Hi, these numbers were generated as a result of early digital recording being 
stored on video tape, and thus in video formats  rather than hard drives.
For an explanation including the formula, a little technical and definitely way 
off topic for here which is why I'm posting the link rather than the article 
itself see:
http://www.cs.columbia.edu/~hgs/audio/44.1.html
hth.
Cheers!

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From: "Raymond Grote" <[email protected]>
Sent: Saturday, May 07, 2011 1:38 AM
To: "QWS list" <[email protected]>
Subject: Re: QWS List off topic, audio recording

> This is getting way off topic, but since it started that way I guess it's 
> okay.
> Since we can hear frequencies from 20-20KHZ, we want a sampling rate that 
> can reproduce all those frequencies. A sampling rate can reproduce all 
> frequencies up to half of it. So, a sampling rate of 8KHZ, which is what 
> telephones use,  can only reproduce frequencies up to 4K.
> So, since we want to reproduce all frequencies up to 20K, a rate of 40K at 
> least is required. But, we need to make some room for filters to filter 
> excess frequencies out. If we get over the halfway point of our sampling 
> rate, the higher frequencies get pushed down to lower ones, since the 
> sampling rate isn't high enough to represent them. So, we use a 44.1K 
> sampling rate to give filters some room to filter out those excess 
> frequencies above 20K. I don't know where they came up with that exact rate 
> though.
> And for bits, it's sort of like midi ranges. 16 bits is going to allow more 
> precise control of volume than 8 will, and give a cleaner sound. Just like 
> 128 note velocities will give you more control and smoothness than 32 or 
> something.
> 
> ----- Original Message ----- 
> From: "Alfredo The Writer of music scores" <[email protected]>
> To: "QWS list" <[email protected]>
> Sent: Saturday, May 07, 2011 12:49 AM
> Subject: Re: QWS List off topic, audio recording
> 
> 
>> Um, let me ask more about bit and Hertz. How does changing KHZ affect the 
>> frequency of sound. I mean, if you are at 44000 Hz, you canto hear 
>> anything than if you were in 8000 Hz which spuds like a phone or 
>> something.
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