iPhone 4 can hear myself talking

[Sprinting Clio]

Hey guys has anyone else had a problem with there iPhone when talking on the phone you can hear yourself talking through the speaker. It's quite annoying

 

[TC.]

Happens a lot speaking to my parents on their cordless phone.

 

[Andy.]

It's a sign your phone is tapped IIRC.

Does it happen all the time or just in one location? Tried the sim in another phone?

 

[SC03OTT]

Mine has done this since I got it. You eventually ignore it.