In Mark Hancock's latest homophone post, he shows how these MIGHT sound the same for some people (but not all):
However, a lot of people use the long ɑː for 'aunt' (but not 'ant') 'pasta' and 'passed'.
If you use the long ɑː for 'aunt', remember that it's a homophone of 'aren't'.Learners tend to mispronounce 'aren't' as 2 syllables [ar-runt*].
Members: Review homophones related to contractions (Page 3/10 on the Worksheet)
Notice also:
'passed a' = 'pasta' (Review Past Tense 'ed' pronunciation)
'My aunt's passed' = My aunt HAS passed
'My aunt's pasta' = Possessive 's'
Many people (myself included) pronuounce these the same.