~Chapter 11 - Lecture Section 11.4

Question 1

Pitch perception is the variation in sound perceptually associated with ___.

Answer 1

musical melodies

Question 2

Why can Pitch perception not be as simple as just the Place Theory?

Answer 2

The main reason for this is the effect of the missing fundamental/Periodicity Pitch, where if you play a complex tone, and remove the Fundamental, therefore the peak in the Basilar Membrane is gone, and so the activation pattern according to strict Place Theory would be changed, but yet we still perceive this sound as having the same pitch.
Therefore, simply measuring where the peaks in the Basilar Membrane activation are located and saying that produces a perceptive pitch cannot be true because when you change the stimulus, but the percept does not change, disproves this theory

Question 3

We can modify the Place Code, because we know the Fundamental frequency can still be determined by measuring the separation of ____ on the cochlea. But rather than doing it on a Frequency Spectra, instead, we measure the separation of ___ on the Cochlea itself, this qualifies as a ___. We could also use the timing of ___ to pick out the different frequencies and detect the spacing between those frequencies.

Answer 3

peaks/Harmonics // Harmonics // Modified Place Code // neural firing (temporal coding)

Question 4

Another piece of evidence indicates that melodies with notes above ___Hz do not sound musical, but melodies with notes that are below ___Hz still sound musical, indicates that probably has more to do with the ___ Code, because the ___ Code stops being effective after ___Hz, but the ___ Code does not.

Answer 4

5000 // 5000 // Timing // Timing // 5000 // Place

Question 5

Pitch perception mostly occurs for frequencies below ___Hz, which is also the limit of ___. Therefore, ____ Coding is probably the main determinant of pitch perception

Answer 5

5000 // Phase Locking // Temporal

Question 6

Tuning of Auditory nerve fibers is ___ at high Frequencies, and ___ at low Frequencies .

Answer 6

wider // narrower

Question 7

Auditory filterbank is a collection of auditory nerve cells that have their ___, and also have tuning ___. For low frequencies, the tuning width is ___. For high frequencies, the tuning width is quite ___.

Answer 7

characteristic frequencies // widths // low // broad

Question 8

Fundamental + lower/second Harmonics activate different/distinct “filters” and will produce a ___ activation. When you have narrowly spaced harmonics that are activating broadly tuned curves, they will produce a ___ line. Higher harmonics activate multiple/a few large ___ “filters”.

Answer 8

wiggly // flat // overlapping

Question 9

What is “Excitation pattern”?

Answer 9

The summation of all of the activity produced from the complex tone/sum of filter activity

Question 10

For Resolved Harmonics that activate discrete filters, the Second Harmonic and the Fundamental activate ___ filters, there’s one that’s left ___ in between. Harmonics that produce ___ in the excitation pattern. Produce ___ perception of pitch.

Answer 10

discrete // unstimulated // peaks // strong

Question 11

Unresolved Harmonics will activate ___ tuned curves, that interact within the same filters to create a ___ perception of pitch and a ___ excitation pattern. They are Harmonics that produce ___ in excitation pattern. They produce ___ perception of pitch.

Answer 11

broadly // weak // smooth/flat // smooth activity // weak

Question 12

The difference between Resolved and Unresolved Harmonics has to do with the different ___ of the ___ along the Basilar Membrane, and is very much related to the ___ of pitch perception.

Answer 12

widths // tuning curves // Place Code

Question 13

The Primary Auditory Cortex is called ___.

Answer 13

A1

Question 14

There is ___ organization in Cortex (A1).

Answer 14

Columnar

Question 15

A1 consists of a ___ area, ___ area, and a ___ area that are ___ organized, neurons in the same column have the same characteristic frequency (Tonotopic maps). There is orderly organization of ___.

Answer 15

Core // Belt // Parabelt // Tonotopically // characteristic frequency

Question 16

Lesion studies show that monkeys can learn to discriminate ___ even when auditory cortex is lesioned completely. Tonotopy that also exists in ___ areas is enough for ___ discrimination

Answer 16

Pure tones // pre-cortical // Pure tone

Question 17

The Auditory Cortex is responsible for the analysis of more ___.

