Pitch Perception

Define pitch

the perceptual correlate of frequency that can not be measured directly

True or false: pitch equals frequency

false

Pitch is important for what?

speech and music perception

Name the average frequency for a male voice

130 Hz

Name the average frequency for a female voice

260 Hz

Name the average frequency for a child voice

400 Hz

Define pure tone

only contains one frequency

Define complex tone

combination of multiple tone

Name the characteristics of harmonic complex tones

many sounds we encounter

repeated over time

repetition rate determined by fundamental frequency

contains fundamental frequencies and overtones

pitch of harmonic corresponds to fundamental frequency

Name the characteristics of resolved harmonics

low numbered harmonics

harmonics that have separation representation in the cochlea

can be heard out by listeners

Name the characteristics of unresolved harmonics

high numbered harmonics

do not produce individual peaks of excitation

can not typically be heard out

Name the characteristics of auditory filters of harmonic complex at 2000 Hz

unresolved harmonics auditory filters closer together

resolved harmonic auditory filters are further apart

Name the characteristics of excitation patterns of harmonics

resolved harmonics look more squiggly

unresolved harmonics are in a line

Name the characteristics of low numbered (resolved) harmonics

resemble pure tone

each of them generates different firing patterns of auditory nerve

Name the characteristics of high number (unresolved) harmonics

no longer resembles pure tone

produce complex waveform and amplitude modulation

How is pitch change measured with frequency?

magnitude estimation method

Name the scale used in magnitude estimation method

mel scale

How many mels are in a 1000 Hz tone?

1000 mels

Fill in the blank: pitch increases when frequency increases, but not in a _________ relationship if above 1000 Hz

linear

What is the pitch perception at high frequencies?

pitch increases with an increase in intensity

What is the pitch perception at mid-frequencies?

pitch does not change with a change in intensity

What is the pitch perception at low frequencies?

pitch decreases with increase of intensity

What is the difference in frequency difference limen?

FDL at 1000 Hz at 40 dB SPL was found to be ~2 Hz

What is weber’s fraction for frequency discrimination?

difference of frequency / frequency

Fill in the blank: weber’s fraction is ___ constant

not

Frequencies below 1500 Hz cause weber’s fraction to do what?

decrease with frequency

Frequencies above 1500 Hz cause weber’s fraction to do what?

increase with frequency

True or false: the higher the frequency the wider the critical bandwidth which makes it hard for frequency discrimination

true!

Name the characteristics of place code model

reflects the mechanical filtering happening in cochlea

pitch is determined by the place of maximum excitation of the basilar membrane

each place along the basilar membrane responds the best to its own characteristic frequency

Name the characteristics of temporal code model

relies on the phase locking of the auditory nerve fibers

frequency can be represented by the time intervals between successive spikes in multiple nerve fibers aka action potentials

What problem arises in temporal code theory?

phase locking in mammals is only up to 5000 Hz the even with a combination of mutliple AN fibers

Name the characteristics of place coding for complex tones

the pitch of a complex tone is determined by the place of maximum excitation within the cochlea

pitch is extracted from resolved harmonics

resolved harmonics always need to be present

resolved harmonics have their own representation in the cochlea

Name the characteristics of temporal coding for complex tones

depends on the fundamental frequency

resolved harmonics are required to phase lock to the temporal fine structure

unresolved harmonics phase lock to envelope

the same inter-spike interval regardless of resolved or unresolved harmonics

resolved harmonics don’t always need to be present for pitch perception

Fill in the blank: complex tones containing the first _____ harmonics are resolved harmonics

ten

Fill in the blank: complex tones containing only harmonics __________ are unresolved harmonics

4-10

Define missing fundamental

the smallest detectable difference in fundamental frequency

Fill in the blank: excellent fundamental frequency discrimination when ___ frequency harmonics are present

low

True or false: it is difficult to discriminate the fundamental frequency after removing low frequency harmonics

True

Define the place code theory

pitch of complex tones rely on the detection of fundamental frequency and resolved harmonics

Define temporal code theory

discusses how it might work better to explain perception when missing the fundamental frequency

Name the problems that arise in place code theory

pitch can still be heard when only unresolved harmonics are presented

can not explain the pitch of the missing fundamentals

Name the problems that arise in temporal code theory

pitch can still be perceived if all the frequencies are above the upper limits of phase locking

Fill in the blank: pitch perception of a harmonic complex tone is primarily determined by the first _______ harmonics, and are usually resolved harmonics

5-8

Fill in the blank: the auditory systems need to combine and _________information from these harmonics

synthesize