On Fri, 14 Sep 2007 16:16:32 -0400, Deek wrote:

Telstar Electronics wrote:
On Sep 14, 6:42 am, Deek wrote:

I understand DISTORTION quite well! I hold an EE degree, managed an EE design
department for 10 years, and served as Chief Engineer on a major Military System
LGM 118A RS/RV.
Speech compression IS IS IS distortion. PERIOD!


I can see why your services were no longer required as Chief
Engineer... thanks for your comments.
www.telstar-electronics.com


I can see why you're more interested in $$ than in accuracy.

If I put a CONSTANT amplitude swept frequency signal, swept from 300 to 3000 Hz,
audio bandwidth, to the input to a transmitting device and I get a VARIABLE
amplitude signal, swept from 300 to 3000 Hz, as the audio output, the device has
DISTORTED the audio.

That's just what speech compressors accomplish.

Every single speech processor is a controlled distortion device. You can market
and do salesmanship all you want. You are still selling a device that distorts
the audio.

Distortion is distortion!!

Far be it for me to in any way shape or form, defend the spamming
hype, marketing what is nothing more than a common IC made for the
purpose, but I'm going to disagree with you to some extent.

By your definition, any bandpass filtering, such as you set up in your
example, would cause "distortion." The transfer function with respect
to frequency is nonlinear, i.e. it's distorted.

Unless you're one of the guys gargling on 14.18 MHZ, I hope you would
not argue that frequency response shaping is not something that we
want to do in (voice) communications systems.

So assuming we agree on that, then like the guy negotiating with the
gal he's trying to bed, we now are just negotiating the price, or
acceptable amount of distortion.

Since the purpose of a communication system (unless you're just
peddling hardware) is to communicate, then one has to look at the
trade-off between distortion and intelligibility. If purposefully
"distorting" the signal by frequency shaping, compression, clipping or
any combination thereof improves the intelligibility at the other end
of the circuit then "distortion" is a good thing, semantics aside.


Wes N7WS