Audition II: Auditory Pathway and Hearing Mechanism

What is the primary function of sound localization?

Which part of the brain is responsible for sound localization?

What is the main cause of conductive deafness?

What is the name of the tube that connects the middle ear to the back of the throat?

What is the name of the disease that causes an increase in the pressure of the endolymph?

What is the name of the antibiotic that can cause nerve deafness?

What is the term for partial or complete reduction in hearing ability?

Which of the following is NOT a type of deafness?

What is the pathway of sound transmission in air conduction?

What is the purpose of masking in audiology?

What is the location of the basilar membrane in the ear?

What is the theory of hearing that explains the transmission of sound waves to the basilar membrane?

What is the type of testing that assesses sensitivity when the signal is transmitted through the bones of the skull to the cochlea?

What is the characteristic of sound transmission according to the travelling wave theory?

What is the representation of hearing in the brain?

What is the type of testing that uses headphones or insert earphones to assess sensitivity?

Auditory Pathway and Mechanism of Hearing

Hearing is bilaterally represented in the brain
Sound transduction and transmission occur through the ear

Theories of Hearing

Travelling wave theory of hearing:
- High-frequency sound is transmitted to the stiff part of the basilar membrane and then dies
- Medium frequency sound waves are transmitted to the middle of the basilar membrane and then die
- Low-frequency sound waves are transmitted to the flexible part of the basilar membrane and then die

Auditory Defects

Deafness:
- Reduction in hearing ability, either partial or complete
- Two main types:
  - Conductive deafness:
    - Results from interference with sound conduction from the air to the cochlea
    - Causes: obstruction of the external ear canal, damage or perforation of tympanic membrane, infection of the middle ear, otosclerosis, blockage of the Eustachian tube
  - Nerve deafness (permanent):
    - Results from interference with the transmission of nerve impulses from the cochlea to the auditory cortex
    - Causes: damage to the basilar membrane or the organ of Corti, damage to the cochlear nerve, Meniere's syndrome, extensive lesions of the auditory nervous pathway

Tests for Detection of Auditory Defects

Air conduction test:
- Assesses sensitivity when the signal is transmitted through the outer, middle, and inner ear and then through the brain to the cortex
- Performed using headphones or insert earphones
Bone conduction test:
- Assesses sensitivity when the signal is transmitted through the bones of the skull to the cochlea and then through the auditory pathways of the brain
- Bypasses the outer and middle ear

Localization of Sound

Ability to detect the source from where sound is produced or the direction through which sound waves are traveling
Important for survival and protection from moving objects
Cerebral cortex and medial geniculate body are responsible for localization of sound

This quiz covers the auditory pathway, mechanism of hearing, theories of hearing, and classification of auditory defects. It's a great resource for students of audiology and otolaryngology.