new_contents: import numpy as np
  import matplotlib.pyplot as plt
  import scipy.io.wavfile as wav
  
  
  
  
  data = wav.read("data/test.wav")
  
  print data
  
  sampleRate = float(data[0])
  
  audio = np.array(data[1], dtype=float)
  
  
  aud1 = audio.T[0].T
  aud2 = audio.T[1].T
  print aud1.shape
  freq = np.fft.rfftfreq(aud1.size, d=1./sampleRate)
  fft1 = np.fft.rfft(aud1)
  fft2 = np.fft.rfft(aud2)
  
  fft1[1000:] *= 0.5
  fft2[1000:] *= 0.5
  
  ifft1 = np.fft.irfft(fft1)
  ifft2 = np.fft.irfft(fft2)
  
  
  print fft1.shape
  print freq.shape
  
  plt.subplot(221)
  plt.plot(aud1)
  plt.subplot(222)
  plt.plot(aud2)
  plt.subplot(223)
  plt.plot(ifft1)
  plt.subplot(224)
  plt.plot(ifft2)
  plt.show()
  
  print ifft1.size
  out = np.int16(np.column_stack((ifft1, ifft2)))
  wav.write("out.wav",sampleRate, out )
  
subject: add an audio test with fft low pass filter