The women, Amy Walker, pretty much does exactly what the title would suggest: 21 accents in 2 minutes 30 seconds. No surprise there. Skip forward (or just wait, because the rest of her accents are actually pretty good) to 1:45 and you’ll get the Seattle accent.
Now, up until this time, I was never aware that Seattle had it’s own distinct accent. As it turns out, Seattle may. I found a 2005 article by the Seattle PI (that would be “Post-Intelligencer” for all you non-natives), Contrary to belief, local linguists say Northwest has distinctive dialect, that reports that “Jennifer Ingle, a 27-year-old Ballard native and student of language at the University of Washington” did a study on the Northwests’ distinct accent:
Say “caught” and “cot” out loud. If you’re a true Northwest speaker, the words will sound identical. Linguists call this the “low-back merger” because we’ve merged these two vowel sounds. On much of the East Coast, these same words will sound different. “Creaking is a way of making those distinctions that are being lost,” Wassink said. Just as Bostonians tend to compensate in their speech for removing the “r” from many words, she said, we might speak creaky to compensate for refusing to use both vowels.