Hi it happens loads of times, i always hear like a pop or click when either a switch in the hosue is turned on, or if the central heating boiler is on then goes off, like when a tap is been run :s, why is this happening, anyway that i can stop it?
I used to get the same thing. It's just too much power going through your house i think. I solved it by purchasing a really good power board with ripple protection.
another solution to stop this inteferance would be to install an RCCD (risidual current cicuit device) but not sure which way would be cheaper, bassically an RCCD device is connected to your fusebox / comsumer unit, i think it monitor the 3 connections (live, neutral & earth) and somehow removes interference from accross the connections
