I found this book to be very detailed, technical and while a professional speaker might appreciate it, the beginner would most probably not. Michael McCallion is recognized by many as an authority in the field, as I discovered later, and he painstakingly touches every area one needs to know about voice. However, I felt disoriented with my reading. I needed something to guide me through the complexity of the book and help me set out a plan, but I found none of that. Metaphorically speaking, it was as if instead of a fitness guide, I was reading a medical book.
I found the book too dry to go through all details because I did not know which detail is relevant to me. I kept wondering which exercise I should do, in what order and which ones are suitable for me. In my view this book does a much better service for the initiated such as actors or public speakers or at least people that went through voice training programs before. If you are one of these people, the book offers good material to choose from, including voice exercises.
Another aspect that I found missing from the book was any form of relationship between the author and the reader. There wasn't anything in the book to refer to personal experience, encouragement or advise or something to give you an indication that you will do well (or not), even if you are not a professional speaker. Confidence is a huge factor in any personal improvement enterprise.
The first 100 pages talk about Body, Breathing and Tuning. Most of this is about the anatomy of the body, in a rather scholastic tone. I read it with difficulty mainly because I could not see how I fit into this and I could not identify which part is important for me. The author seems to be very professional and knowledgeable, I suspect he didn't miss much from all the mechanics of voice production, but he did not offer too much help for the reader to make a decision and self-assess the situation.
The next 70 pages are about Speech. After a few pages with technical terms (diagrams showing how the vowels are produced), to my relief, I found finally some practical exercises.
The final section of the book, Using Your Voice, describe in the usual very detailed style, what to do with your voice and how to take care of it. It advises actors, teachers, radio presenters, etc what to do to warm up, on stage and in between.
Overall, I believe this book is more useful for professional speakers (actors, radio presenters, etc) speech trainers looking for inspiration than to uninitiated people.