I can't tell the difference between [o] and [Q].

Travis: As I've mentioned on another thread, I think that at least in my speech, free vowels *do* tend to be longer, in any given situation, than checked vowels. I do have a little bit of vowel length allophony based on the following consonant, but I really think that the length differences between checked and free vowels are equally if not more significant.

bet ["bEt]
bed ["bE:\d] (I use the half length mark here because I think, at least for me, that it would be excessive to mark it as fully long. It doesn't sound as long as Estuary "bared", for example, and I don't think it sounds as long as the vowel I use in "cod".)

cot ["k_hQ:\t] (The vowel is a bit shorter here, but not as short as the vowel I use in "bet".)
cod ["k_hQ:d]

I think my [Q:] sounds different from RP [Q] because it's slightly opener and less rounded, but also because it's longer.

So I think that in my speech at least, my convention does generally coincide with phonetic reality.

I think that's about the same as my situation, though there are of course effects of stress as well. I think my low vowels may be longer before voiceless fricative than voiceless stops (like in the precursors to the trap-bath and lot-cloth splits). Also, /a/ seems to be neither tense nor lax and varies more in length than either.

bat [ba?]
bad [ba:d]
bath [ba:T]

cot [kQ:\?]
cod [kQ:d]
cough [kQ:f]

<<That may be true, but I would expect Spanish speakers to confuse [o] with [u] and [Q] with [O], rather than both [o] and [Q] with [O]. What was your experience in learning English?>>

I cannot remember much about my own pronunciation and/or perception of English in my early days of learning it. I have taught English to native speakers of Spanish though, and in my experience they often produce [ou] for /@U/, [O:] or even [o:] for /O:/ and [O] or [o] for /Q/ (except those who are more exposed to American TV and movies, who may have [A]). I do remember that learning phonology more methodically was an eye-opener (or an "ear-opener" perhaps). The revelations that came with it were astonishing!

in Toronto English, the merged vowel /A/ is more used than the merged vowel /Q/ (the vowel in dawn/Don).
/Q/ is preferred by women, /A/ by men (compare to Californian English).
Mississauga and Chicago share the same stressed vowel which is /A/ (and not /Q/) but then again, many people use two vowels...

I had [O] and [o] mixed up in the topic, for that who asked.

>> in Toronto English, the merged vowel /A/ is more used than the merged vowel /Q/ (the vowel in dawn/Don).
/Q/ is preferred by women, /A/ by men (compare to Californian English).
Mississauga and Chicago share the same stressed vowel which is /A/ (and not /Q/) but then again, many people use two vowels... <<

I think it completely depends on the speaker, rather than the region. From what I've read, the Canadian and California vowel shifts don't really vary very much by region.

''I think it completely depends on the speaker, rather than the region. From what I've read, the Canadian and California vowel shifts don't really vary very much by region.''

that's true.

I also find it hard to believe that there's a significant difference in accent between Toronto and Mississauga, since so many people live in one and work in the other, or move between the two.

''I also find it hard to believe that there's a significant difference in accent between Toronto and Mississauga, since so many people live in one and work in the other, or move between the two.''

A perfect example of Toronto English:
http://youtube.com/watch?v=GPbKJVyx0rs