Random Sound FX Using WAV File (Python recipe) by FB36

ActiveState Code (http://code.activestate.com/recipes/578180/)

# Random Sound FX Using WAV File (Multi-Wave)
# http://en.wikipedia.org/wiki/Amplitude_modulation
# http://en.wikipedia.org/wiki/Frequency_modulation
# FB36 - 20150815
import math, wave, array, random
duration = 5.0 # seconds
volume = 100 # percent
n = random.randint(1, 10) # of waves to add together
# frequency of the carrier wave (Hz)
freqCR = [random.randint(500, 3000) for j in range(n)] 
# frequency of the AM wave (Hz)
freqAM = [random.randint(1, 10) for j in range(n)]  
# frequency of the FM wave (Hz)
freqFM = [random.randint(1, 10) for j in range(n)]  
# frequency deviation for FM (Hz)
freqFMDev = [random.randint(100, 400) for j in range(n)]  
phaseCR = [random.random() * math.pi * 2 for j in range(n)]
phaseAM = [random.random() * math.pi * 2 for j in range(n)]
phaseFM = [random.random() * math.pi * 2 for j in range(n)]
# Assumed: ampCR = ampAM = ampFM = 1
data = array.array('h') # signed short integer (-32768 to 32767) data
dataSize = 2 # 2 bytes because of using signed short integers => bit depth = 16
numChan = 1 # of channels (1: mono, 2: stereo)
sampleRate = 44100 # of samples per second (standard)
numSamples = int(sampleRate * duration)
# nSPC: number of Samples Per Cycle
nSPCCR = [int(sampleRate / freqCR[j]) for j in range(n)]
nSPCAM = [int(sampleRate / freqAM[j]) for j in range(n)]
nSPCFM = [int(sampleRate / freqFM[j]) for j in range(n)]
for i in range(numSamples):
    sampleSum = 0
    for j in range(n):
        sample = 32767 * float(volume) / 100
        tCR = math.pi * 2 * (i % nSPCCR[j]) / nSPCCR[j] + phaseCR[j]
        tFM = math.pi * 2 * (i % nSPCFM[j]) / nSPCFM[j] + phaseFM[j]
        tAM = math.pi * 2 * (i % nSPCAM[j]) / nSPCAM[j] + phaseAM[j]
        sample *= math.sin(tCR + math.sin(tFM) * freqFMDev[j] / freqFM[j])
        sample *= (math.sin(tAM) + 1) / 2
        sampleSum += sample
    data.append(int(sampleSum / n))
f = wave.open('RndSoundFX.wav', 'w')
f.setparams((numChan, dataSize, sampleRate, numSamples, "NONE", "Uncompressed"))
f.writeframes(data.tostring())
f.close()