All the confusion and arguing that comes from misunderstanding mispronunciations really boils down to regional differences and trends. Sometimes coupon it's supper, sometimes it's dinner; sometimes coupon is pronounced "que-pon", other times it's pronounced "koo-pon". The more you travel, the more you realize how vastly different folks pronounce and define various elements of our national language — it's even more apparent here in the melting pot that is New York where your apartment neighbor could be cracking open a can of pop, while you pop open a can of soda.
North Carolina State University Ph.D. statistics candidate, Joshua Katz, has taken it upon himself to publish some pretty intricate visualizations of Professor Vert Beaux and Scott Golder's linguistics study. Every diction difference from "especially" versus "expecially," what girls call hair ties, to "carmel" versus "caramel" is beautifully illustrated and even detailed down to variances in major cities.