Lg 37 lcd 37lc7d popping sounds and spe...

At times my tv has popping or clicking type sounds that come and go.
This will happen every time I turn my tv on and then it disappears and will happen off and on like when I change the channel or out of the blue. The clicking only last a few seconds each time.
Also the speakers have a high pitched humming sound that is very noticable when the tv is showing a quite scene but it can be heard at all times if you put your ear up to the speakers.