During a fan Q&A at London Comic Con in 2012 (via Youtube), Sean Schmell revealed that he once fainted in the actor's booth. The voice actor behind Goku explained that his passing out during "Dragon Ball GT" had less to do with the intensity of the screaming, and more to do with his health and acting technique at the time.
"It was during the Super Saiyan 4 transformation, and I was really tired ... and hadn't been sleeping well. I miscalculated the amount of air you'd need for a Kamehameha, I think or maybe it was a power-up, and I made the voice lower," Schmell explained. "So as you get lower, when you're acting, the aperture of your vocal cords gets wider, and I just totally miscalculated."
Because his wider vocal posture allowed more air to escape his lungs than he expected, Schmell ended up passing out right there, which Schmell called "kind of fun... it was like falling asleep really quickly." Luckily, the booth was padded so Schmell wasn't injured, and after a few moments, he was able to get up and continue working.
