Simple Matrix creator recorder example - starts recording when it detects some sound (python)

recorder.py

import alsaaudio
import wave
import struct
import time

SAMPLE_RATE = 16000

mic = alsaaudio.PCM(alsaaudio.PCM_CAPTURE, alsaaudio.PCM_NORMAL, device='mic_channel8')
mic.setchannels(1)
mic.setrate(SAMPLE_RATE)
mic.setformat(alsaaudio.PCM_FORMAT_S16_LE)
mic.setperiodsize(160)

output = wave.open('test.wav', 'w')
output.setparams((1, 2, SAMPLE_RATE, 0, 'NONE', 'not compressed'))

# wait a secound, to not catch any unwanted noise e.g. keyboard
time.sleep(1)

print('listening ...')
recording = False
recording_idle = 0

while True:
    length, data = mic.read()
    sound_detected = True if max(struct.unpack('<%dh' % length, data)) > 20000 else False
    if not recording and sound_detected:
        print('started recording - waiting for 2 sec idle')
        recording = True
    if recording:
        if sound_detected:
            recording_idle = 0
        else:
            recording_idle += length
            if recording_idle // SAMPLE_RATE >= 2:
                print('stopped recording')
                break
        output.writeframesraw(data)