Hi, I was watching a time slipped programme last night when suddenly the sound track dropped out and was replaced by a loud drumming noise (think bass version of a fire alarm)this stopped after a bit (20secs or so) and the programme sound returned normally. The noise returned several times during the programme, and if I moved forward of back the sound appeared in the same place in the programme each time.

Never experienced this before, not sure if it was Hummy or a strange fault in transmission. Any ideas?

thanks