MODULE 9: The outer Ear

Question 1

What system is responsible for sensing and coding sound ?

Answer 1

Peripheral auditory system

** this is what we will be concentrating on in this class

Question 2

What system is responsible for processing sound and deriving meaning from it?

Answer 2

central auditory system

Question 3

The peripheral system is divided into three section: What are they?

Answer 3

The outer, middle and inner ear

Question 4

The outer ear is called?

Answer 4

The Pinna (Auricle)

Question 5

The passageway into the body is known as the ?

Answer 5

External auditory Meatus or the EAR CANAL

Question 6

All of the ridges and valleys on your outer ear (PINNA):

a) create resonance that affect the amplitude of sound
b) protect the ear from foreign objects to enter the ear

Answer 6

a) create resonance that affect the amplitude of sound

Question 7

The Pinna is composed primarly of?

Answer 7

cartilage

Question 8

Whether the sound resonantes or is reflected depends on the angle from which the sound is coming at the ear. True or false?

Answer 8

TRUE

Question 9

Which part of the Pinna has the largest effects on the amplitude spectrum of incoming sound?

Answer 9

The CONCHA

Question 10

Your head creates a shadow called?

Answer 10

head shadow

Question 11

The head shadow is only effected by what kinds of sounds?

Answer 11

high frequency sounds

Question 12

Sounds with wavelengths shorter than the width of your head also produce a head shadow..EXCEPT, that the ear on the side of your head closest to the source of sound?

Answer 12

Hears the sound best. The other ear experiences the sound greatly reduced in amplitude

Question 13

For most people, frequencies above ______HZ are affected by the head shadow.

Answer 13

1600

Question 14

The meatus (aka the ear canal) ends at the ?

Answer 14

Ear drum

Question 15

The resonances of the ear canal increases sound levels for frequencies between ____-____HZ, with a peak gain of __db at _____-____HZ

Answer 15

2000-5000 HZ
15 db
3000-4000 HZ

Question 16

The outer ONE THIRD of the ear is composed of?

Answer 16

cartilage with hair follicles and ceruminous glands that produce cerumen (aka ear wax)

Question 17

True or false: The cerumen ( Ear wax) lubricates the ear, helps to remove dead skin cells and changes the pH level of the ear canal to be slightly more acidic.

Answer 17

True

Question 18

The inner two thirds of the ear canal is encases in the ____ bone of the skull and is on the edge of the ___(2)____ joint.

Answer 18

1. temporal bone

2. temporo-mandibular joint

Question 19

What shows changes in sound level due to the presence of the head, pinna, ear canal , shoulders and chest as a function of frequency ?

Answer 19

HEAD-RELATED TRANSFER FUNCTION (HRTF)

Question 20

What is used for sound localization when two ears are present?

Answer 20

Binaural cues

Question 21

What reduces sound levels (( at the far ear)) for frequencies ABOVE 1600 HZ when the source is on the opposite side of the head.

Answer 21

The head shadow effect

Question 22

What increases sound levels for frequencies between 2000-5000 HZ, with a peak gain of 15 dB at 3000-4000 HZ?

a) head shadow effect
b) ear canal resonance
c) pinna effects

Answer 22

b) Earl canal Resonance

Question 23

What alters the amount of gain for frequencies greater than 4000 HZ?

Answer 23

The pinna

Question 24

What is the ridge along the outer edge of the pinna called:

1) tragus
2) helix
3) concha
4) external auditory meatus
5) Lobe

Answer 24

4) external auditory meatus

Question 25

The head shadow effect increases the level of some sounds on the side of the head opposite of the sound source :

True or false

Answer 25

False

Question 26

Which of the following statements about the head related transfer function is false:

a) the head related transfer function includes effects from the torso, shoulder, head, pinna, and ear canal
b) the head related transfer function varies from person to person
c) the head related transfer function is the same, no matter what direction the sound is coming from
d) The amount of gain or loss to sound varies by frequency

Answer 26

c) the head related transfer function is the same, no matter what direction the sound is coming from