What we hear can create a mood, build communication, and guide our physical movement. In this episode, series host and naturalist Diane Ackerman investigates musical communication in the movies, in relationships with babies, and in Maori culture. She presents information about how our ears process and protect us from sounds, and explores new medical technology that mimics some of those functions to enable deaf people to hear. She also studies the hearing abilities of several types of animals and discovers how an owl uses its ears to locate prey in total darkness.