Hearing

Introduction

This unit examines the basic mechanisms responsible for our ability to hear. Humans are able to distinguish a remarkable range of sounds and hearing provides us with a unique source of information about what is occurring in our immediate surroundings. Our sense of hearing depends entirely on the sensory receptors of the inner ear known as hair cells. Hair cells are extremely vulnerable and can be affected by disease, ageing and over-exposure to loud noise. Once destroyed, they do not regenerate. In this unit we describe in detail the function of the cochlea, which is where the hair cells are located. We learn how sound energy is transduced into electrical signals and how a rapid-fire code of electrical impulses about the physical characteristics of a particular sound is sent to the brain. The brain interprets these signals as a musical phrase, a human voice or any of the range of sounds in the world around us at a particular moment. We also examine the central auditory nervous system pathways and describe the physiological mechanisms responsible for our sense of pitch and loudness and our ability to localise the source of a sound stimulus. Finally, we look at the main types of hearing impairment and their causes, effects and rehabilitation.

This unit is an adapted extract from the course Signals and perception: the science of the senses(SD329) [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)]