amp_low = numpy.mean(magnitude[noise_floor:mid_start])
amp_mid = numpy.mean(magnitude[mid_start:high_start])
amp_high = numpy.mean(magnitude[high_start:noise_ceiling])
amp_low = numpy.mean(magnitude[noise_floor:mid_start])
amp_mid = numpy.mean(magnitude[mid_start:high_start])
amp_high = numpy.mean(magnitude[high_start:noise_ceiling])