[ICOM] IC-718 Speech Processor

[Dick Flanagan]

At 03:39 AM 10/31/2006, William Lambing wrote:
 >Adam ... we've had this discussion prior and I have looked at the data.  The
 >problem is .... 99.9% of the people cannot read and do not care.  I have no
 >problem with your data.  It is those who do not care.

Some of us are really lazy/dense and need to have the facts beat into them.  :)

I remember about ten years ago I was working a gentleman in Australia or 
New Zealand and he was testing a switch-adjustable speech processor he had 
built.  His processor would add speech compression in 3db steps.

He originally called me with no compression at all.  His voice was 
perfectly clear and understandable and I had no difficulty hearing him over 
the typical path noise.  When he then clicked in the first 3db step I was 
astounded!  His voice just rose up out of the noise with an almost 
theater-like presence and it was like he was sitting next to me.

Then he added 3db more and with a total of 6db I could hear a slight 
improvement over the 3db, but nowhere near the dramatic improvement the 
first 3db added.  From that point on additional increases in compression 
gave no discernable improvement until a point was reached at about 12db 
where his signal started to distort.

This made it clear even to a dunderhead like me that 1) compression offers 
a very dramatic improvement in on-the-air readability and 2) more than 6db 
is not needed and can quickly lead to distortion.  More is not better, but 
6db is true magic.

73, Dick
--
Dick Flanagan K7VC NV SM
E-mail: k7vc at arrl.org