THE Philadelphia regional accent remains arguably the most distinctive, and least imitable, accent in North America. Let’s not argue about this. Ask anyone to do a Lawn Guyland accent or a charming Southern drawl and that person will approximate it. Same goes for a Texas twang or New Orleans yat, a Valley Girl totally omigod. Philly-South Jersey patois is a bit harder: No vowel escapes diphthongery, no hard consonant is safe from a mid-palate dent. Extra syllables pile up so as to avoid inconvenient tongue contact or mouth closure. If you forget to listen closely, the Philadelphia, or Filelfia, accent may sound like mumbled Mandarin without the tonal shifts.

Some dialects can be transcribed onto the page, but the Philadelphia accent really has to be heard to be believed. And when an accent goes silent, so do its speakers. A recent study out of the University of Pennsylvania reported that, like many regional phenomena, the Philly sound is conforming more and more with the mainstream of Northern accents. And that’s a shame. The beauty of the Philly accent, and I should point out it’s mostly to whites that these sweeping statements apply, is its mashing-up of the Northern and Southern. Nowhere but in the Delaware Valley can you hear those rounded vowels — soda is sewda, house is hay-ouse — a clear influence from Baltimore and points south.

An upstate New Yorker now, I miss my native tongue, especially this time of year, when, dutiful moviegoer that I am, I cram in as many movies nominated for the Academy Awards as I can. What’s becoming more and more clear is that, to the extent it ever appeared, the Filelfia accent, reflecting the general trend, has all but disappeared from the screen.