Thee, thy, thou (along with tha and the more rarely used thine) re widely used around the area I live, and its used as stereotypical characters for this area by comedians.
Yorkshire.
http://en.wikipedia.org/wiki/Yorkshireisms
http://www.laufman.org/SongsTunes/IlkleyMoor.htm
The parent site to this link has various folk from around the Yorkshire region reading various dialect poems, the link following probably represent the local accent best.
http://www.yorkshire-dialect.org/authors/fred_hirst_b_c.htm#bonfire_neet
Something you also might need to understand, is that local accents around here can be recognisably differant, even within a distance of rather less than ten miles, for instance, Leeds, just up the road by 8 miles, is very differant to here, Castleford, and if you drive just another 5 miles or so to Featherstone, you’ll find they speak differantly there.
The, thou, thy etc are most commonly associated with South Yorkshire, especially around the Barnsley area.
http://www.bbc.co.uk/northyorkshire/voices2005/glossary/glossary.shtml#
Some words are recognised as being spoken in a way that would be called, medieval, and retain vowel sounds that have been lost eleswhere centuries ago, we might pronounce *speak, meat or eat * not with the double E sound, but extend and pronounce the a sound as well so your speak - speek, becomes our spee-ack meat - meet to us mee-at.
Other vowel extensions and changes, the classic would be for boots, we would say boo-its, or ‘get thee boo-it on, we’re off laikin’ meaning ‘Put on your boots, we are going out to play’, which should be taken to mean ’ Get yourself dressed up, we are going out and painting the town red’
Some of these local dialects are very old indeed, quite why we still use them and haven’t moved on I’m not sure, we seem to be a target for charicature, I think probably any region with strong dialect gets this treatment from the so-called, ‘correct’ English.
To be honest, you if you play some of those sound files in that second link, you will most probably notice a lot of things I wouldn’t, simply because its the way I talk, and its just normal, the accents dont seem all that strong to me (one or two do sound like they are putting it on a bit thick to me, and making more of their speech than is natural for them)
I would be interested in what you make of the way we speak from those soundfiles, you will probably notice far more than I would, I guess you don’t realise you have an accent at all until you speak to someone from outside your area, but then, it is everyone else what speaks odd!