The "sound" of the brain...?

[aot]

So, as a scientist, I have plenty of geeky friends... and one of them is interested in creating a sound file from the brain waves she records. Essentially, she has a brain wave, and wants to feed it into a sound program to play it as if it were a sound wave.

Does anyone know of a program like this, or possibly a way to do it using python? I only ask here because I don't know of a better forum for this question, and if the answer is available in python I might be able to code something up for her.

Cheers!

[names24]

just curious, whose brain waves has she recorded? I would like to hear my brain sound later if you succeed ;) Cool!!

[scru]

What format are the recorded waves in? A binary stream, or?

[aot]

Ah yes. Technically they record it in analog and convert to digital, so she could theoretically provide either format. Although I don't know the specific file type that she uses, I can find out. At the least it would be possible to take a screenshot of the wave.

[scru]

I don't know of any program that does exactly this, but maybe you can search for one that transforms binary data into a wave file (or at least how). If you're feeling particularly ambitious, you can even write a script that transforms the data from scratch: http://ccrma.stanford.edu/courses/422/projects/WaveFormat/

[sneekula]

Look into Python modules audioop and sunaudiodev
Sun's .au audio file format is rather simple and flexible. Here is an example that vegaseat left some time ago, it shows you how to create an .au files from scratch:

# create a soundfile in AU format playing a sine wave
# of a given frequency, duration and volume
# tested with Python25   by vegaseat     29jan2008

from struct import pack
from math import sin, pi

def au_file(name='test.au', freq=440, dur=1000, vol=0.5):
    """
    creates an AU format audio file of a sine wave
    of frequency freq (Hz)
    for duration dur (milliseconds)
    at volume vol (max is 1.0)
    """
    fout = open(name, 'wb')
    # header needs size, encoding=2, sampling_rate=8000, channel=1
    fout.write('.snd' + pack('>5L', 24, 8*dur, 2, 8000, 1))
    factor = 2 * pi * freq/8000
    # write data
    for seg in range(8 * dur):
        # sine wave calculations
        sin_seg = sin(seg * factor)
        fout.write(pack('b', vol * 127 * sin_seg))
    fout.close()

# test the module ...
if __name__ == '__main__':
    au_file(name='sound800.au', freq=800, dur=2000, vol=0.8)
    
    # if you have Windows, you can test the audio file
    # otherwise comment this code out
    import os
    os.startfile('sound800.au')

I think the webbrowser module allows you to play .au files too.

[Bill Fisher]

..and if you convert to square waves......