1. Anatomy and physiology of the ear

2. External ear Pinna (auricle) & External auditory meatus Pinna (auricle) & External auditory meatus Function: Localization Function: Localization

3. Middle ear Tympanic membrane, middle ear cavity, & ossicles (malleus, incus, stapes) Tympanic membrane, middle ear cavity, & ossicles (malleus, incus, stapes) Function: Compensating for impedance mismatch between air and fluid Function: Compensating for impedance mismatch between air and fluid

4. Three main components of middle ear transfer function 1. Area difference between tympanic membrane and stapes footplate 2. Ossicular level action 3. Buckling movement of tympanic membrane

5. Inner ear Bony and membraneous labyrinth Bony and membraneous labyrinth Vestibular system (Semicircular canals & Vestibule) Vestibular system (Semicircular canals & Vestibule) Auditory system (Cochlea) Auditory system (Cochlea)

6. Macrostructure of cochlea

7. Microstructure of cochlea

8. Function of cochlea Frequency analysis of incoming sound: Basilar membrane acts as a series of bandpass filters Frequency analysis of incoming sound: Basilar membrane acts as a series of bandpass filters Transduction of mechanical vibration to electrochemical/neural impulses: Forward transduction Transduction of mechanical vibration to electrochemical/neural impulses: Forward transduction Outer hair cells: Responsible for cochlear amplifier (Backward transduction) Outer hair cells: Responsible for cochlear amplifier (Backward transduction)

9. Pathways of sound Air conduction (AC): Transmission through outer, middle, inner ear, and higher up. Air conduction (AC): Transmission through outer, middle, inner ear, and higher up. Bone conduction (BC): Transmission that stimulates the inner ear directly through mechanical vibration of the skull. Bone conduction (BC): Transmission that stimulates the inner ear directly through mechanical vibration of the skull.

10. Normal hearing Conductive hearing loss Sensorineural hearing loss Mixed hearing loss Outer earMiddle earInner earAuditory nerveOuter earMiddle earInner earAuditory nerveOuter earMiddle earInner earAuditory nerveOuter earMiddle earInner earAuditory nerve CONDUCTIVE SENSORINEURAL