I've been thinking a lot (too much) lately about /t/s in English. I never really thought about them before, so I guess this I was overdue. Really, though, I never knew how much there was to know! I'd heard about flapping, but didn't know what all the, umm, fuss... was about. What fascinates me most though is how most Americans are completely unaware of flapping, that is, that the 't' sound before unstressed vowels really doesn't sound much like a /t/ at all, at least when uttered (or uddered) by Americans. And not just 't's, but 'd's as well. That's why 'uttered' and 'uddered' sound the same. Here are three anecdotes about this.
1) In an acting class my freshman year of high school, the teacher admonished us for "not pronouncing our 't's - there's a 't' in 'battle' - I need to hear it." So we had to say 'ba-tel' to get her off our collective case. Nevermind that that's not how you say that word in American English.
2) At a conference recently a handout for a talk included some transcribed speech, in which the word 'later' was followed by "(lader)" seemingly chastising the informant for flapping her 't's.
3) The recorded interface in my voicemail system, which generally sounds chatty and colloquial, says "This message has been De Lee, Ted," which always makes me want to say, 'My name isn't Ted.'
Frankly, I don't really care that people don't know about flapping 't's. Why should they? But it's interesting that this particular sound gets attention where others don't; I can't imagine an acting teacher telling actors to devoice the 's' in 'rose,' for instance.