Research in the growing field of sensory studies has begun to identify the sensory aspects of experience, particularly in our engagement with material culture. What is yet to receive much attention is how the senses are acquired and used by individuals and communities, and how they inform action. Adopting Barth’s argument that cultural phenomena are most productively examined as different kinds of knowledge, this article argues that the senses can be examined as any other knowledge source. This article demonstrates the value of examining the senses as knowledge through an account of learning to hear medically. This example is taken from a broader ethnographic study of the aural practices and experiences of ninety-two musicians, doctors, adventurers, and Morse code operators. It argues that hearing is learned, specialized, and specific to the places we go, the people that surround us, and the things that we do. To seek out the sources and value of this taken-for-granted aspect of our experience, it argues that the senses can be analyzed in terms of their foundations, their acquisition, and practice.