Talking toys have been around since Edison made a doll that recited nursery rhymes by means of a small hand-cranked phonograph. Now there are dolls that reply emotively to a child, by name.

Ken Forsse, who died at 77 on March 19 at his home in Laguna Woods, Calif., advanced the field in the 1980s by inventing a plush bear that made appropriate facial expressions as it told stories or sang. His creation, Teddy Ruxpin, was almost impossible for harried parents to find when it burst on the scene in 1985, and it remained wildly popular through the next year. In 2003 the Toy Industry Association named it one of the most memorable and creative toys of the 20th century.

His wife of 26 years, the former Jan Hornbeck, said he died of congestive heart failure.

For Mr. Forsse (pronounced FOR-see), Teddy Ruxpin was not in the same class as other hit toys of the 1980s, like the Cabbage Patch Dolls, the Care Bears and the Pound Puppies. To him, it was more than just another toy. It was a mythical character with a fully developed fantasy world, one that Mr. Forsse had been dreaming up for 30 years.

For 12 years he had worked for Disney, helping to develop “It’s a Small World,” “Jungle Cruise” and other attractions for Disney theme parks. He went on to work with Sid and Marty Krofft, the producers of “H. R. Pufnstuf” and other children’s television shows. But it was not until he started his own company, Alchemy II, in the early 1980s that Teddy came to fruition. (The name seems simply to have popped into Mr. Forsse’s head.)