My friend who gave me the info above had his own idea of how it might work, and described it thus:
“Picard…”
<Captain calling someone, load the list of likely candidates>
“…to…”
<ignore that>
“…Commander…”
<Only a few commanders on the Enterprise that Picard’s likely to want to talk to, at this time.>
“…Ri…”
<That’ll be Riker. Re-route and play.>
“…ker”
I know why Riker seldom taps his badge!
Riker is actually a semi-latent tele-kinetic. His power is just barely usable, affecting only small objects near to him. In many cases, his mere INTENT to hit the combadge causes it to be triggered!
Oh, come on… who hasn’t thought that Riker must be SOME kind of mutant! 
Too bad he took off with that traveler guy.
just had the communicator problem solved:
as Picard pages Crusher, and as the com directs it to( after knowing the destination ) Crusher,
she (meanwhile the captain starts relaying his message), she hears a chipmunk Picard calling her, then all timing is good 
euhhh…ermmm…
hits the com:"Computer! site to site transport! ENERGIZE!
Q in the transport sound
:eek: Not that Crusher, you Klingon Taint.
There will be a point in which latency cannot be reduced, even when travelling beyond the speed of light is achieved. The show emphasizes that very well.
There is the dissemination of the communication and its response. That takes time.
There is also latency tolerance that is built-in to systems that is required to avoid overload. That little latency tolerance, I believe, makes the average human respond to stimuli in 0.12 seconds. A human responding faster than that is considered to have ‘anticipated’ the stimulus. Data, though unexplained, probably has such a system built in to sync just faster than human reflex. But the interval is still there.