I captured some audio in asterisk using the MixMonitor command, like:
exten => _00.,1,Set(filename=${STRFTIME(${EPOCH},,%Y%m%d-%H%M%S)})
exten => _00.,n,NoOp(${CHANNEL} tried to reach ${EXTEN} logging to wrongnum-${filename})
exten => _00.,n,MixMonitor(wrongnum-${filename})
exten => _00.,n,Goto(wrongnumber,s,1)
But I wanted to listen to the audio. Which turned out to be a bit of searching. In the end I found
the right sox call:
$ play -e signed -r 8000 -b 16 -c 1 keep-20110604-184522.raw
keep-20110604-184522.raw:
File Size: 647k Bit Rate: 128k
Encoding: Signed PCM
Channels: 1 @ 16-bit
Samplerate: 8000Hz
Replaygain: off
Duration: 00:00:40.42
In:58.3% 00:00:23.55 [00:00:16.87] Out:188k [!=====|=====!] Hd:0.0 Clip:0
Converting to a .wav to process in audacity is easy too:
$ sox -e signed -r 8000 -b 16 -c 1 keep-20110604-184522.raw wrongnum-20110604-184522.wav