Baby translator
Wikisimpsons - The Simpsons Wiki
The Baby Translator was an invention by Herb Powell in the episode Brother, can you spare two dimes?
History
Herb tried to make an invention that would make him rich again so he makes a translator to babies. Since Herb had no money, Herb asked Homer if he could have $2,000. Since he gave him the money Homer got $2,000 and a Spine Melter. That's the history.
NOTE: The project was not ever seen again.