Create a spectrogram of an audio file
The rate 6k option will narrow the frequency range view to the band most sensitive for human hearing. This cuts off frequencies above 3 kHz (half the sample rate of 6k). If you want the full frequency range then leave off the rate 6k option.
sox audio_recording.wav -n rate 6k spectrogram -t "Spectrogram of audio_recording.wav" -o spectrogram_20150531.png # For a white background use '-l' option: sox audio_recording.wav -n rate 6k spectrogram -l -t "Spectrogram of audio_recording.wav" -o spectrogram_20150531.png
Record audio from the microphone
arecord -vv -fdat recording.wav
Using Sox (this works on OS X). This splits on silent gaps:
rec -r 44100 -b 16 -s -p silence 1 0.50 0.1% 1 10:00 0.1% \ | sox -p audio_recording.wav silence 1 0.50 0.1% 1 2.0 0.1% : newfile : restart
Playback audio OX X using Sox
Note that where an output filename is require you may substitute -d or -t coreaudio (for Mac OS X). These seem to be equivalent. The -d option seems to be the more general purpose style since it will automatically pick the correct sound output on a Mac and Linux.
Both examples below play audio and both will automatically detect the audio stream type. The play command is the easier to remember version. You may have special reasons for wanting to use the sox command alternative.
play audio_recording.wav cat audio_recording.wav | sox - -t coreaudio
These are all equivalent using /dev/urandom.
# From a file or device file. sox -t raw -r 44100 -b 16 -e unsigned-integer /dev/urandom -d sox -t raw -r 44100 -b 16 -e unsigned-integer /dev/urandom -t coreaudio # Using a pipe... cat /dev/urandom | sox -t raw -r 44100 -b 16 -e unsigned-integer - -d cat /dev/urandom | sox -t raw -r 44100 -b 16 -e unsigned-integer - -t coreaudio
This uses Sox's built-in noise generator:
play -n synth whitenoise