Toolbox/Inside the Ear
The ear converts pressure waves in air to electrical impulses in nerves
Why Study the Ear?
The spiral cochlea of the inner ear is a delicate structure that distinguishes different frequencies of sound. Fundamentally the ear is concerned with identifying different sources of sound. Distinguishing different frequencies helps.
Other details of the ear give insight into aspects of sound that matter:
- We have two ears. This helps greatly in locating where sounds are coming from.
- The shape of the outer ear (Auricle) adds directionality to our sound sense. Sounds from certain directions are amplified, and the quality of sounds from other directions changed.
- The mechanics of the middle ear allow us to 'turn up or down the gain'. We can choose to listen attentively to a faint sound, or to reduce the impact of very loud sounds.
Chart of Loudness
Equal loudness curves, showing that perceived loudness depends on both air pressure and frequency. Lowest red line is threshold of hearing. We have most sensitive hearing at about 2KHz. Top red line is threshold of pain.