cgs 2301 - audition

functions of sound

• location

• identification

• efficiency

• vestibulation

location

carries info about where you and where things are

identification

identify someone by their voice

efficiency

travels fairly well in ear

vestibulation

sense of balance

human hearing threshold range

20 to 20,000 Hz

sine wave

displacement, amplitude, period, time

frequency

• also known as pitch

• high/low pitch

• measured in cycles/sec or Hertz

amplitude

• loudness

• height of sound wave

• higher → louder

phase

how far a wave is in its current cycle

binaural cues

three major parts of the ear

• outer ear

• middle ear

• inner ear

outer ear

• collects sound waves

middle ears

• transmits vibrations

• contains ossicles (small bones)

inner ear

• semicircular canals

• cochlea

• auditory nerve to brain

• transduction

cochlea

fluid filled tube

basilar membrane

• low frequency at the tip

• high frequency at the back

hair cells

specialized auditory receptor neurons embedded in ))

ear to the brain

cochlear nucleus → superior olive (olivary nucleus) → inferior colliculus → medial geniculate thalamus → auditory cortex

[insert mnemonic]

auditory cortex

A1: topographic organization

dorsal

where am i hearing a certain sound

ventral

what am i hearing

semicircular canals

vestibulation

three fluid filled tubes located in inner ear

feedback + visual info = balance