Ear

• Explaining hearing:

  • pinna traps sound waves
  • into ear canal
  • causes tympanic membrane (A) to vibrate
  • vibration is transmitted to ossicles (B)
  • ossicles amplify the vibration
  • and transmit it to the oval window (C)
  • the oval window vibrates, creating waves
  • in endolymph/fluid of the cochlea (D)
  • which stimulates organ of Corti (E)
  • to convert wave into an impulse
  • impulse travels along auditory nerve (F)
  • to cerebrum, where interpreted as sound

  
• What is the functiopn of the ossicles?

  amplification
• What does moving from a large to small surface area do to sound?

  Concentrates it
• Explaining amplification:

  • the sound vibrations are transmitted from the large tympanic membrane (A)
  • to the smaller oval window (B)
  • through the ossicles (C)
  • which are arranged from largest to smallest
  • this concentrates the vibrations, amplifying them
• Label the ear:

  1. pinna
  2. ear canal
  3. tympanic membrane (ear drum)
  4. ossicles
  5. oval window
  6. semi-circular canal
  7. cochlea
  8. auditory nerve
  9. Eustachian tube

  
• Which structure in the ear converts sound waves into mechanical movement?

  Tympanic membrane
• Give the function of the ossicles.

  Amplification of sound
• How does the surface area of the membranes in the ear influence hearing.

  Moving from a large surface area to a small surface area amplifies the sound for clear hearing.
• The function of the round window is to allow excess sound waves to escape the ear preventing reverberation.