Change the volume of a wav file in python

Question

I have a 2 seconds 16bit single channel 8khz wav file and I need to change its volume.

It should be quite straightforward, because changing the volume is the same as

Answer 1

I wrote a library to simplify this type of thing

You can do that like so:

from pydub import AudioSegment

song = AudioSegment.from_wav("never_gonna_give_you_up.wav")

# reduce volume by 10 dB
song_10_db_quieter = song - 10

# but let's make him *very* quiet
song = song - 36

# save the output
song.export("quieter.wav", "wav")

Answer 2

The code which makes sound louder plus filter low and high frequencies

from pydub import AudioSegment

audio_file = "first.mp3"

song = AudioSegment.from_mp3(audio_file)

new = song.low_pass_filter(1000)

new1 = new.high_pass_filter(1000)

# increae volume by 6 dB
song_6_db_quieter = new1 + 6

# save the output
song_6_db_quieter.export("C://Users//User//Desktop//second.mp3", "mp3")

Answer 3

As you can see in the comments of the question, there are several solutions, some more efficient.

The problem was immediately detected by Jan Dvorak ("the * 5 part is clipping and overflowing") and the straightforward solution was:

s = numpy.fromstring(s, numpy.int16) / 10 * 5

In this case, this solution was perfect for me, just good enough.

Thank you all folks!