Psych 421 - Sensation & Perception

Study Notes

Chapter 10 - Basic Auditory Functions

Rev. 11/98

I.    What are the physical and corresponding psychophysical dimensions of audition?

            A.    frequency <-> pitch

            B.    amplitude <-> loudness

            C.    purity (simplicity) <-> timbre

II.    How do we explain our ability to hear pitch?

            A.    Early Theories

                        1.    How does Place Theory account for pitch perception, and who proposed it?

                        2.    How does Frequency Theory account for pitch perception, and who proposed it?

                                    a)    What is a refractory period and why is it a problem for frequency theory?

            B.    What is the evidence supporting place theory and what are some of the problems?

                        1.    Traveling waves - who, what, where?

                        2.    Stimulation deafness experiments

                        3.    Complex waves and timbre

                                    a)    fundamental frequency and

                                    b)    harmonics

                                    c)    Fourier Analysis

                        4.    The Missing Fundamental - What got lost, and how was it found?

            C.    What is the evidence supporting frequency theory and what are some of the problems?

                        1.    Volley Principle:    What and why?

                        2.    Effective frequency range

            D.    Conclusions regarding place and frequency theories

            E.    Complexities in the relationship between frequency and pitch

            F.    Measures of Pitch

                        1.    Octaves

                        2.    Mels

III.    Loudness Perception

            A.    How is amplitude registered?

            B.    Complexities in the relationship between amplitude and loudness

                        1.    Equal Loudness Contours

            C.    Discrimination of Intensities - profile analysis

            D.    Measuring Loudness

                        1.    Musicians' Scale

                        2.    Sone Scale

IV.    How do we localize sounds in space?

            A.    What sources of information are available to the auditory system?

                        1.    Time of Onset

                        2.    Phase Differences

                        3.    Intensity Differences

            B.    Problems - Cone of Confusion

            C.    Measuring Localization Accuracy

                        1.    Minimum Audible Angle

                        2.    Lateralization vs. localization

            D.    Physiological Basis for Localization

                        1.    medial superior olivary nucleus and

                        2.    lateral superior olivary nucleus

            E.    Localization in Non-Humans

                        1.    Barn Owls

                        2.    Bats

            F.    The effects of human vision on auditory localization

V.    Perception of Simultaneous Sounds

            A.    Three effects from sounding two simultaneous tones

            B.    Masking - the critical band and forward and backward masking

            C.    Noise

                        1.    What are the effects of exposure?

                                    a)    deafness

                                    b)    adaptation

                                    c)    fatigue and threshold shifts

                                    d)    others

                        2.    Reduction of noise pollution

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