# 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')