MOTM

Tentochi wrote:

>The switching from the carrier to the NS is performed
on the HP channel only, correct? Just want to make
sure I am not missing anything.<

The HP filter simply provides detection for the switch.  If you 
wanted to vocode the word "shemp," for example, and were using synth 
strings as an input, the vocoder would detect the "sh" and switch to 
internal noise as the input, then would fall back to the synth string 
input for the "emp" portion.

>Is the 12 kHz cut-off based on designs you have seen
or is based on linguist analysis? IOW, how arbitrary
is that point?<

That was off the top of my head, as it has been over 20 years since I 
built a vocoder.  A report I wrote as part of my college graduation 
requirements is around here someplace and would have the correct 
value.  If I find it, I'll send the correct number, but I'm pretty 
sure it would be around 12 kHz.

johnm