How can a healer heal someone they can't see? Perhaps the moaning of their dying comrade is enough to guide their prayers. Or the dying hears the inspiring words of the warlord through a haze of pain.
I know you are trying to be ironic, but your second example is correct. Some more examples (based on each healer class):
Cleric: "Pelor do not forsake us! Heal my comrade so he can serve you!". A wash of holy light flows over you, easing your pain and returning your strenght. Some pseudo-Latin chorus and some big major-third chords in an pipe organ sound from seemingly nowhere.
Warlord: You hear the words of your friend through the mists of unconsciousness...
"Seiya! You can't die dammit! We need to rescue Zaori! C'mon!"... You blink your eyes hard, once or twice, and push back on one knee, gripping your sword...
Bard: The Eladrin in makeup downpicks a power chord in his lute and screams in a Heavy-Metal falseto:
"Majeeeesstiiiic Woooord!!!"... The magical energy flows out of the sound waves, momentarily stunning an opponent and allowing you to move a couple steps into a better position. With this guy in your team, you feel like you could rock and roll all night!
Shaman: The guy in the loincloth raises his rattle:
"By the power of the Jungle, the Ghost-that-Walks grants you the strenght of ten tigers!" The ghostly panther by his side seems to jump into you and then you suddenly feel strong, healthy and with an unexplainable craving for very rare steaks
Did I miss anyone?