Further to post re pulsatile tinitus. ct brain/cerviacal spine results said carotid arteries in neck much better than should be for age 63. no high b/p zero calcium heart ct no meds required. if move neck to left when lying in bed seems to trigger it?

Thats better information. It is possible that your carotid artery or branches are getting kinked when you turn your head that way. The sound might have a whoosh at the end of the beat. I assume some one listened to your neck/head and moved your head to the triggering position. Vessels get stiffer as we age. Great that you CT CA scan shows none. Not likely to have heart attack-ever.