Pitch

What evidence is against the temporal theory?

- dominant region - cross-ear pitch

What evidence is there against the place theory?

- near threshold listening - pitch shift - masking

If our range of pitches were represented in piano keys, there would need to be _____ more notes between each key.

29

In psychoacoustics, neurons are able to phase-lock up until what frequency?

4 kHz

(T/F) Most sounds that give a sensation of pitch are aperiodic.

False - periodic

Who proposed the temporal theory of pitch perception?

Schouten

(T/F) Musical pitch (melody) is absent above 4.5 kHz?

True

(T/F) The pitch of a complex periodic tone is close to the pitch of a sine wave at the fundamental.

True

What is our threshold for frequency discrimination?

approximately 2 Hz at 1000 Hz

Describe the dominance region of pitch perception.

changes in the frequency components in the dominant region influence the pitch of a complex sound more strongly than in any other frequency region; thus, unresolved harmonics should provide the clearest temporal information for pitch perception - proposal: high frequencies have unresolved harmonics, so they must be the dominant region - results: dominant region is 600-1400 Hz where the harmonics are unresolved - argues against Schouten

Describe place code.

different locations on the BM vibrate maximally to different frequencies - neurons are labeled in terms of frequency along the BM - encodes frequencies above 4 kHz

Describe near threshold listening.

high level sounds can produce distortion but low level sounds do not - result: listeners can still detect a virtual pitch with low level sounds, so virtual pitch cannot be attributed to distortion

According to the place theory, pitch is based on the ________ level low frequency component.

highest - aka the fundamental frequency

Describe how masking noise provides evidence against the place theory.

if pitch is being carried by the distortion product produced, then there should be no pitch when distortion is masked - result: we can hear pitch when the distortion product is masked

Describe pitch shift.

if the same amount of distortion is produced by two frequencies, then the pitch shift should be constant - result: producing distortion of 200 Hz resulted in a range of pitches

Low frequency tones are encoded by ______, while high frequency tones are encoded by ______.

low frequency = temporal and place code high frequency = place code (only)

Describe the volley theory.

multiple neurons phase-lock one stimulus together - encodes frequencies between 1-4 kHz

What are harmonics?

multiples of the fundamental frequency

What is pitch?

perception of frequency - attribute of auditory sensation in terms of which sounds may be ordered on a musical scale

According to the temporal theory, pitch is based on the _______ of a waveform.

period (timing)

Describe temporal code.

phase-locking - neurons fire in a systematic way in relation to the stimulus (its period) - occurs during the compression portion of a stimulus - encodes frequencies below 1 kHz

What is pitch pattern recognition theory?

pitch is determined by a pattern recognition process on the resolved harmonics from both ears - proposed by Goldstein - brain finds the best-fitting harmonic series (template) to the resolved frequencies and takes its fundamental as the pitch - first estimates frequencies of individual components of a complex sound

What is virtual pitch?

pitch of missing fundamental frequency - explains why we are able to hear each other's voices on the phone since the microphone sensitivity is only 300-3,000 Hz

Describe cross-ear pitch perception.

proposes that virtual pitch is heard because the brain times the intervals between beats of unresolved harmonics of a complex sound - results: listeners can still hear a virtual pitch when two components are presented to different ears, indicating that the components do not need to interact temporarily in the cochlea

What did Helmholtz propose in opposition to Seebeck's experiment for pitch theory?

suggested that the ear re-introduces energy at the fundamental by a process of distortion - energy is produced from the difference of the two frequencies presented - favored place theory

How is pitch encoded in the auditory system?

temporal and place coding

Seebeck's siren experiment provided evidence for which theory of pitch encoding?

temporal theory - the sirens that produced the same period also produced the same pitch