I recently read Alice Munro‘s famous short story collection Dear Life, my interest piqued after the Canadian writer’s recent Nobel Prize win. I enjoy watching interviews with authors I’m reading, so I looked up several with Munro on YouTube. I was also, I admit, curious about the accent of someone who grew up in rural Ontario before World War II:
Like several older Canadian I’ve heard, Munro’s accent strikes me as, in some respects, less marked (from an American perspective) than that of many younger Canadians; her Canadian Vowel shift seems rather intermittent. She exhibits, however, a feature that has always struck me as being a slight if inconsistent divider between Canadian and American English: she sometimes pronounces the /t/ in words like “later” and “writer” with an aspirated plosive where many Americans would use a tapped or voiced vowel (i.e. “writer” and “rider” would sound roughly the same).*
My impression is that Canadians these days more likely to use the same consonant in “rider” as the one they use in “writer.” But I can’t say how much of a change this is; it seems to me that there used to be more Americans who used un-tapped /t/ in these words as well, and it’s likely that, conversely, tapped /t/ has been a feature in Canadian English for a long time.
So all I can really say is that, impressions aside, Munro’s idiolect (rural southwest Ontario possibly influenced by decades living in Vancouver) often features an aspirated /t/ in this environment where, say, mine does not. There are clearly a large number of allophones for intervocalic /t/ in various dialects of English; why some accents and possibly even some people use certain variants where others do not strikes me as one of the more intriguing mysteries of English phonology.
*In some parts of the Northern US, however, there is a trend away from tapped /t/ and toward the glottal stop more typical of some British accents. Hence while back in a Connecticut recently I overheard someone in a restaurant pronounce the phrase “but it wasn’t” bʌʔ ɪʔ wʌznʔ.