
A query to ask the selected Excitation object for its loudness.
the loudness in sone units.
The loudness is defined as
∫df 2^{(e(f)  40 phon) / 10} 
where f is the frequency in Bark, and e(f) the excitation in phon. For our discrete Excitation object, the loudness is computed as
Δf ∑ 2^{(ei  40) / 10} 
where Δf is the distance between the excitation channels (in Bark).
© ppgb, October 16, 1999