http://www.filmakers.com/index.php?a...il&filmID=1314
this film was quite interesting when i saw it. they were of the opinion that much of the canadian sound comes from a mix of british and american english. this was because of the way canada was settled by brits and americans.
this site explains;
http://www.ic.arizona.edu/~lsp/Canadian/canhistory.html
and in part says:
The idea that a dialect is a hybrid often implies that it is not a distinct variety. Coupled with a collective sensitivity about their own identity, English Canadians will bristle at the suggestion that their speech is half-American, half-British, and not at all their own. This need not be the case: a dialect can be seen as a hybrid in terms of its history, but as a distinct form in terms of its current usage. That is, Canadians can claim to speak a distinct variety of English that has the English of both Americans and British as its predecessors.
We can tie the dualistic background of Canadian English directly to the dualistic background of the settlement of English Canada. Following the seizing of the French colony of Quebec in 1761, all of eastern North America was under the control of the British Empire. The thirteen American colonies had already been densely settled, and the dialects of the eastern seaboard had begun to emerge. Maritime Canada had also seen settlement, which is part of why Maritime English remains distinct today.
However, Upper Canada, the region that was to become Ontario, now Canada's most populous province, was at that time sparsely settled. Migration of Europeans to Ontario lagged behind that of the eastern colonies for several reasons, notably among them the harshness of the winter and its distance from ocean ports. Following the American Revolution, however, settlement of Ontario increased in pace, both with the continuing arrival of Europeans, but more significantly with the migration of Loyalists (or "Tories") who fled the United States.