Oxford Advanced Learner's Dictionary of Current English has the following phonetic symbols:
meddle
/ ˈmedl; ˋmɛdl/
medal
/ ˈmedl; ˋmɛdl/
mettle
/ ˈmetl; ˋmɛtl/
metal
/ ˈmetl; ˋmɛtl/
Oxford gives British English usages; in BrE, meddle and medal are pronounced the same and mettle and metal are the same too.
I know that in AmE, t is usually pronounced as d.
Then how are metal and mettle pronounced?
Are they pronounced exactly the same as medal and meddle in AmE?
Adding to my confusion: please look at how they are pronounced in Merriam-Webster.
meddle
Pronunciation: 'me-dəl
medal
Pronunciation: 'me-dəl
mettle
Pronunciation: 'me-təl
metal
Pronunciation: 'me-təl