Interest is immediately captured in this exploration of the causes of high and low Ditched sounds and sustained through several entertaining and highly informative activities. (Have you ever tried to make a tablespoon resonate like a church bell, or a soda straw like a multipitched whistle?) From these experiences Dr. Branley moves to a brief and simple explanation of the physiology of hearing. The illustrations are somewhat humorous and add greatly to the book's enjoyment.