[vorbis] Re: An introduction to compressed audio with Vorbis

[Graham Mitchell]

> "Each snapshot has a 16-bit number for the "loudness" of the sound,
> meaning that the scale is fairly fine-grained - it ranges from -32,768
> (complete silence during that snapshot) to 32,767 (the loudest volume
> measurable)."
>
> That's not correct.  A single sample is not meaningful by itself; each
> sample merely represents a voltage.  It's the *difference* between
> samples that creates vibrations in a speaker, and therefore sound waves.

        [snip]

> My explanation may leave a bit to be desired; and perhaps this is too
> technical/mathematical for your intended audience.  But the sentence I
> quoted is simply wrong. :-/

Thanks for the correction.  Even as I wrote it, I felt fairly sure that 
-32,768 shouldn't represent silence.

How about: "Each snapshot has a 16-bit number representing the amplitude of 
the sound wave being sampled, which is fairly fine-grained: the scale ranges 
from -32,768 to 32,767.  This wide range allows for even subtle volume
differences to be accurately represented."

Still non-technical, but (hopefully) no longer false.


-- 
Graham Mitchell - computer science teacher, Leander High School
"Compassion should never determine our beliefs about sin; it should 
only determine our response to those who struggle with it."
	-- Harry Schaumberg, "False Intimacy"

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