combining_mono_audiosegments.py

In [1]: paste
import array
from pydub import AudioSegment
from pydub.generators import Sine, Square

# make two mono sounds (300 Hz tones)
sound1 = Sine(300).to_audio_segment(duration=30000)
sound2 = Square(300).to_audio_segment(duration=30000)

def x():
    sound1_left = sound1.set_channels(2).pan(-1)
    sound2_right = sound2.set_channels(2).pan(+1)

    stereo_sound = sound1_left.overlay(sound2_right)

def y():
    sound1_y, sound2_y = AudioSegment._sync(sound1, sound2)

    # initialize an array, and write the data
    stereo_data = array.array(sound1_y.array_type, sound1_y.raw_data + sound2_y.raw_data)
    stereo_data[0::2] = sound1_y.get_array_of_samples()
    stereo_data[1::2] = sound2_y.get_array_of_samples()

    stereo_sound = AudioSegment(
        data=stereo_data,
        frame_rate=sound1_y.frame_rate,
        sample_width=sound1_y.sample_width,
        channels=2
    )

## -- End pasted text --

In [2]: %timeit x()
10 loops, best of 3: 149 ms per loop

In [3]: %timeit y()
100 loops, best of 3: 10.7 ms per loop