Psych 421 - Sensation & Perception

Chapter 9 - Auditory System - Study Notes

Dr. Carpenter

Rev. 11/98

I.    The Sensory Aspects of Hearing - Auditory Sensation

            A.    What is the auditory stimulus like?

                        1.    Stimulation = tiny changes in air pressure

                        2.    Waves of pressure move the ear drum

                                    a.    pure tone

                                    b.    cycles

                                    c.    sounds

                        3.    Frequency = the number of cycles of pressure in a sound wave per second

                                    a.     Range of human sensitivity?

                                    b.    Absolute Thresholds

                                    c.    Difference Thresholds

                                    d.    Range of most voice sounds?

                                    e.    To what frequency are humans most sensitive?

                                    f.    Complex tones

                              4.    Amplitude = amount of pressure change produced by the waves (pressure measured in dynes)

                                    a.    Wide range of sensitivities to Sound Pressure Levels (SPL)

                                    b.    Measured in decibles (dB)

                                    c.    What is the phase angle?

            B.    What is the auditory system like?

                        1.    Outer ear

                                    a.    Pinna

                                    b.    External Auditory Canal   

                                    c.    Ear Drums and Tympanic Membranes

                        2.    Middle Ear

                                    a.    What are the ossicles, how many are there, what are they called, and what do they do?

                                    b.    What is impedence?

                                    c.    Eustachian tube

                        3.    Inner Ear

                                    a.    Semicircular canals

                                    b.    What is the cochlea, its parts, its function?

                                    c.    What is the organ of corti, and what is its function?

                                    d.    What are the hair cells, where are they, how do they function?

                                    e.    What are the afferent and efferent fibers and what is their function?

                                    f.    What is the difference between cochlear microphonics and otoacoustic emissions?

                        4.    What is the rest of the auditory system?

                                    a.    Auditory nerve - frequency tuning curve

                                    b.    cochlear nucleus, where is it monaural and where is it biaural?

                                    c.    Superior olivary nuclei

                                    d.    inferior colliculus (& superior colliculus) - Tonotopic organization

                                    e.    medial geniculate nucleus

                                    f.    Primary Auditory Cortex - temporal lobe

II.    What kinds of things can go wrong with hearing?

            A.    Tinnitus

            B.    Presbycusis

            C.    Deafness

                        1.    Audiometry

                        2.    Conductive deafness - otosclerosis

                        3.    Nerve deafness - recruitment

        Return to syllabus