Phonetic survey
John Wells is preparing the 3rd edition of the Longman Pronunciation Dictionary (see more on his blog). For that purpose, he’s asking native speakers of English to complete this survey.
It’s quite an interesting one, and I recommend reading it, even if you (like me) are not qualified to complete it.
Question 20, alas, doesn’t work for speakers of Scottish English. I’m a bit surprised he hasn’t spotted that himself, given he’s the author of Accents of English (which I can highly recommend).