I use a pair of cordless headphones with a television set. They receive an infra-red signal from a small transmitter plugged into the TV's headphone socket. Occasionally I get an ear-splitting burst of noise lasting for anything up to two or three seconds.
Has anyone any idea what's causing this, and - more to the point - how to get rid of it?
Buy a pair of wireless headphones that use radio-transmission instead of infra-red, as infrared relies on the receiver being inline with the transmitter and the break in the signal could be what giving you the noise. With radiowaves you could even use them in the next room.