log/view microphone sound level to a file?

pauledd · 06-03-2015, 02:03 AM

Hi there
Does anyone know if it is possible to log or output the current sound pressure level of an connected* microphone to the console or an file?

I dont need to record an sound file, just output the sound level without any calibration of the sound pressure scale. I am not aware of any linux tool that can do this.

*via pulseaudio

LADave · 06-03-2015, 02:58 AM

And while doing this, be able to replicate SLM (sound level meter) features such as impulse (35ms), fast (125 ms) and slow (1 s) integration intervals; RMS vs. peak readings; "A", "C" and other weighting schemes? Perhaps even optionally recording audio clips while a trigger volume level is exceeded, or timed sample clips such as one minute every hour? These all seem like candidates for the SOX "swiss army knife of sound" program.

pauledd · 06-03-2015, 11:39 AM

Ok thank you, I have found this way to print some values.

Code:

arecord -r 48000 -qd 1 test.wav && sox test.wav -n stat

Samples read:             48000
Length (seconds):      1.000000
Scaled by:         2147483647.0
Maximum amplitude:     0.320313
Minimum amplitude:    -0.343750
Midline amplitude:    -0.011719
Mean    norm:          0.101320
Mean    amplitude:    -0.009666
RMS     amplitude:     0.119220
Maximum delta:         0.125000
Minimum delta:         0.000000
Mean    delta:         0.017759
RMS     delta:         0.022904
Rough   frequency:         1467
Volume adjustment:        2.909

I couldnt figure out how to pipe directly to sox and I am not sure what value fits most likely the input level meter in audacity. Once I find it I will loop the command and execute it every second and write every value to a file.