Reddit is full of 'Americans' whoopin' & a-hollerin'
YEE-HAA
(pissflaps., Fri 30 Nov 2012, 9:19, Reply)

ahem
It is pronounced "Ye-Haw"
( flirting with badgers What? It sounded good at the time., Fri 30 Nov 2012, 19:32, Reply)