I keep getting interference only on one certain persons calls.

Actually yeah i do always have it on speakerphone.I have sensitive ears and can't have phone close to my ear long periods.it only does it so far only when one person calls me.

I don't know, but that happens to me, when I talk to one of my granddaughters. Only her, and she says it only happens when she is talking to me, not to anyone else. It also only happens when we are both in our homes. Could it be something to do with the actual locations?

I'm wondering if it's possible that they or you or a close neighbour has some kind of business machine that creates interference. I think my granddaughters neighbour has a home business and maybe some fax machine or something that could interfere.

You might have a phone off the hook that may cause feedback... Or is it possible that you are using a speaker phone??

You might be getting some type of feedback...