Rosen's family moved to Long Beach when he was age 7 and he graduated from Long Beach State by 1963. Shortly after he got a job at KCET as a production assistant. In 1965, channel 2 was looking for a kid's show, so Rosen pitched _Dusty's Treehouse (1968-1980)_ to CBS and ended up doing the show for 10 years. In the early '80s, Rosen was involved in several cable startups at the dawn of a new generation. He was also the casting director for the Teenage Mutant Ninja Turtles (1987) and the voice director for several hit cartoon shows such as Mask (1985), My Little Pony: The Movie (1986), Captain N: The Game Master (1989), Defenders of the Earth (1986) and _Fraggle Rock (TV Series 1987-1988)_.Entering the 90s he was the voice director for computer game Gabriel Knight: Sins of the Fathers (1993) and also did the voice for Yuri Markarov in Quest for Glory IV: Shadows of Darkness (1994).Over his career, Rosen won several Emmys; ten L.A. Emmys and the George Foster Peabody Award.