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Author Topic: Echo in international phone calls. Why?  (Read 5698 times)

Offline DoctorBeaver

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Echo in international phone calls. Why?
« on: 10/08/2007 18:08:44 »
I say something and then hear it echoed back to me. I've had that lots of times and it's really annoying. What causes it?


 

Offline chris

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Echo in international phone calls. Why?
« Reply #1 on: 10/08/2007 18:37:10 »
The line is supposed to send you a "clean feed" of the sender's voice at the other end, minus your signal. At your end the phone sends some of your voice back into your earpiece so that you can hear what you are saying.

On domestic short-distance calls, any spill-over (reflection of) audio from the arriving voice back onto the transmit line arrives back at its origin so rapidly that the sound almost maps directly onto the signal being sent to the headset at the other end, so you don't notice any echo. But with long distance calls the time delay means that you hear yourself out of sync with yourself, so to speak (!), so you notice the echo.

Exactly why the audio subtraction of the arriving audio from the sender's voice is not complete I'm not sure - we really need someone from Sonifex (who make the world's best telephone hybrid equipment) to tell us!

Chris
« Last Edit: 10/08/2007 18:43:33 by chris »
 

paul.fr

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Echo in international phone calls. Why?
« Reply #2 on: 10/08/2007 18:53:59 »
Are you using landline or VoIP?
 

Offline DoctorBeaver

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Echo in international phone calls. Why?
« Reply #3 on: 10/08/2007 19:20:57 »
Are you using landline or VoIP?
Landline
 

Offline pete_inthehills

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Echo in international phone calls. Why?
« Reply #4 on: 10/08/2007 22:12:29 »
I get this a lot when talking to the geologists on oil rigs in the north sea.  In the end I'm too busy concentrating on listening for my echo and not paying any attention to what he's saying.

But the rigs aren't that far from Aberdeen....


Pete
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Offline DoctorBeaver

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Echo in international phone calls. Why?
« Reply #5 on: 10/08/2007 23:48:18 »
...In the end I'm too busy concentrating on listening for my echo and not paying any attention to what he's saying.

Pete
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I know exactly what you mean.
 

Offline engrByDayPianstByNight

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Echo in international phone calls. Why?
« Reply #6 on: 13/08/2007 02:43:23 »
There's a piece of equipment in telephone networks called the echo canceler. It's deployed in all the new telephone networks and (I assume) most older networks. The situation Christ described may occur when it fails to function along a voice transmission.
 

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Echo in international phone calls. Why?
« Reply #7 on: 13/08/2007 07:24:40 »
There's a piece of equipment in telephone networks called the echo canceler. It's deployed in all the new telephone networks and (I assume) most older networks. The situation Christ described may occur when it fails to function along a voice transmission.

I know our illustrious leader is special - but I didn't know he was THAT special!
 

Offline engrByDayPianstByNight

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Echo in international phone calls. Why?
« Reply #8 on: 13/08/2007 14:28:26 »
There's a piece of equipment in telephone networks called the echo canceler. It's deployed in all the new telephone networks and (I assume) most older networks. The situation Christ described may occur when it fails to function along a voice transmission.

I know our illustrious leader is special - but I didn't know he was THAT special!

Oops, there goes my butterfinger again.
 

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Echo in international phone calls. Why?
« Reply #8 on: 13/08/2007 14:28:26 »

 

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