The first comprehensive guide to the sounds of eastern North American birds, featuring an innovative visual index that allows readers to quickly look up unfamiliar sounds in the field. Bird songs and calls are just as important as visual field marks in identifying birds. But until now, the only way to learn them was by memorization. With this groundbreaking book, it's possible to visually distinguish bird sounds and identify birds using a field guide format. At the core of this guide is the spectrogram, a visual graph of sound. With a brief introduction to five key aspects--speed, repetition, pauses, pitch pattern, and tone quality--readers can learn to visualize sounds, without any musical training or auditory memorization. Picturing sounds makes it possible to search this book visually for a bird song heard in the field. The Sound Index groups similar songs together, narrowing the identification choices quickly to a brief list of birds that sound alike. Readers can then turn to the species account for more information and/or listen to the accompanying audio tracks available online, through Cornell's Lab of Ornithology. Identifying birds by sound is arguably the most challenging and important skill in birding. This book makes it vastly easier to master than ever before.