This book was using English words to show how to pronounce the Esperanto sounds

I had the same problem with a Turkish book. They used words to help explain the vowels...most were OK but check out this example:

A a as the a in cat pronounced by a northern English person; or the u in cup pronounced by a Londoner or Australian.

Whaaa? What if you can't think of how any of those people would pronounce any of those words? What then? Luckily, I had a real live Turk for help!