[PD] balancing loudness

[Mathieu Bouchard]

On Sun, 2 Oct 2005, Frank Barknecht wrote:

> For that you should use a compressor. While normalization only scales
> the sample so that the sample with the highest amplitude becomes 1,
> compression will give your sound more (or less) energy, that is the
> area below the samples will get bigger overall. Energy is what is
> perceived as loudness.

Not quite. The ear acts as a filter as it is more sensitive for some 
frequencies than others. Acousticians (and industrial security 
technicians) have several kinds of "dB" for that, some relative to average 
hearing level, some relative to a base energy value, etc.

And also, to compute the energy, you have to square the signal before
computing the area, because you want a figure proportional to joules, 
which are watts*secs = ohms*secs*amperes*amperes and the signal itself is 
only proportional to plain amperes.

____________________________________________________________________
Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju
Freelance Digital Arts Engineer, Montréal QC Canada