Found in 1 comment on Hacker News
holy_city · 2019-11-10 · Original thread
I wrote this crate [1] as a compressor in Rust which is the opposite of a noise gate, as in gain reduction is applied after a threshold is passed instead of gain reduction applied if it is under a threshold.

If you want a really great approach to noise gating, a fixed threshold is fine but it works better when you apply it to the difference of two envelope followers - one with a short attack, long release (tracks input) and long attack, short release (tracks noise floor). Takes a bit to set it up, but it's a stupid simple way to get extremely effective gating and is easy to fine tune for your application. A lot of Voice Activity Detection (VAD) works this way; it's just a matter of tuning the coefficients and thresholds for your input.

Also useful reference for envelope following are the DAFX text [2], Will Pirkle's textbook on audio in C++ [3] and Zölzer's text [4]





(pdfs can be found around the internet)

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