You couldn't be bothered to tell us WHICH Toshiba TV Model you are having problems with, but in the baisis of what you HAVE told us, the problem may be common.
See here:
http://forums.digitalspy.co.uk/showthread.php?t=243226
http://www.tv-forums.com/forum/TV_Equipment_C4/TV_Repair_Forum_F3/Toshiba_TV_sound_randomly_goes_off_for_short_periods_P82907/
https://uk.answers.yahoo.com/question/index?qid=20131220115421AAjiGdW
But of course, you'll have seen those when you did a search to help your self before coming here asking others to do it for you.
XXX, December 2015
