Ch. 2: The Human Ear and Simple Tests of Hearing

Question 1

Pathway of Sound for Air Conduction

Answer 1

From environment through ear canal →ear drum → hearing nerve → auditory cortex

Question 2

Pathway of Sound for Bone Conduction

Answer 2

From environment → bones of skull → hearing nerve → auditory cortex

Question 3

The General Parts of the Ear

Answer 3

Outer ear
Middle ear
Inner ear
Auditory cortex

Question 4

Outer Ear

Answer 4

• Pinna – collects/funnels sounds into the ear
• Ext. auditory meatus/canal
• Tympanic membrane (eardrum) – *dividing point between outer and middle ear *

Question 5

Middle Ear

Answer 5

• Ear drum
• Ossicles:
  
  • Malleus
  • Incus
  • Stapes

Question 6

Inner Ear

Answer 6

• Cochlea (Hearing)
• Semicircular canals (balance)
• Auditory nerve (8th cranial nerve)

Question 7

Three Types of Hearing Loss

Answer 7

Conductive HL (air conduction)

Sensorineural HL (air and bone)

Mixed HL

Question 8

Conductive HL

Answer 8

• Conductive hearing loss occurs when there is a barrier in the outer or middle ear
  
  • Attenuation – decrease in the strength of a sound
  • Ex: putting your hand up to silence a bell or covering the ear piece of your cell phone with your hand/hair
  • The BARRIER reduces the volume of the sound

Question 9

Sensorineural HL

Answer 9

• Sensorineural hearing loss occurs when the damage is in the inner ear
  
  • Problem is with bone conduction
  • Sound passes through outer and middle ear with no BARRIER
  • In other words, the hearing loss by air conduction will be the same as bone conduction

Question 10

Mixed HL

Answer 10

• Mixed hearing loss is a result of damage to both the outer/middle and inner ear (combo)
• The damage will result in hearing loss via air conduction due to the BARRIER (as in conductive hearing loss)
• Bone conduction is also affected because the inner ear is damaged too