Audio Noise Measurement
Especially techniques of assigning
a single value to low-level background noise of various types,
to the degree to which humans perceive it and/or find it annoying
Robin Whittle email@example.com March 2012
There are two pages here:
A work-in-progress (I last worked on it
in 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.