wavvol modifies volume of .wav file, make it louder or quiet.
Usage is
wavvol level in_file out_file
level is level of amplify or attenuate, in dB. Giving positive value(leading '+' sign is allowed but ommitable) means amplify, makes it louder, negative value(with leading '-' sign) means attenuate, make it quiet.
in_file is input file, out_file is output file. Existance of out_file is not checked, so it is overwriiten silently, without any inquery, even when it already is. Good old '-', the stdout, as out_file is not supported (yet?).
wavvol doesn't have atractive GUI, perhaps never, so must be invoked via command line. And it is written in Python 3, so under Window, command line must be
C:\> python wavvol -20 foo.wav bar.wav
or something.
Under UNIX, Do
$ chmod +x wavvol
just once after you obtained the script, and invoke like
$ ./wavvol -20 foo.wav bar.wav
These command lines does read file named foo.wav, makes it 20dB quieter and write the result into file named bar.wav.
As mentioned above, wavvol is written in Python 3, so its runtime environment is required. No third party module is used, so standard library is enough.
out_file is overwritten when it is already exists.
In case doing amplification giving positive value as level, the result may satulate if it is over gained. When it occurs, wavvol doesn't compress, smoothing nor anything but just clips and distort the result and you see message like
Warning: N samples are clipped.
and exits with 1.