It seems that I was incorrect in a posting earlier this week (and in my
bard guide on EQVault). Hymn of Restoration now appears to cause a
regenerative effect, rather that a heal per pulse effect. So if you
start the Hymn, then turn the song off, you still heal at the increased
rate for the duration of the song effect (while the icon remains on the
screen). This is not how it behaved early in beta, but it's good news
for us bards.

The way it seems to work, and it's understandable how I was confused
when you see how it works, is that when the first pulse kicks in, your
health goes up by the appropriate amount (which is something like 3 plus
one per six levels plus 2 if you're holding an instrument and plus 2 if
you're seated). There are then approximately two more "ticks" where
your health will go up again. These "ticks" are synchronized with the
song's pulses, and will occur even if you stop singing.

The amount that the "tick" heals is probably determined by
instrument/sitting etc. at the time of the tick, rather than the time of
the original pulse, so standing up after the first tick will probably
reduce the amount you are healed on the second and third tick. I
haven't verified this though.

Jyzan