CODEWITHSUNDEEP
pythonaudioipythonpyaudio
O.rka
O.rka

Reputation: 30677

Generate series of audio tones using iPython.display.Audio

I would like to generate consecutive audio tones in iPython. I've seen pyo but I can only get it to work in the terminal...I'd prefer to test out compositions in iPython if possible.

I recently found iPython.display.Audio and thought it could be a useful way to generate tones for animations. 

# Generate a sound

from IPython.display import Audio 
import numpy as np

def waveform(freq,sec=1,sample_rate=44100):
    t = np.linspace(0,sec,sample_rate*sec)
    return(np.sin(np.pi*freq*t))

scale =   [440, 493.88, 523.25, 587.33, 659.25, 698.46, 783.99, 880.00]
sample_rate = 44100

Audio(waveform(440,sec=2),rate=sample_rate,autoplay=True)

So this works, it makes a little soundbox GUI that plays my tone. . . but I can't generate multiple tones when I try:

for note in scale:
    Audio(waveform(note,sec=2),rate=sample_rate,autoplay=True)

I'd really like to get iPython.display.Audio to work but I'm open to using other modules if it plays the tones in realtime (instead of just writing to file). I've heard of pyaudio and pygame but I'm not sure if the sounds can be generated on the fly.

Upvotes: 0

Views: 848

Answers (1)

pneumatics
pneumatics

Reputation: 2885

[edit] I realize I misread your question. My original answer was about combining tones, which you may still find useful so I left it below. You need to append your audio vectors to make one long tone, like this:

sequence = np.array([])
for note in scale:
    sequence = np.append(sequence, waveform(note, sec))
Audio(sequence,rate=sample_rate,autoplay=True)

If you want multiple tones to be played at once, keep reading.

Audio waves follow the superposition principle, so the combination of multiple waves is a linear sum of all the parts. This is super cool because it means you can combine multiple sounds by literally summing them, since you already have them in a nice vector form.

sec = 2
chord = waveform(0, sec) # silence
for note in scale:
    chord += waveform(note, sec)
Audio(chord,rate=sample_rate,autoplay=True)

Here's a pretty nice page on superposition of waves as it relates to audio.

Upvotes: 2

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