[vorbis] what quality ?
morgan at mortsell.com
Sun Apr 21 22:47:41 PDT 2002
> > Above 4kHz? Shouldn't this be below 4kHz?
> No...well, sort of.
> It's all about the difference between the wavelength
> and the distance betwen our ears.
> High frequencies can be more that 360 degrees out of
> phase with respect ot each other so the information
> is useless for positioning. Similarly, very low frequencies
> are also useless because the difference isn't enough.
> There's only a narrow range of frequencies where the
> phase difference is important for positioning, outside
> that range it's more to do with the volume of sound
> reaching each ear (and remember, there's a nice sound
> absorbing mass in between the ears).
> Working out the frequency of a sound which has a
> wavelength the size of your head is left as an
> exercise for the reader.
<p>Humans have different sensitivity to each frequency in the audible spectrum.
It can be meassured by testing the experienced soundlevel at each frequency,
and plot the result in a graph. Humans are most sensitive about 3500 Hz,
which accidently happens to be where the energy peak of most baby cries lies
This frequency response is meassured in decibel and is called A-weighted
This should not be confused with the ability to sense phaseshift at various
"There is always one more bug." - Lubarsky's Law of Cybernetic Entomology
<p><p>--- >8 ----
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