Review Final

Question 1

Frequency selectivity:

Answer 1

Clearest when
sounds are very faint

Question 2

Threshold tuning curve:

Answer 2

A graph plotting
thresholds of a neuron or fiber in response
to sine waves with varying frequencies at
the lowest intensity that will give rise to a
response

Question 3

How does encoded frequency change with distance down the Cochlea?

Answer 3

Characterisic frequency (Hz) varies with position in organ of corti

Question 4

Phase locking:

Answer 4

Firing
of a single neuron at
one distinct point in the
period (cycle) of a
sound wave at a given
frequency

Question 5

Temporal code:

Answer 5

Tuning of different
parts of the cochlea to different
frequencies, in which information about
the particular frequency of an incoming
sound wave is coded by the timing of
neural firing as it relates to the period of
the sound

Question 6

The volley principle

Answer 6

An idea stating
that multiple neurons can provide a
temporal code for frequency if each
neuron fires at a distinct point in the
period of a sound wave but does not fire
on every period

Question 7

sounds localized in space by (3):

Answer 7

(1)Azimuth
coordinates
(2):Elevation
coordinates
(3):Distance
coordinates -

Question 8

Azimuth
coordinates -

Answer 8

position left to right.

Question 9

Elevation
coordinates -

Answer 9

position up and down

Question 10

Distance
coordinates

Answer 10

observer.

Question 11

Binaural cues

Answer 11

location cues based on the
comparison of the signals received by the left and
right ears.

Question 12

Medial superior olive (MSO):

Answer 12

A relay station in the brain stem
where inputs from both ears contribute to detection of ITDs.
ITD detectors form connections from inputs coming from two
ears during the first few months of life.

Question 13

Interaural level difference (ILD):

Answer 13

The difference in level (intensity)
between a sound arriving at one ear versus the other

Question 14

For frequencies greater
than 1000 Hz, the head

Answer 14

blocks some of the energy
reaching the opposite ear

Question 15

ILD is largest at

Answer 15

90
degrees and –90 degrees

Question 16

ILD nonexistent for:

Answer 16

0 degrees
and 180 degrees

Question 17

ILD generally correlates
with

Answer 17

angle of sound
source, but correlation is
not quite as great as it is
with ITDs

Question 18

ILD generally correlates
with angle of sound
source, but correlation is

Answer 18

not quite as great as it is
with ITDs

Question 19

Lateral superior olive (LSO):

Answer 19

A relay station in the brain stem
where inputs from both ears contribute to the detection of ILDs

Question 20

Excitatory connections to LSO come from

Answer 20

ipsilateral ear

Question 21

Inhibitory connections to LSO come from

Answer 21

contralateral ear

Question 22

Cone of
confusion:

Answer 22

A
region of
positions in
space where all
sounds produce
the same ITDs
and ILDs
Experiments by
Wallach (1940)
demonstrated
this problem

Question 23

Head-related transfer function (HRTF):

Answer 23

A function that describes how the pinnae, ear
canals, head, and torso change the intensity of sounds with different frequencies that arrive
at each ear from different locations in space (azimuth and elevation)

Question 24

Each person has their own ___ and uses it to help locate sounds

Answer 24

HRTF (based on their own body)

Question 25

Each semicircular canal is about __ shape, measuring _ long and __ in diameter

Answer 25

Each one is about three-fourths of a toroid
(donut) shape, measuring 15 mm long and 1.5
mm in diameter

Question 26

Semicircular canals are filled with

Answer 26

a fluid called perilymph

Question 27

A second, smaller __ is found inside the __ toroid, measuring ___

Answer 27

A second, smaller toroid is found inside the
larger toroid, measuring 0.3 mm in diameter

Question 28

the second, smaller toroid is formed by :

Answer 28

a membrane filled with
fluid called endolymph

Question 29

Cross section of each canal swells substantially
near where the canals join the vestibule:

Answer 29

Ampulla

Question 30

Within the endolymph space of each ampulla is the

Answer 30

crista

Question 31

Cristae:

Answer 31

The specialized detectors of angular motion located in each
semicircular canal in a swelling called the ampulla.

Question 32

Each crista has about

Answer 32

7000 hair cells and associated
supporting cells and nerve fibers.

Question 33

Cilia of hair cells project into

Answer 33

a jellylike cupula that forms an
elastic dam extending to the opposite wall of the ampulla, with
endolymph on both sides of the dam.

Question 34

When the head rotates, the ___ causes it to lag behind, leading to tiny deflections of the hair cells

Answer 34

inertia of the endolymph

Question 35

__ semicircular canals in each ear

Answer 35

3

Question 36

each canal is oriented in __

Answer 36

a different plane

Question 37

each canal is maximally sensitive to :

Answer 37

rotations perpendicular to the canal plane

Question 38

Hair cells in opposite ears respond in a

Answer 38

complementary fashion to each
other

Question 39

When hair cells in the left ear depolarize, those in the analogous structure
in the right ear

Answer 39

hyperpolarize

Question 40

Neural activity in semicircular canals is sensitive to

Answer 40

changes in rotation
velocity

Question 41

Constant rotation leads to:

Answer 41

decreased responding from the canal neurons after a few seconds

Question 42

__otolith organs in each ear

Answer 42

Two

Question 43

Utricle contains about:

Answer 43

30,000
hair cells.

Question 44

Saccule contains about:

Answer 44

16,000
hair cells.

Question 45

each otolith organ contains a :

Answer 45

macula

Question 46

macula:

Answer 46

detector of linear acceleration and
gravity, sensitive primarily shear
forces.

Question 47

Hair cells are encased in

Answer 47

a gelatinous structure that contains
calcium carbonate crystals called
otoconia.

Question 48

Hair cells are encased in a
gelatinous structure that contains
calcium carbonate crystals called

Answer 48

otoconia

Question 49

Larger accelerations (or larger
gravitational shear forces) move the
otolith organ’s otoconia __

Answer 49

more

Question 50

Larger accelerations (or larger
gravitational shear forces) move the
otolith organ’s otoconia more.This leads to

Answer 50

greater deflection of the hair
cell bundles.

Question 51

Coding of amplitude in the otolith organs:Change in receptor potential is
proportional to

Answer 51

magnitude of linear
acceleration or gravitational shear.