David Schwimmer's mother's laugh could be heard over many Friends episodes.
Schwimmer - who played Ross Geller in the NBC sitcom - has revealed that his parents, Arthur and Arlene, would often be sat in the studio audience during filming and his mother's distinct laugh would often bellow over the rest of the attendees.
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Speaking on UK TV show This Morning, Schwimmer said: "My parents lived in LA where we shot the show. Occasionally they'd come and see the show. My mom has a very distinctive laugh. It wasn't until later that it came to my attention. My sister said, 'Did you hear mom laughing at the background?'"
Schwimmer made the revelation after host Phillip Schofield played him a clip from the show, where the presenter's own laugh could be heard from the studio audience.
The comic star admitted that the lack of a studio audience posed a challenge during the making of his new comedy series Intelligence because there were no laughs to give the performers an indication of what was working in the script.
He explained: "This show is tricky because its single camera and we had no live audience, so we had to really trust what we are doing is funny because you don't get that immediate feedback."
Schwimmer plays the role of American agent Jerry, who moves to the UK to join GCHQ. He forms a friendship with Joseph, played by Nick Mohammed who also created the show - despite his arrogance.
Schwimmer explained: "He assumes that he, being American, does everything better and owns every room he walks into. He's the kind of guy who, whatever, he lacks in actual experience, he makes up for in confidence. He's this brash narcissist who's very patriotic, even though he's never been out of America."
The Madagascar star revealed that he enjoyed the blend of physical and situational comedy on the show.
David said: "We both love physical comedy and Nick is supremely good at it. It's the kind of comedy I dream of making.
"Not only is he a truly gifted writer, so the lines are delicious, he is also a great performer, so you have a blend of situation comedy and physical comedy."