RNNoise is a compact, open-source recurrent neural network for real-time noise suppression, designed to be light enough to run frame by frame on an ordinary CPU. It combines classic signal-processing structure with a small RNN that estimates how much of each frequency band is speech versus noise, then attenuates the noise while preserving the voice. Its efficiency and permissive licence made it a common baseline in open-source voice stacks and a popular building block for plugins and embedded systems. It won't match the heaviest commercial or GPU models on extreme noise, but for the cost — a few percent of a CPU core — it removes a remarkable amount of steady and intermittent background sound.
