Audio Noise Measurement

A work-in-progress since 2009 to develop the history of the measurement of low-level noise in terms of how it is perceived by humans, in particular regarding producing a single number to indicate this level or perception in the context of listening to music.

This concerns the CCIR 468 and related technical standards, which are widely regarded as being the best approach to measuring self-noise in microphones and other items of audio equipment.  However, it is not widely used at present.  Consequently, self-noise of microphones is typically quoted in units of dBA - which uses a frequency filtering and signal detection system which does not adequately match human perception.  Therefore, it is impossible to reliably compare the self-noise of most microphones from their published specification.  Widespread adoption of CCIR 468 or the like would resolve this problem.

My plans for an open-source or public-domain command-line program to read a .WAV file and produce noise measurements according to the three techniques mentioned above.

I haven't made any concrete progress on this.  Please see the history page for the background on this.