Fixed two errors

---> 21 ploc = UF.peakDetection(mX, hN, t)
TypeError: peakDetection() takes exactly 2 arguments (3 given)

---> 37 plt.plot(np.arange(hN), mX, 'r', lw=1.5)
ValueError: x and y must have same first dimension

Fixed a divide-by-zero warning:
  mY = 20*np.log10(abs(Y[:hNs]))

Used non-blocking plot command