This website is a great resource for teachers and students alike to understand phonemic differences within different dialects of English.  The clickable accent chart allows you to hear a multitude of words pronounced by English speakers in various regions of Canada, the U.S., England, Australia, New Zealand, Scotland and Ireland, as well as by speakers of world Englishes from countries such as India, Hong Kong, the Philippines, Trinidad and more.  The clickable accent map will open links to ultrasound  video recordings of speech samples from various regions around the world.