▁much ▁of ▁the ▁American ▁South , ▁Mid land , ▁and ▁West . ▁ ▁The ▁di ph th ong ▁, ▁as ▁in ▁ow , ▁is ▁mon oph th ong ized ▁to ▁ ▁in ▁some ▁environments ▁( s ounding ▁instead ▁like ▁ah ), ▁including ▁before ▁nas al ▁con son ants ▁( e . g ., ▁dow nt own ▁ ▁and ▁found ▁), ▁liquid ▁con son ants ▁( e . g ., ▁f ow l , ▁hour ) ▁and ▁ob stru ents ▁( e . g ., ▁house ▁, ▁out , ▁cloud y ). ▁This ▁mon oph th ong ization ▁does ▁not ▁occur , ▁however , ▁in ▁word - final ▁positions ▁( e . g ., ▁how , ▁now ), ▁where ▁the ▁di ph th ong ▁remains ▁. ▁This ▁is ▁one ▁of ▁the ▁few ▁features , ▁if ▁not ▁the ▁only ▁one , ▁restricted ▁almost ▁exclus ively ▁to ▁western ▁Pennsylvania ▁in ▁North ▁America , ▁although ▁it ▁can ▁sometimes ▁be ▁found ▁in ▁other ▁acc ents ▁of ▁the ▁English - spe aking ▁world , ▁such ▁as ▁C ock ney ▁and ▁South ▁African ▁English . ▁This ▁sound ▁may ▁be ▁the ▁result ▁of ▁contact ▁from ▁S lav ic ▁languages ▁during ▁the ▁early ▁tw enti eth ▁century . ▁Mon op th ong ization ▁also ▁occurs ▁for ▁the ▁sound ▁, ▁as ▁in ▁eye , ▁before ▁liquid ▁con son ants , ▁ ▁so ▁that ▁tile ▁is ▁pron ounced ▁; ▁p ile ▁is ▁pron ounced ▁; ▁and ▁iron ▁is ▁pron ounced ▁. ▁Due ▁to ▁this ▁phenomen on , ▁t ire ▁may ▁merge ▁with ▁the ▁sound