Are you want to Know How to remove one or all auto-complete text entries in Chrome? if your answer is yes, then you’re in right place. In this short post, I will show you a very easy trick. By using this trick you know how to make a machine “blank screen” for a period of time (as a penalty) if certain noise levels are reached?
sox from SoX to analyze a short audio sample:
sox -t .wav "|arecord -d 2" -n stat
-t .wav we specify we process the wav type,
"|arecord -d 2" executes the
arecord program for two seconds,
-n outputs to the null file and with
stat we specify we want statistics.
The output of this command, on my system with some background speech, is:
Recording WAVE 'stdin' : Unsigned 8 bit, Rate 8000 Hz, Mono Samples read: 16000 Length (seconds): 2.000000 Scaled by: 2147483647.0 Maximum amplitude: 0.312500 Minimum amplitude: -0.421875 Midline amplitude: -0.054688 Mean norm: 0.046831 Mean amplitude: -0.000044 RMS amplitude: 0.068383 Maximum delta: 0.414063 Minimum delta: 0.000000 Mean delta: 0.021912 RMS delta: 0.036752 Rough frequency: 684 Volume adjustment: 2.370
The maximum amplitude can then be extracted via:
grep -e "RMS.*amplitude" | tr -d ' ' | cut -d ':' -f 2
We grep for the line we want, use tr to trim away the space characters and then cut it by the : character and take the second part which gives us 0.068383 in this example. As suggested by comments, RMS is a better measure of energy than maximum amplitude.
You can finally use bc on the result to compare floating-point values from the command-line:
if (( $(echo "$value > $threshold" | bc -l) )) ; # ...
If you build a loop (see Bash examples) that calls sleep for 1 minute, tests the volume, and then repeats, you can leave it running in the background. The last step is to add it to the init scripts or service files (depending on your OS/distro), such that you do not even have to launch it manually.