One of the reasons the comic book is my favorite artistic medium is how much more they offer the audience a chance to fill in the sequential blanks. It's common knowledge in comic theory that the action occurs in the gutters between the panels, just like music theory posits the importance of the space between the notes. Depending on how engaged you are in the reading, you can imagine massive theatrical productions between the lines, impressive animated motions with powerful voices. The voices and movements not provided for you like in TV or film; yet at the same time, you are given more to " work with " than with prose.
This is not to posit comics as the superior medium, but to emphasize the importance of voice in comics, and why it's such a useful tool for creators and audiences alike. When I read a favorite comic series, be it a gag strip like Penny Arcade, an enduring superhero comic like Iron Man, or a darkly comic satire like Preacher, I like to have clear ideas of what each character sounds like as I read. I draw upon my memory of various actor voices from animation and live-action, and try to find an appropriate voice. I also do this for my own work on Ruby's World; for example, every time I write Ruby's dialogue, I imagine her sounding like Alyson Hannigan playing Willow in the early seasons of Buffy.* The characters are different, but there's a similar vein there; Hannigan specialized in playing intelligent but socially awkward and unusual girls with strong senses of obedience to the rules. Prior to her transformation, Ruby was a pathological overachiever much like Willow, and that carries over even in her outlaw life in current strips, Hannigan's nervous, scattered energy adapted to my own work.
Of course, this isn't just a tool I use for my own stuff; it also enhances my fandoms. In the case of superhero franchise comics that have spawned countless extra-media adaptations, this task is easier; who in their right mind would NOT hearRon Perlman when they think of Hellboy's voice? Even with characters who have had multiple voices, there are still clear favorites; to me, tbere is no Wolverine but Steve Blum, and all others pale before the gravely adonis he represents. But then, there are plenty of characters who haven't appeared in other media, so how are they interpreted? What do we go on for those existing only in comics?
As much as it sometimes seems, comics do not exist in a vaccuum; they are stories connected to the rest of pop culture. For example, a character like the comic villain Herr Starr from Preacher draws upon several tropes; he's a bombastic dictator, a stereotypically evil German, a sexual deviant of increasing perversions, and a fool who's often humiliated by his own designs. So the connection I make; Kelsey Grammer, doing the voice of the Simpsons' erudite psychopath Sideshow Bob. The connection enhances the reading; Starr's lines sound much more horrific/pathetic when expressed through Grammer's voice, even if Sideshow Bob never endured nearly the same level of torment that Starr received ( getting hit in the face by a rake repeatedly still doesn't compare to being anally raped by an accidentally male prostitute in your first appearance ).
I rarely hear mention of this theory, since it requires so much internal influence; Wolverine may be Blum to me, but he could be
Cal Dodd, Scott McNeill, Hugh Jackman, or That Guy Who Made Him Sound Australian to any other reader. But they all contribute to the larger understanding of who Wolverine is, and how he goes from being lines on a paper in the form of a hairy little thug in a canary yellow clown suit to a meaningful icon. Every aspect contributes to the larger experience, even if it's just subjective interpretation of how the characters might sound.
Except for Australian Wolverine. That's just wrong.
( * Caveat; I write Ruby sounding like early Willow. Before all the Wicca crap; before the character went from a responsible, scientific mind to a magic junkie who blasts everything away when she's not pretending to be exclusively lesbian.