>
> There is a relation between sound pressure level and sound intensity level
> if there is a plain wave (in german "ebene Schallwelle")
>
> L = 20*lg(p/p0) dB = 10*lg(I/I0) dB
>
> p0 := 2E-5 Pa
> I0 := 1E-12 W/m^2
>
> 1W = 1 Nm/s
>
> for coherent sounds one uses the sound pressure
> (coherent sounds: pure tones of the same frequency or sounds from the same
> source)
>
> for pure tones: p(t) = p' cos(wt) , p' sound pressure amplitude
>
so energy of w'th frequency = p' * p'.
Ignoreing the p0 normalization,
db = 20*lg(p') = 10*log(p'*p')
so I think we are ok. (of course, a factor of 2 floating around
in psymodel.c is probably undetectable :-)
Mark
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