David and I discuss five of the 11 vowels of American English, and go over the various ways each sound can be spelled.  This leads to discussions of the International Phonetic Alphabet (IPA) and spelling bees (David won his school spelling bee!).  The idioms 'rule of thumb' and 'off the top of my head' come up in conversation.  Vowels covered:  AH [ɑ], AW [ɔ], AA [æ], EE [i], IH [ɪ].