This sound effect can be found on Hanna-Barbera Sound Effects Library, which was made by Sound Ideas. This version was used as Squidward plays with spoons on his knees as part of a Pioneer tradition, described in subtitles and closed captions as ( spoons rattling ). This may be the actual source of this classic sound. Links: https://soundeffects.fandom.com/wiki/Sound_Ideas,_TEETH,_CARTOON_-_SCOOBY%27S_TEETH_CHATTER,_LONG#Audio_Samples