db volume scaling

[Joerg Schumann]

Tim Blechmann:
> some quick comments about, why it sounds `better'. sound pressure level
> [1] correlates with perceived loudness more or less logarithmically. the
> logarithmical dB(SPL) scale is defined with the threshold of the human
> hearing as reference point.
> the range, which is reasonable for listening to music, is possibly
> between 40 and 80 dB(SPL).
>
> [...]
>
> the threshold of loudness perception is about 1 dB, i.e. two sounds with
> a volume difference of less than 1dB are usually perceived a equally
> loud (i don't have any reference on that, but my ears confirmed it,
> after my acoustics professor claimed that in his class). increasing the
> volume by 10dB perceptually doubles the perceived volume.

The German magazine "c't" switched from measuring loudness in sone instead of 
dB(A) some (long) time ago, because that one is better fitted for the human 
ear:
2 sone are twice as loud than 1 sone. 10 sone twice as loud than 5 sone etc. 
This is not the case with dB (see [1] - blue table at the bottom for some 
comparisons). 

A quick test showed: Going down from 100% to 50% in Amarok feels to me like 
it's half as loud. Which is exactly what I would expect from it.

Conclusion: I'd say that the current way to modify the volume is closer to the 
way loudness is represented in sone, i.e. it fits the human ear better than a 
dB scale.


[1] http://www4.computeruniverse.decenturl.com/dba-vs-sone


Regards,
Joerg