Givent a audio.wav recording with silence at both start and end for at least 1second...
How to denoise with SOX ?
# sox in.ext out.ext trim {start: s.ms} {duration: s.ms}
sox audio.wav noise-audio.wav trim 0 0.900
sox noise-audio.wav -n noiseprof noise.prof
sox audio.wav audio-clean.wav noisered noise.prof 0.21
According to source :
Change 0.21 to adjust the level of sensitivity in the sampling rates (I found 0.2-0.3 often provides best result).