I've been told by a Welsh woman that that it is pronounced "shan." I'm just passing on info.
Before then, the only pronunciation that I had heard was
Sian Philips, the British actress (
Livia, in "I,
Claudius"). She pronounces it "shawn." But when a Welshwoman said it was "shan" I began to think that Ms. Philips' pronunciation was more English than Welsh. Is this making sense?
Like I said, I'm not an expert in Welsh pronunciation. Irish, yes. But not so much Welsh.