Story highlights You may not recognize their faces, but some voice actors are working steadily

One of the most famous, Seth MacFarlane recently hosted "Saturday Night Live"

Actors say the Internet has helped to grow their fan base

Frank Welker's name may not immediately ring a bell to you, but you almost certainly know his voice. He's acted in nearly 700 films and television shows.

From Fred in "Scooby Doo" to Ray in "The Real Ghostbusters" to the most recent "Garfield" -- if it's an animated show, there's a very good chance you'll hear Welker's work (he also specializes in animals, like "Aladdin's" Abu).

He can currently be heard reprising his memorable role as the evil Megatron on "Transformers Prime," with his old friend, Peter Cullen, who plays one of the most noble characters ever created , Optimus Prime. Cullen was also a mainstay of 1980s animation, in roles such as Venger in "Dungeons & Dragons."

Welker and Cullen make their living as voice actors and it's not easy to forget, as the pair of them often break into voices like John Wayne, Peter Lorre and Jabberjaw, one of Welker's favorites.

However, more and more A-list actors are joining the voice-over club over the last 20 years.

It's even gotten to the point where Chris Rock, star of the "Madagascar" franchise, took the opportunity of presenting an animation Oscar to quip about how "easy" it is to do voice work.

Rock joked that all he had to do was say the lines, "And then they give me a million dollars." (No less than Danny DeVito took issue with that characterization.)

Voice actor Seth MacFarlane -- creator of "Family Guy," "American Dad" and "The Cleveland Show" -- is enough of an A-lister to host both "Saturday Night Live" and next year's Oscars.

So how has the world of voice acting changed since Welker and Cullen's early days (besides the fact that a show like "Mighty Man and Yukk," their first job together, probably wouldn't get made today)?

"The technology has changed a lot," Welker told CNN.

"You see the CGI animation is so pretty and you could do a lot more with it than our old flat animation which I still like, of course. Watching those shows absolutely blows me away on an HD screen. You see so much more detail. It gives the actor more opportunity to bend your voice and be more subtle."

Cullen said, "The respect level (for voice acting) is climbing and climbing faster than it ever did before in the last few years. The studios are recognizing they don't have to hire a big name actor. People don't know the difference in most cases. They're finding they can take a chance with talent and accomplish the same thing."

Welker also noted that the Internet has made a big difference, and made it easier for fans to follow particular voice actors.

"In the old days doing the show, we never got one piece of fan mail," he said. "We had no idea there was an audience out there. The only way to tell there was some interest was if we got picked up for another season -- oh, somebody liked us."

Crispin Freeman became a voice actor in 1997, just at the time when animation attracting A-listers was going strong. He's best known for his work dubbing Japanese anime like "Howl's Moving Castle" and most recently Cartoon Network's "Young Justice." Cartoon Network is owned CNN's parent company.

"Voice actors have always been quite popular in Japan, but American culture is now becoming more aware of the artistic contribution of voice actors because of the swell in popularity of video games and animated films," he said.

"Not only have both mediums been expanding their market penetration in America in recent years, but the maturity of the storytelling in each medium has grown as well," Freeman said.

"This attracts an older audience that is more curious about the performers behind their favorite animation or video game character. It seems that as we see a convergence of film, animation and video games, American audiences will become more and more aware of the importance of voice acting."

Patrick Seitz has a slightly different perspective. He got into voicing even more recently, in 2000, and is mostly involved with the world of video game voice work, as well as anime.

"I don't know if voice acting is more respected, per se, but I do think it's a higher profile pursuit than it was in decades past," he said.

"Games progressing to the point where they can be fully voiced has opened a whole new sphere of awareness and fandom, and ever since the animated feature films got the idea to fill their casts with celebrities (for better or for worse), they've never looked back."

But he certainly agrees with Cullen and Welker that online fandom for voice actors has been a game changer.

"It's amazing how completely some of the fans have sussed out our vocal fingerprint, so to speak. I've had folks identify me based on nothing more than a roar."