When I take my blood pressure manually, I find that I don't always hear the beats right away so I don't have the correct starting number. Can I note the number at which the needle begins moving back and forth or do I have to note the number at which I hear the beats?

cb,

You are describing PRECISELY the reason almost all of us have opted for a self inflation, digital model...you push a button and let the machine do all the work.
Those old sphygmomanometer rigs are best left to the doctors who can make then say any number that suits them and there's nobody to call them on "hearing things." :D

Years ago, I had one of those antiques and I got sick of saying "Did I HEAR that?"

Toss yours out...It also takes too many hands...and all that fiddling and listening closely raises our BP and thus we don't get a "relaxed" reading.