I don't usually hear it, unless I try to. If I get my heart rate up, I will sometimes hear my heart pumping faster (maybe raised blood pressure could also make it louder?).
I can feel it in my chest, and it's sometimes positional.
I've had issues -- my wife said that it's a blessing because she knows that it saved my life. I once got an old Mickey Mouse watch - 5 clicks per second - she was afraid that I was having a heart attack.
I couldn't play hide and seek with my daughter because she heard me clicking through a door.
I went to a press conference. A jerk in a row in front of me, and a few seats over, kept looking behind him. I opened my mouth and pointed it at him, assuming that I could MAYBE project the clicks toward him. He kept glaring behind him. Finally, he shouted out 'who's wearing the cheap watch?" I said it was my heart valve.
After the conference, I watched him slinking away.
--
Yes, you can use the clicks to get your heart rate.
You can probably also use it as a simple hearing test for those around you.