STEPS:

1-RECORD THE NOISE

rec $HOME/noise.wav

2-CREATE THE NOISE PROFILE VIA THIS

sox -c 1 $HOME/noise.wav -n trim 0 2 noiseprof $HOME/speech.noise-profile

3-DENOISE

sox -c 1 INPUTFILE.WAV OUTFILE.wav noisered $HOME/speech.noise-profile VALUE

note : value should be 0-1 default is 0.5

if you use 2 channels you could get sox get this message
22562 Segmentation fault sox \$tempnameaudio \$tempfolder/temp.wav noisered \$HOME/speech.noise-profile \$1
so please make sure you used 1 channel