This is not easy. Look up "Fletcher-Munson curve" or "constant-loudness
curve" in a book on psychoacoustics. The nonlinearity of loudness changes
with loudness, too. That's why there's a "loudness" knob on most stereo
preamps or receivers.

-----Original Message-----
From: Rosati 
To: csound@maths.ex.ac.uk 
Date: Monday, March 15, 1999 4:31 PM
Subject: Balancing loudness


>Greetings-
>
>If, for example, a sine tone was gliss. from 64 to 20000 cps at a constant
>amplitude, it  appears to get louder as the pitch increases. Does anyone
>know what is the easiest way to balance this so that loudness remains
>constant across the frequency spectrum?
>
>thanks,
>
>dante
>