I was watching tv the other day - a gathering of teens/college age kids in Houston and there was definitely a common sound to their speech but it wasn't southern! We are losing our southern accent I think
we say ANT for aunt also, but my niece will tease sometimes and call me ONTee. and we say puhkahns too.
People from the northeast (like Boston) say “ont” as well. My college roommate from there said that.