
wherein the step of averaging the audio segment, the particular delayed audio segment, and the second delayed audio segment is performed such that the particular delayed audio segment is weighted based on the particular correlation, and further such that the second delayed audio segment is weighted based on the second correlation.
5. The method of claim 1 , wherein the audio segment spans 10 ms, wherein the audio segment includes 80 samples having a ⅛ ms duration.