Two things to keep in mind:
1) In order to develop an "ear" for accents (much like for foreign languages in general) one needs to be exposed to them often;
2) Americans tend only to hear their own particular regional accent or TV-speak "California English".
My father has a heavy Boston accent makes him sound like a cross between a Kennedy and Katherine Hepburn (without the jumps). When he and my mother were first married, they lived briefly in the south (Georgia and W Virginia) as he studied Forestry in college and those were the areas he found work. Evidently he simply could not make himself understood by the locals; my mom's voice just has a touch of Down East Maine and never had a problem
My last partner (nine year relationship) had several good qualities, but understanding accents wasn't one of them. The rule for renting movies was No Subtitles, so I could only watch foreign films when he went away. He broke this rule when DVDs came out, but only for British films like
Trainspotting or Guy Richie movies, where they suddenly became mandatory.
FWIW, I've never had an issue comprehending accents, but I grew up watching
Monty Python and
No, Honestly :biggrin1: