In United States slang, the Bronx cheer is a noise made to signify derision, made by sticking out the tongue between the lips and blowing to make a sound reminiscent of flatulence. It is also sometimes known as The Raspberry. It could be very roughly transliterated as brrrrpppp!.
One of the most famous uses of the Bronx Cheer is in the 1942 recording Der Fuehrer's Face by musical comedian Spike Jones, which shows disdain for Adolf Hitler with the repeated refrain "We'll Heil! (Bronx cheer sound)! Heil! (Bronx cheer sound)! Right in Der Feuhrer's Face!"