Digital Trunking System Scanner Voices

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17TLS02

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Hey i was wondering why digital trunking system voices sound not like human voices kind of and analog frequencies sound the exact way there voice sounds if you were talking to the person face to face?
 

DJ11DLN

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Hey i was wondering why digital trunking system voices sound not like human voices kind of and analog frequencies sound the exact way there voice sounds if you were talking to the person face to face?
The trunking part would have little to do with it. Digitizing voice and then decoding it on the other end is an imperfect science and errors occur. So the voices sound muddy or robotic. Also low signal strength can make it worse. Some radios do a better job of it than scanners, and some scanners do a worse job than others. If you can understand most of what is being said, count your blessings.:wink:

With analog, the digital encoding/decoding steps are skipped, resulting in much more realistic audio.
 

gewecke

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The trunked P25 audio on my 197's sounds pretty natural. Nearly as good as my 780. :). 73, n9zas
 

DJ11DLN

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The trunked P25 audio on my 197's sounds pretty natural. Nearly as good as my 780. :). 73, n9zas
Same for my 197 (don't have a 780 to compare), but in comparison to good old analog, there was definitely a learning curve for my ears. Maybe because like the rest of me they aren't what they once were...but there is a difference. Luckily an old dog can occasionally learn a few new tricks.:D
 

BaLa

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I actually think P25 sounds pretty goood on my 436 most of the time.
It's not Analog of course.
Also keep in mind..They mostly don't give a *#$% what it sounds like on OUR Scanners.




Simulcast can be a different story.

LVMPD 700mhz P25 Phase 2
https://clyp.it/moqu1imp
Non simulcast Tower.
Some Units seems to sound worse than others as well.
-
Spokane Reg. Comm System 800mhz P25 Phase 1
https://clyp.it/4jfvjdhv
Non Simulcast Tower

The Scanner is not liking the Simulcast towers on both of these systems...That works for me..
Just Scanning with all Sites Enabled since they're not particularly big systems.



I have been to a few places that had TRBO radios that sounded atrocious (and being very nice)
Guess they get these Shiny new radios spend a ton of money, it sound like a$$ and don't want to spend any more $ to get them setup properly.
 
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wb0wao

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It does depend on a lot of factors as others have stated, another issue is that the average scanner speaker is not all that great - especially those on the hand held scanners. Try using an external speaker designed for communications service and see if that helps.
 

16b

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The answer that nobody has touched on yet is that the digital voice technology you are referring to (I am going to guess you are talking about P25) uses a lossy codec called IMBE to encode and decode voices. A lossy codec compresses the audio to allow it to fit into the narrow bandwidth allotted for radio channels. Your cell phone does the same thing when making a phone call; it just has more bandwidth available, so the voice sounds more natural (though it still doesn't sound exactly like a face-to-face conversation).

Here is information about IMBE and AMBE from the company that created them--DVSI: DVSI Products - Software
 
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