Thanks for your endeavor. But in Oxford Advanced Learner's, some pronunciations by the female actor are cot-caught merged, while others by the male actor are not so. I think they recorded only some of them following cot-caught merger. I couldn't find Cambridge Advanced Learner's online dictionary. I guess cot-caught merger's percentage will overturn non merger in the near future.
Anyway, here on this website, I learned from some teachers that America doesn't have any standard language, respecting each state's accent as it is, so whether cot-caught merger is higher in percentage or not, I feel we should respect both ways equally.
Remember that the cot/caught merger is a phonological merger (rather than a phonetic merger).
Both Vancouver and Seattle are cot/caught merged,
but,
most people in Vancouver pronounce
dollar, song, politics, lot, Don/Dawn, naughty/knotty with the rounded vowel [ɒ] (RP British English
John/song vowel),
while in Seattle most people have the unrounded vowel [ɑ] in these words.
Chicago is cot-caught
unmerged, but
cot is [kät] (low central unrounded) or [kat] (low front unrounded), while
caught is [kɑt] (low back unrounded vowel). So, many people in Chicago/Cleveland/Detroit/Buffalo pronounce words like
caught, long, wall with [ɑ], exactly the same way most people in the low back merged areas (for example St. John's NF, Plattsburgh NY,Burlington VT, Denver CO, Phoenix AZ or San Diego CA) pronounce these words.
Lana del Rey is a perfect example of a cot/caught merged person from the low back merged part of the New York state (NE part of this state, next to Vermont which is completely cot/caught merged to [ɑ]).
Listen to her song Video games...;-)
Many native New Yorkers, like Lady Gaga and Brooke Shilelds are cot/caught merged, but they've been accent coached in order to sound as if they were from California, it's not the native accent of the NYC area (although as I said before, the merger can be found in parts of the state of NY).