Sound (Audition) 1. 2. 3. 4. 5. Auditory Structure - Part 1: Pressurized sound waves are how sound is transmitted, through areas of low and of high pressure Soundwaves of lower frequencies travel further in the ear than those of high frequencies Your ear is able to break apart summated frequencies because they travel different lengths in the ear depending on its frequency Anatomy of the ear: Pinna (Auricle) is the visible portion of the ear and functions to funnel sound waves into the ear canal, where the sound is amplified External Auditory Meatus (Auditory Canal) is the outermost canal responsible for propagating sound to the tympanic membrane (eardrum) Sound is propagated from the eardrum through the malleus, incus, and stapes The stapes then causes the oval window (elliptical window) to vibrate back and forth, causing fluid in the cochlea to move and eventually cause the circular (round) window to vibrate Organ of corti is this membrane that allows the fluid to only go towards the round window and not back to the oval window The external ear is everything from the pinna → the eardrum The middle ear is everything from the malleus → stapes The inner ear is the cochlea Auditory Processing: The ear can hear frequencies from 20 - 20,000 Hz Hair cells at the beginning of the cochlea are stimulated by high frequency sounds while hair cells at the end/apex of the cochlea are stimulated by low frequency sounds Cochlear Implants: Cochlear implants are useful for individuals with sensorineural hearing loss (“nerve deafness”), which basically means that the hair cells don’t convert the incoming signal into an electrical impulse