I haven't done the experiment yet... but I was thinking more about this and it enlightened me with one very interesting point....
speaking another language fluently or by understanding what we are speaking differs from saying just few words for fun or for travel purpose or similar purpose (saying words without giving much thought into what we are saying) is very different...
I have come across few, who were not native tamil speakers but have learnt and spoken Tamil... There were no accents!!!!!! (I had to recollect and analyse about that.. as, at those times, I wasn't speaking any other language)....
but, there are different tamil accents, which are mainly regional differences...
there is a different scenerio.. Hindi spoken by Tamilians is easily identifiable by its accent... but, When I learnt hindi and started speaking everyone around me told that I didn't get that accent.. Later (When I had enough understanding/knowledge on hindi to be able to differentiate different accents) I found out that, people who learnt hindi in tamil nadu or in tamil groups, had that accent... but I learnt hindi from core-hindi-speaking area, and from the locals.. i didnot have any prior knowledge about hindi.. so, I learnt the real-accent..
there is another scenerio...
one of my turkish colleague's wife didn't know
any English at all when she came here. she learnt English in Brittain.. amazingly she had that typical middle eastian accent!!!
I think main difference in Tamil is that language (the micro unit in Tamil) is defined by the time you take to say it.. so, you cannot change the way it is spoken... next things, is there are very few pronounciations that you will get wrong (such as the deep "l" thing).. otherwise, all tamil sounds are from inner-most-mouth to tip of lips... whereas in hindi you have to use lungs to say "ha" sounds (G+ha, D+ha, T+ha, ch+ha, J+ha, b+ha, p+ha.... etc)....
but, if a native english speaker speaks tamil without understanding it, he/she will speak using your tip of the tongue mainly...