Midterm

Question 1

Fletcher

Answer 1

• cochlea processes frequency info in “chunks along the length of the BM
• proposed that BM can be thought of as a number of narrow bandpass filters arranged serially by frequency
• bandwidth becomes wider as center frequency increases (wider, HF @ base; narrow, LF @ apex)
• hypothesized that if ear presented w 1000 Hz pure-tone, signal would be represented in critical band filter centered at 1000 Hz
• delta F is constant proportion of the CBW - do the traveling waves of the two incoming sounds peak at the same place or close on the BM or in different places? (can’t account for SL)

Question 2

Fechner

Answer 2

• founder of experimental psychology
• outlined procedures for measurement of thresholds and one approach to scaling
• method of limits, constant stimuli and adjustment
• “the stimulus energy that lifted the sensation… over the threshold of consciousness”

Question 3

minimum audible pressure (MAP)

Answer 3

• monaural
• sound pressure at the level of the TM w a mic in the ear canal
• dashed line

Question 4

minimum audible field (MAF)

Answer 4

• binaural
• measurement of sound level is made after the listener is removed from the sound field
• solid line

Question 5

Viemeister and Wakefield

Answer 5

• multiple looks
• eliminates conflict btwn short time constant for gap detection and long time constant for temporal integration
• predictions of the two models are similar
• if you’re hearing it for a while, you’re getting better at detecting it

Question 6

Levitt’s procedure

Answer 6

• transformed up-down methods in psychoacoustics
• start at some level above threshold and go down in level after 2 correct responses
• go up in level after each incorrect response
• reversal points will bracket 71% correct
• variation of methods of limits

Question 7

Marshal and Jesteadt

Answer 7

• tested 4 groups of subjects (young/old; hearing loss/normal)
• tested at HF and LF using standard clinical and adaptive procedures
• Yes-No procedure to measure degree of response bias (pt know’s when the signal was presented)

Question 8

sensitivity

Answer 8

likelihood of identifying someone w the disease

Question 9

specificity

Answer 9

the fraction of correctly identifying (normal)

Question 10

step function

Answer 10

ideal psychometric function

Question 11

resonance or place theory

Answer 11

the inner ear acts as a tuned resonator which extracts a spectral representation of the incoming sounds which it passes via the aud nerve to the brainstem and the aud cortex

Question 12

frequency theory

Answer 12

a complete time domain representation of the incoming waveform is directly encoded in the pattern of firings of the aud nerve

Question 13

Zwicker

Answer 13

changes in excitation pattern when frequency is changed

Question 14

Siebert

Answer 14

takes into account statistical variability of the neural representation of the signal (can’t account for frequency effect)

Question 15

Luce & Green

Answer 15

looked at multimodal aud nerve fiber histograms to estimate the period of the signal (can’t account for SL effect)

Question 16

Stevens

Answer 16

long duration tones below 1000 Hz decrease in pitch with increasing intensity and tone above 2000 Hz increase in pitch

Question 17

Rossing & Houtsma

Answer 17

40 ms bursts decrease in pitch with intensity for frequencies of 200-3200 Hz

Question 18

Doughty & Garner

Answer 18

12ms bursts

Question 19

pattern recognition

Answer 19

assumes pitch of a complex tone is derived from neural information about the frequencies/pitches of individual partials

Question 20

temporal model

Answer 20

pitch of a complex tone is related to time intervals between nerve spikes in the 8th nerve, or the periodicity of the total waveform

Question 21

Ritsma

Answer 21

found that pitch is dominated by the 3rd - 5th harmonics when F0 is around 100-400 Hz