If you’ve seen recent episodes of "The Simpsons" in Spanish, chances are you've heard Eduardo Ramírez. He's the voice behind Nelson, Otto the Bus Driver, Bumblebee Man, and also Lenny.

Ramírez is a theater actor by training. A few years ago, a fellow actor suggested he learn dubbing — being a voiceover artist for Spanish-language soundtracks — to earn extra cash. Ramírez quickly learned that performing voices for TV audiences was a different craft than stage acting.

"They see a face and hear a voice,” Ramírez explained, "and the trick in dubbing is that they match, you know? That people aren't thinking, 'wait a minute. That voice doesn’t belong to that face.' That’s the tricky part."

Dubbing is a sub-category of work and training in Mexico. And Ramírez has been pretty successful - so far.

"You know, in theater, there are like 100 people who come to see you, but, for example The Simpsons, all of Latin America has this dubbing that we made here in Mexico," he said. That means millions of TV viewers across Latin America have heard Ramírez. So the money must be pretty good, right?

"No," said Ramírez, laughing. "Well, for example, in this agency where we work on The Simpsons, for what I did yesterday, like 10 minutes of work, it was like $20 - $25 dollars."

In Mexico, $20-a-day is still roughly four times the minimum wage. Plus, it only takes Ramírez about 10 minutes to record his character’s lines. So it seems like a decent living, until you consider the wide diffusion of the actor’s work.

"The thing is, this work goes to all of Latin America and maybe some parts of the USA, and so that’s where it becomes underpaid," Ramírez said.

Ramírez is part of a growing group of trained actors who feel that their work is undervalued, especially as the dubbing industry gets more competitive and as companies outsource the work to other Latin American countries. The actors claim that fans are complaining about having longtime voices suddenly replaced.

The fight between actors and dubbing companies first flared in 2005. That’s when Humberto Vélez — for 15 years the voice of Homer Simpson, or Homero, in Spanish — led the show’s core crew of Spanish dubbers in Mexico on strike for better pay. The actors lost and were replaced.

Mario Castañeda, the creative director at one of Mexico’s biggest dubbing studios, explained, "You can always say to the producers or to the dubbing company, 'Hey, I want to earn this money,' but then you have to realize something: you are not Homer Simpson, you are the voice."

Castañeda knows. He is one of Mexico’s most recognizable voices, having dubbed Bruce Willis and Jim Carrey films, along with TV shows like 'The Wonder Years' and 'Dragon Ball Z.' He thinks the dubbing industry increasingly sees voice actors as replaceable — especially with the rise of lower-cost studios in other parts of Latin America. Add to that, he said, the fact that non-Mexican actors are now mastering the coveted, generic Mexican accent.

"A lot of people are trying to get a better price, and some clients have switched to Argentina, to Venezuela, to Colombia, and to Chile," Castañeda said.

He estimates that Mexico’s dubbing industry has lost about one third of its business to competitors and that Mexican actors haven’t seen pay increases in more than 10 years. In the meantime, he argues, audiences have forgotten about the value once placed on having that subtly distinct voice.

"It’s like Mickey Mouse. I don’t know who Mickey Mouse is in the United States. Here in Latin America, it’s Arturo Mercado Junior, and he has been Mickey Mouse for more than a decade. But whenever they want to change him, they just have to look for someone who can say, 'Haha, hello, come on Pluto!' and if they can find a guy that can do that, that’s the voice of Mickey Mouse," Castañeda said.

And the way things are going, Mexico’s historic hold on the voices of popular TV shows, from Mickey Mouse to Los Simpsons, may soon become a thing of the past.