# Cable channel sound contamination

**URL:** <https://boards.straightdope.com/t/cable-channel-sound-contamination/446410>\
**Category:** Factual Questions\
**Created:** [April 22, 2008, 3:59pm UTC](https://boards.straightdope.com/t/cable-channel-sound-contamination/446410 "2008-04-22T15:59:17Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Thinktank](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Thinktank](https://boards.straightdope.com/u/Thinktank)\
**Post date:** [April 22, 2008, 3:59pm UTC](https://boards.straightdope.com/t/cable-channel-sound-contamination/446410/1 "2008-04-22T15:59:17Z")

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Hi,  
The background to this question is that my wife and I are renting a room out of a larger house. On the owner’s side he has installed a set-top box for viewing some channels in HD and has broadband internet as well as Comcast digital voice phone service.

I used to run and hook-up cable myself, so I see no fault in the way the cable is "T"ed off. The modem is on a dedicated leg away from the cable so it can send and receive signal just fine. There is also a powered amp involved, but signals are at acceptable levels for all runs of coax.

What I’m here for is to ask if anyone has had a situation where the audio from one channel is heard in a manner similar to feedback in the audio of the channel you are watching?

It’s not very loud, but say you are watching a drama on TV and two people are talking… so that dramatic pause happens where there is only silence … it’s at **th-at** moment you start hearing William Shatner try to save someone money on a f\*\*\*\*\* hotel room… “mamby-pamby… cupcake… mama’s-boy”… \>sigh\<

Only 2 channels do this with our cable, 1 channel is within 2 channels of the offending audio. The other channel I have not yet found which channel it is that projects it’s audio onto it.

What would be the most likely reason for such a phenomenon? What can be done- besides calling my cable company? I’m already that far. Thanks in advance.

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**Author:** ![Astroboy14](https://avatars.discourse-cdn.com/v4/letter/a/df705f/32.png) [@Astroboy14](https://boards.straightdope.com/u/Astroboy14)\
**Post date:** [April 22, 2008, 4:48pm UTC](https://boards.straightdope.com/t/cable-channel-sound-contamination/446410/2 "2008-04-22T16:48:01Z")

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Possibly some signal ingress from an unshielded cable?

Are the channels that this happens on also broadcast over the air?

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**Author:** ![Thinktank](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Thinktank](https://boards.straightdope.com/u/Thinktank)\
**Post date:** [April 22, 2008, 6:12pm UTC](https://boards.straightdope.com/t/cable-channel-sound-contamination/446410/3 "2008-04-22T18:12:29Z")

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No Astroboy,  
both channels are within the cable TV range only.

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**Author:** ![Astroboy14](https://avatars.discourse-cdn.com/v4/letter/a/df705f/32.png) [@Astroboy14](https://boards.straightdope.com/u/Astroboy14)\
**Post date:** [April 22, 2008, 7:05pm UTC](https://boards.straightdope.com/t/cable-channel-sound-contamination/446410/4 "2008-04-22T19:05:07Z")

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Hmmm… then you got me. We’ve exceeded the limits of my knowledge.

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**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\
**Post date:** [April 22, 2008, 7:39pm UTC](https://boards.straightdope.com/t/cable-channel-sound-contamination/446410/5 "2008-04-22T19:39:20Z")

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I get this exact thing. I have cable TV with a set-top box, but also a regular roof aerial. The volume on cable tends to be lower than with the aerial signal, so I have the TV turned up. During quiet dramatic moments of a film on pay-per-view, I can often hear crowd noise from Match of the Day or some such inappropriate sound. I just put it down to a quirk of my TV. I assume the circuits aren’t sufficiently isolated or something.