Answer 17

complex sounds

Question 18

Evidence for Complex Auditory analysis comes from Marmoset Pitch Neurons, which respond to ___ or ___.

Answer 18

characteristic Frequency // periodicity pitch stimuli

Question 19

In a study describing Marmoset Pitch neurons, stimuli that consisted of either the Fundamental, or the triplets of Harmonics were played. The key is, for the first stimulus, there is a regular spacing based on the Harmonic, for the second stimulus, there is the spacing but there is no fundamental that is played, same with the rest. And they all contain these different frequencies, yet, the response of a pitch neuron is ___ to all of them. So these different periodicity pitch stimuli can be made up of very ___ frequency components, but they’re always spaced by the ___, and they always produce the same response in these neurons. In humans, they are also perceived as having the same pitch.

Answer 19

the same // different // fundamental

Question 20

There is evidence of more complex processing happening in the Auditory Cortex, it’s not only the ___ organization of single Pure Tones, but it is combining tones together to measure things like the ___ and ___.

Answer 20

Tonotopic // Effect of the Missing Harmonic // Periodicity Pitch

Question 21

In a study looking at Complex Auditory analysis in the human Cortex, they used an fMRI and used 2 stimuli that had the same ___. They used a stimuli that produced ___, and a stimulus that consisted of ___. It was already known that the Auditory Cortex has the Tonotopic map, and so they needed to distinguish between ___ and just Tonotopic map representation because ___ stimuli will evoke the percept of pitch and Unresolved won’t.

Answer 21

Freqeuncy range // Resolved Harmonics // Unresolved Harmonics // Pitch processing // Resolved

Question 22

Areas most responsive to pitch (prefer ___) were located in the ___ auditory cortex, and as you moved ___, the cells became ___ responsive to pitch

Answer 22

Resolved harmonics // anterior // posterior // less

Question 23

We can see from the study of Complex Auditory Analysis using fMRI that Cortex is making use of info available through the ___ – that’s why there’s a difference between Resolved vs Unresolved Harmonics – in addition to the ___.

Answer 23

Place Code // Temporal Code

Question 24

___ hair cell damage is more common than ___ hair cell damage and is due to ___ drugs that can poison the ___.

Answer 24

Outer // inner // ototoxic // Cochlear Amplifier

Question 25

Outer hair cell damage produces Basilar membrane peak oscillations that become ___ and ___. Therefore, perceptually this produces a loss of ___ and difficulty discriminating ___.

Answer 25

shorter // broader // sensitivity // sounds/similar frequencies

Question 26

___ hair cell damage can occur in a number of different ways, mostly from listening to sounds that are too ___.

Answer 26

Inner // loud

Question 27

Inner hair cell loss can be ___, which leads to decreased sensitivity to all ___. Or it can be specific to a particular ___, so a specific location/region along the Basilar Membrane will lead to a ___ for particular frequencies.

Answer 27

generalized // frequencies // frequency Band // “dead zone”

Question 28

What is Presbycusis?

Answer 28

Presbycusis means “old ear”, and has parallels to the visual system, Presbyopia, “old eye”.

Presbycusis is the cumulative effect of hair cell damage over a lifetime of noise that happens in all of us.

Question 29

What accelerates Presbycusis?

Answer 29

• Exposure to certain drugs/ototoxic drugs (e.g. certain antibiotics or diuretics)
• Loud noises (loud music, firing guns, working in a factory)

Question 30

Presbycusis preferentially affects ___, and so your hearing loss trails off as you get older more dramatically for ___

Answer 30

higher frequencies // high frequencies

Question 31

What is Accelerated Presbycusis?

Answer 31

Where your hearing loss occurs sooner than normal if you’re exposed particularly to excessive noise.

Question 32

Resolved Harmonics produce ___ in the excitation pattern, and produce ___ perception of pitch.

Answer 32

peaks // strong

Question 33

Unresolved Harmonics produce ___ activity in excitation pattern, and produce ___ perception of pitch.

Answer 33

smooth // weak