Stop for a moment and listen, wherever you might be. What do you hear? How noisy or quiet is it? How are you able to tell one source of sound from another? Or where a given sound might be coming from? Or for that matter, what in fact is ‘sound’? Our sense of hearing provides us with a rich means to perceive the world around us, while our voice provides a means to interact with it. The ear itself is a remarkable detector, the study of which combines approaches from many disciplines such as physics, biology, mathematics, psychology, and engineering. This talk will explore answers to the questions posed above from a biophysical point of view, as well as highlight another fascinating aspect of hearing: A healthy ear not only detects sounds, but emits it as well!