Still nobody using voice inversion?

Post by **CAPTLPOL** » Tue Sep 30, 2003 8:47 am

I asked about someone using voice inversion with IMBE CAI digital. No one had tried it. I am wondering if anyone has tried it as of yet. My county has not gone to digital yet, however, an area county is digital. I guess I need to get a radio from Nick and give it a shot.

ASTRO_25 · Post by **ASTRO_25** » Tue Sep 30, 2003 10:49 am

Post by **Wowbagger** » Tue Sep 30, 2003 1:11 pm

Voice inversion on a vocoded system "would be bad". The vocoder is designed to handle normal voice- like signals, and a frequency inverted voice signal wouldn't match anything in the vocoder codebook - in other words what came out the other end wouldn't remotely resemble what went in.

Furthurmore, why would you put a system like voice inversion on a system that already supports DES and AES encryption? Voice inversion is trivially weak and easy to crack. While single DES isn't terribly hard to crack IF YOU ARE THE NSA, it is WAYYYYY more difficult to crack for the average user than voice inversion.

And of course, using 256 bit AES encryption will pretty much keep anybody from cracking your system - at those key lengths the way you "crack" them is to break into the guy's shop and steal his key fill device.

Post by **CAPTLPOL** » Tue Sep 30, 2003 2:07 pm

Lindsay said: Why?

I say why not. It would keep those in scannerland perplexed. I was thinking of a low cost solution. I know how easy it is to break voice inversion. A FRS voice inversion retransmitted could bust voice inversion, not to mention the Ramsey kit.

mancow · Post by **mancow** » Tue Sep 30, 2003 2:26 pm

I don't think it's as easy as some say as long as it's rolling code. That's what we use and it seems it would take some amount of work.

mancow

Post by **CAPTLPOL** » Sun Dec 23, 2007 11:59 pm

So has anyone tried voice inversion on digital?

libuff · Post by **libuff** » Mon Dec 24, 2007 4:15 am

CAPTLPOL wrote:So has anyone tried voice inversion on digital?

i think the general consensus is, it wount work.. the vocoder doesn't just blindly code voice, it compares it to a know type of sound, voice, as opposed to sirens, air conditioning, wind, etc.. im not exactly sure what IMBE filters out, but i do know, i work on a system where one particualr channel is mixed mode, and when someone is in analog, i hear everything, the am/fm radio in the car, the noise of the wind, etc. when the go digital, i ONLY hear them.

pretty much the same reason u can't do QC or DTMF on a IMBE.

Post by **akardam** » Mon Dec 24, 2007 8:14 am

Question has been answered.

Still nobody using voice inversion?

Still nobody using voice inversion?

Re: Still nobody using voice inversion?

Re: Still nobody using voice inversion?

Re: Still nobody using voice inversion?