[plug] slowdown probs

[garry]

I haven't seen the reference from the 80's mentioned, but from my electronics 
days...

The reason that a sample rate of 44khz is used is that to sample a signal, 
the sample rate must be at least twice the highest frequency to be recorded. 
That means that even 2.001 times the top frequency would do it. 

An upper limit of ~20 khz is heard by young children. As we are likely to 
experiment with industrial noise, mowers, mufflers and Deep Purple, it is 
pretty much certain that this won't get any better....

So 2 X 20 Khz = 40 kHz, and then a bit, = ~44khz. I think it was Sony who 
developed the CD, and they decided on that.. (I'll stand correcting on the 
decision bit)..

I had my hearing tested in my 20's, and I couldn't hear much past 16kHz.

I haven't thought about why mp3 goes up to such high sample rates, maybe the 
reconstructed audio from digital sources needs a higher rate due to  it not 
being an original analog signal. FK.

Garry.

On Thursday 23 August 2001 11:10, John Knight wrote:
> To all those of you that are thinking that the human ear can only hear 44
> khz, you're wrong. This was what was found in the 80's when CD audio was
> being developed but has been proven to be incorrect in the last few years.
> What the scientists at the time didn't account for was that the inner-ear
> can make out some more frequencies too.
>
> This spurred on technologies like the Sony Super CD and eventually DVD
> audio which runs 48 khz.