Speaker and Mic Test Module
Uses DTMF tones to test transmission through an audio circuit.
NOTE: We disallow repeating digits in the DTMF strings to improve robustness of recognition.
DEPENDANCIES: python-numpy sox
To play some tones: ./beep.sh 123
To recognize some tones: TIMEOUT=5 ./hear.sh 123
Returns 0 on recognition, 1 on timeout.