I have no vested interest either way but I would find that to be unlikely. Do you have links with proof either way.
I'm an ex-language student. When a story comes in front of me about people 'suddenly acquiring foreign accents,' I study it with special care. No, I have no links for you, but I've been following reports of the phenomenon carefully for some time now.
However unlikely you find it to be, I'm pretty sure it is exactly as I describe. Have you ever studied phonetics and the physiology of speech? I have, and I can report to you that the explanation I've offered is not only the one offered by experts, but makes perfect sense to me. Nerve damage affects the mouth and tongue, causing speech which coincidentally sounds like a 'foreign accent.'
That is not he case in some of the examples of what I mentioned.
I believe you're mistaken. No one spontaneously begins to speak a language which they've never heard before. Old wives' tale. Or false reports. I'm pretty sure.
I agree that it is certainly amazing, but why in the world is sudden musical knowledge believable and language not.
Because (a specific unknown) language is data, but musical ability isn't. Musical knowledge doesn't become available to the trauma victim. The person doesn't suddenly sit down at a piano and play a particular Chopin sonata. Instead, he just gains the ability to learn the piece very quickly and fluently.
I think all the trauma I have suffered took abilities away instead of granting them. I can't carry a tune in a bucket.
If you're really desperate, you could try diving into the shallow end of the pool, but I wouldn't recommend it. Sudden talent only comes to the trauma victim once in a million headbutts.