when in Ireland or in Scotland (or speaking to people from such locales) I found myself numerous times trying to speak in proper accent to be better understood. When speaking to non-native english speaker, especially over the phone I embarassingly note from time to time that i speak slowly, articulating every vowel - like Iiii aaam retaaaaaarded, seend meeee aaaan aaaaambulance - very embarassing . required conscious effort to start speaking normally...
AX