Human hearing range
15-20,000 hertz
Anatomy of the ear
auricle
fleash and cartilage attached to each side of the head
-collects and focuses sound waves
-location
outer ear
Anatomy of the ear
tympanic membrane (ear drum)
separates outer and middle ear
- vibrates to sound waves
- vibrations passed to ossicles
outer ear
Anatomy of the ear
auditory ossicles (malleus, incus, & stapes)
amplify sound waves
middle ear
Anatomy of the ear
oval window
membrane in the inner ear
-transmits waves through the viscous fluid of the inner ear
middle ear
Anatomy of the ear
cochlea
snail shaped structure called the cochlea
-containes three fluid-filled tunnels
inner ear
Anatomy of the ear
organ of corti
hair cells (site of transduction
- auditory receptors
- mounted on two membranes
tectorial membrane
basilar membrane
inner ear
Anatomy of the ear
auditory nerve
movement of hair cells generates action potential along the auditory nerve
inner ear
Auditory Pathways in the Brain
Pathway from the inner ear to brain
- hair cells synapse on neurons
- axons enter hindbrain
- inferior colliculi (tectum)
- medial geniculate nucleus (thalamus)
- ascend to the primary auditory cortex
Auditory Pathways in the Brain
Auditory cortex
-primary cortex recieves input from medial geniculate nucleus
-secondary cortex responds best to complex tones
Auditory Pathways in the Brain
Parts of the auditory cortex
anterior auditory pathway -identifies sound “what”
posterior auditory pathway - identifies where the sound is
Auditory System
sound localization
comparison of responses from the two ears
3 cues: sound shadow, time of arrival, phase difference
