"Hepp!" "Pling Pling~" like 'em both... I usually say "Coming around!" if my bear bell on the frame hasn't alerted them. One of the guys on the week-long tour I was on crashed when one of the joggers he called "on your left" to moved left (and the other moved right)- it's just not anything like universal.
If I'm in the mood, I'll break into song... I have been thanked profusely more often than I can say.
I, too, though, basically yield to peds on "multi-use" paths, which for me are on the last stretch of my trip so I'm ready to slow down a lot. Except for the 200 yards coming up to & from the college, I stay off the sidewalks (and I stay off that one if there's conflict on it - I can see it all before I commit) generally. The roads are much safer for all concerned.