Joseph-
“How was your B-I-L better able to understand?“
I have no idea, but I gratefully accepted his help.
Some people are just better at languages and/or deciphering accents.
I work with people who have Russian, Chinese, Israeli, Indian, Pakastini, Philipino, English, Irish, South African and many more accents, but this particular CSR was the champ as far as unintelligibility goes.