[docs] audioop.rms() docs

[Valentine, Matt]

Hi folks,

There is a slight mis-statement in the audioop docs<https://docs.python.org/3/library/audioop.html> about audioop.rms():

audioop.rms(fragment, width)¶
Return the root-mean-square of the fragment, i.e. sqrt(sum(S_i^2)/n).

This is a measure of the power in an audio signal.

RMS is actually a measure of the amplitude in an audio signal. Power is RMS amplitude squared (RMS without the R). See Wikipedia RMS Amplitude<https://en.wikipedia.org/wiki/Amplitude#Root_mean_square_amplitude>:

  *   "Root mean square (RMS) amplitude is used especially in electrical engineering: the RMS is defined as the square root of the mean over time of the square of the vertical distance of the graph from the rest state"
  *   "the average power transmitted by an acoustic or electromagnetic wave or by an electrical signal is proportional to the square of the RMS amplitude".

The python docs comment could be tweaked as follows:

  *   Simple: "This is the RMS amplitude in an audio signal."
  *   OR: "This is the RMS amplitude in an audio signal. The average power is proportional to the square of the RMS amplitude."

Thanks, -Matt
--
Matt Valentine
Speech Technologies
Garmin International
[auto_oem_sig_96dpi]


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