Reading the ELT Gazette last week, I came across an article about a case of foreign accent syndrome.
It was about a woman in the north-east of England who suffered a change of accent after a stroke. The woman's original Geordie (NE England) accent was replaced by a Jamaican one literally overnight.
Of course, this seems quite comical at first, but the woman actually finds it quite unnerving. This is because our accent is so much part of who we are, (our personality, our being) that it must be disturbing to lose it. And not only is her own state of being unsettled, but the people around her (neighbours, family, friends) treat her differently now because of the way she talks.
All this is food for thought surely for language teachers. I have always thought it difficult (if not impossible for some) to adopt the accent of a foreign language, and whenever asked by students about this, tend to tell them that it doesn't matter if they speak with their own accent so long as their pronunciation is clear enough for them to be understood.