Sound eXchange: play, record and convert audio files. Audio formats are identified by the extension.

# To merge two audio files into one:
sox -m input_audiofile1 input_audiofile2 output_audiofile

# To trim an audio file to the specified times:
sox input_audiofile output_audiofile trim start end

# To normalize an audio file (adjust volume to the maximum peak level, without clipping):
sox --norm input_audiofile output_audiofile

# To reverse and save an audio file:
sox input_audiofile output_audiofile reverse

# To print statistical data of an audio file:
sox input_audiofile -n stat

# To increase the volume of an audio file by 2x:
sox -v 2.0 input_audiofile output_audiofile