What is “sound”?
A repetitive pattern of local increases and decreases in air pressure.
What is the approximate range of human hearing?
20 to 2000 Hz.
How are the physical properties of frequency and amplitude perceived?
Frequency is pitch and Amplitude is volume.
What are the structures of the outer ear and what role do they play in audition?
Pinna: collects and amplifies sound waves
Auditory canal: Tube leading from the pinna to the tympanic membrane.
What are the structures of the middle ear, and what role do they play in audition?
Ear Drum: Vibrates at the same frequency as the sound waves.
Ossicles: that transmit vibration across the middle ear.
Oval Window: opening from the middle ear to the inner ear.
What are the structures of the inner ear, and what role do they play in audition?
Cochlea: contains the primary receptor cells for hearing.
What are the receptor cells that detect sound waves, and how do they respond?
Hair cells respond by opening their ion channels and letting in potassium and calcium and releasing a neurotransmitter.
What cells provide inputs to the auditory nerve?
Inner hair cells and outer hair cells.
Where does the auditory nerve synapse?
Cochlear Nuclei.
Where is the primary auditory cortex (A1) located?
Temporal Lobe.
How is the primary auditory cortex organized?
Tonotopic Organization; Low to high frequency.
What are the strategies that we use to localize sounds?
Intensity differences (Loudness) and Latency Differences (Time)
