Would it not have been easier to use the International Phonetic Alphabet to describe the basic sounds in the relevant exercises?
The International Phonetic Alphabet is a useful method for learning the pronunciation of foreign words or learning how to pronounce unfamiliar words in a dictionary. However, before one uses a dictionary one must first of all be able to read and spell. The I.P.A. does not account for regional variations. In order to overcome this problem Toe by Toe uses examples of words containing a particular skill.