>But the fact remains that somewhere, something must know to give more
>than linear power to the speaker to make something louder to our ears.

That statement is unclear. If you make something louder then the ear hears
it as louder _if_ it is within the detectability range of the ear. The ear
is not a linear device. I suggest that you look at the results of
measurements on the ears called "Equal Loudness Contours". These map the
way the ear behaves at different volumes and frequency. You should be able
to find this information in Audiometric text books.

>I agree it's not the toolbox, but it must be in the hardware unless you
>are saying that to make something twice as loud requires only twice the
>power.

The amplifier is in the hardware. Your program must change the drive signal
(the voltage of the signal) to the power amplifier if twice as loud is what
you are after. Laurent's email showed how to calculate this.

Peter