Audition (2)

Question 1

What range of sound frequencies can humans hear?

Answer 1

Humans can detect air vibrations between approximately 20 and 20,000 hertz.

Question 2

What is the primary function of the human ear?

Answer 2

To perceive sound by detecting vibrations in the air.

Question 3

How do sound waves travel through the ear?

Answer 3

They move from the outer ear through the auditory canal, causing the **tympanic membrane (eardrum) **to vibrate.

Question 4

What are the three ossicles of the middle ear?

Answer 4

Malleus (hammer), Incus (anvil), and Stapes (stirrup), which transmit vibrations to the oval window then cochlea.

Question 5

What does the stapes vibrate?

Answer 5

The stapes vibrates the oval window, sending vibrations into the fluid of the cochlea.

Question 6

What is the cochlea and what does it contain?

Answer 6

A coiled tube containing the organ of Corti, which converts vibrations into neural signals.

Question 7

What are the key membranes in the organ of Corti?

Answer 7

The basilar membrane, where hair cells sit, and the tectorial membrane, which rests on the hair cells.

Question 8

How do hair cells work?

Answer 8

They are deflected by the tectorial membrane, triggering firing in the auditory nerve.

Question 9

Which nerve carries auditory signals to the brain?

Answer 9

The auditory nerve, a branch of the auditory-vestibular nerve (cranial nerve VIII).

Question 10

How are cochlear vibrations dissipated( come to a stop)?

Answer 10

By the round window, an elastic membrane in the cochlea.

Question 11

Describe the components of the human ear, and explain how sound is processed within its various structures.

Answer 11

• Sound wavs enter the auditory canal and vibrate the tympanic membrane.
• Vibrations pass through the three ossicles (malleus, incus, stapes).
• The stapes sends vibrations into the cochlear fluid through the oval window.
• Fluid movement bends hair cells in the organ of Corti.
• Hair cells convert vibrations into electrical signals sent to the brain via the auditory nerve, where sound is perceived.

Question 12

How sensitive is the human cochlea?

Answer 12

It can detect frequency differences as small as 0.2%.

Question 13

How does the cochlea code different frequencies?

Answer 13

High frequencies stimulate hair cells near the oval window; low frequencies stimulate hair cells at the tip.

Question 14

How are complex sounds encoded?

Answer 14

Many hair cells along the basilar membrane are activated, sending signals via different auditory neurons.

Question 15

What is tonotopic organization?

Answer 15

The auditory system is arranged by frequency, similar to how the visual system is organized by location of light on the retina.

Question 16

What are the semicircular canals?

Answer 16

Receptive organs of the vestibular system, they provide information about head movement and help maintain balance.

Question 17

Describe the major pathways that lead from the
ear to the primary auditory cortex

Answer 17

“Come Over Later, I’m Musical”

Come → Cochlear Nuclei – gets sound from ear

Over → Superior Olives – compares both ears (localization)

Later → Lateral Lemniscus – carries signals up

I’m → Inferior Colliculi – makes sound map

Musical → Medial Geniculate – sends to Auditory Cortex