Laugh track
（重定向自Laughtrack）
A laugh track (or laughter track) is a separate soundtrack for a recorded comedy show containing the sound of audience laughter. In some productions, the laughter is a live audience response instead; in the U.S., where it was most used, the term usually implies artificial laughter (canned laughter or fake laughter) made to be inserted into the show. This was invented by American sound engineer Charles "Charley" Douglass.