Physiology Quiz: Physiology of Hearing - Part 16

Physiology Quiz -
Physiology of Hearing - Part 16

The auditory system is responsible for converting sound waves in the environment into electrical signals that the brain can receive and utilize as useful information about the sound characteristics of the external environment. Test your basic knowledge of auditory physiology by taking this simple quiz.

(1) The cochlea is a hollow, spiral shaped part of the mastoid bone within the temporal bone of the skull. Cochlea is singular, while __________ is plural.

(2) Otoacoustic emissions (OAE) are sounds that arise from the __________, and can be recorded by placing a small microphone in the external auditory meatus (ear canal).

	(A) movements of the tympanic membrane (eardrum)
	(B) ossicles of the middle ear
	(C) cochlea within the inner ear

(3) The human brain perceives the intensity (i.e., loudness) of sound waves:

	(A) by detecting the frequency of action potentials arriving at the auditory cortex; with higher frequencies of action potentials correlating with higher intensity sounds.
	(B) by detecting the frequency of action potentials arriving at the auditory cortex; with higher frequencies of action potentials correlating with lower intensity sounds.
	(C) by detecting the specific location along the organ of Corti stimulated by sound, leading to the generation of action potentials that ultimately arrive at the auditory cortex. Higher intensity sounds evoke action potentials in auditory fibers stimulated by inner hair cells closer to the base of the cochlea, and lower intensity sounds evoke action potentials in auditory fibers stimulated by inner hair cells closer to the apex of the cochlea.
	(D) by detecting the specific location along the organ of Corti stimulated by sound, leading to the generation of action potentials that ultimately arrive at the auditory cortex. Higher intensity sounds evoke action potentials in auditory fibers stimulated by inner hair cells closer to the apex of the cochlea, and lower intensity sounds evoke action potentials in auditory fibers stimulated by inner hair cells closer to the base of the cochlea.

(4) The human brain perceives the frequency (i.e., pitch) of sound waves:

	(A) by detecting the frequency of action potentials arriving at the auditory cortex; with higher frequencies of action potentials correlating with higher frequency sounds.
	(B) by detecting the frequency of action potentials arriving at the auditory cortex; with higher frequencies of action potentials correlating with lower frequency sounds.
	(C) by detecting the specific location along the organ of Corti stimulated by sound, leading to the generation of action potentials that ultimately arrive at the auditory cortex. Higher frequency sounds evoke action potentials in auditory fibers stimulated by inner hair cells closer to the base of the cochlea, and lower frequency sounds evoke action potentials in auditory fibers stimulated by inner hair cells closer to the apex of the cochlea.
	(D) by detecting the specific location along the organ of Corti stimulated by sound, leading to the generation of action potentials that ultimately arrive at the auditory cortex. Higher frequency sounds evoke action potentials in auditory fibers stimulated by inner hair cells closer to the apex of the cochlea, and lower frequency sounds evoke action potentials in auditory fibers stimulated by inner hair cells closer to the base of the cochlea.

(5) In general, sensory fibers of the auditory nerve only innervate the inner hair cells and not the outer hair cells. However, the normal function of the outer hair cells, which happen to be approximately three times as numerous as the inner hair cells, is essential for normal hearing.

	True
	False

(6) Otoacoustic emissions (OAE) result from mechanical movements of these cells within the sensory epithelium of the organ of Corti.

	(A) Inner hair cells
	(B) Outer hair cells
	(C) Both inner hair cells and outer hair cells