In this nonfiction text, readers learn how sounds are made, the mechanisms of the ear, and ways in which sound can be recorded and replayed. An explanation of deafness, hearing devices, the speed of sound, soundproofing, speech and song in humans and animals, and seismology are included along with photographs, charts, timelines, and illustrations. A short introduction discusses what the reader will learn and tells about the blue feature boxes that appear throughout the book. There are "Did You Know" facts, "Test Yourself" questions, "Investigate" experiments, and "Time Travel" discoveries. Answers to the "Test Yourself" and "Investigate" feature, an index, and a glossary are included at the end. Words that are highlighted in bold print throughout the text are found in the glossary. This text in the "Fundamental Physics Series" provides essential information in a relevant format and is a good source for the study of these sciences.