Eardrum

Definition

The eardrum, also known as the tympanic membrane, is a thin, flexible membrane that separates the outer ear from the middle ear. It plays a crucial role in the process of hearing by transmitting sound vibrations from the outer ear to the middle ear, where they are further processed and interpreted by the brain.

5 Must Know Facts For Your Next Test

1. The eardrum is approximately 9-10 millimeters in diameter and has a surface area of around 55 square millimeters.
2. The eardrum is composed of three layers: an outer layer of skin, a middle layer of fibrous tissue, and an inner layer of mucous membrane.
3. The eardrum is responsible for amplifying sound vibrations by up to 22 times, making it easier for the middle ear bones to transmit the vibrations to the inner ear.
4. Damage or perforations to the eardrum can lead to hearing loss, as it impairs the transmission of sound vibrations to the middle and inner ear.
5. The eardrum is sensitive to changes in air pressure, which can cause it to bulge or retract, leading to a sensation of discomfort or pain.

Review Questions

• Explain the role of the eardrum in the process of hearing.
  • The eardrum plays a crucial role in the process of hearing by transmitting sound vibrations from the outer ear to the middle ear. It acts as a flexible membrane that amplifies these vibrations, making it easier for the three small bones (ossicles) in the middle ear to transmit them to the inner ear. This process is essential for the brain to interpret the sound waves and allow us to hear.
• Describe how the eardrum is affected by changes in air pressure.
  • The eardrum is sensitive to changes in air pressure, which can cause it to bulge or retract. When the air pressure on the two sides of the eardrum is not equal, it can lead to a sensation of discomfort or pain. This is commonly experienced during air travel or when diving underwater, as the changing atmospheric pressure affects the balance of pressure on the eardrum. The eardrum's ability to adjust to these pressure changes is crucial for maintaining proper hearing function.
• Analyze the relationship between the eardrum and sound intensity, and how this affects our perception of sound.
  • The eardrum plays a vital role in the perception of sound intensity. As sound waves reach the eardrum, it vibrates in response to the varying pressure of the sound. The eardrum's ability to amplify these vibrations by up to 22 times allows the middle ear bones to more effectively transmit the sound energy to the inner ear. This amplification process is essential for our ability to perceive a wide range of sound intensities, from the faintest whispers to the loudest noises. The eardrum's sensitivity to sound intensity is a key factor in our overall hearing experience and our perception of the world around us.

Related terms

Outer Ear: The external part of the ear that collects sound waves and directs them towards the eardrum.

Middle Ear: The space behind the eardrum that contains the three small bones (ossicles) responsible for transmitting sound vibrations to the inner ear.

Sound Intensity:

The amount of sound energy passing through a unit area, measured in watts per square meter (W/m²).