This sound is from Bullshit Soundboard

"Bullshit" is a slang term and a profanity which means "nonsense" The term is used to distinguish from a deliberate, manipulative lie intended to subvert the truth.
See also: On Bullshit, Bullshit Jobs, Bullshit job, Bullshit (disambiguation), Penn & Teller: Bullshit!, and Party and Bullshit.