Sound Flashcards
Frequency
khZ - determines pitch
Amplitude
Height of soundwave - determines volume
Complexity
Texture of soundwave - determines timbre
Human hearing range
20-20,000Hz
Human hearing range that is most sensitive
1,000-4,000 Hz
Pain treshold for volume
about 140dB
Pinna
Outer ear. The bit that sits outside the skull
Pinna
Outer ear. The bit that sits outside the skull
How big is the auditory canal?
3cm long, 0.6cm wide
Ear drum
Tympanic membrane. Boundary between inner and middle ears.
Three smallest bones found in human body
Collectively known as the ossicles. Consist of the malleus (hammer), incus (anvil) and stapes (stirrup), which hits the oval window
Middle ear is filled with
Air
Inner ear is filled with
fluid
Oval window
Hit by the stapes. Pressure goes in oval window, out of round window.
Three components of inner ear
Vestibule (entrance), Cochlea and Semicircular Canals
Three canals in Cochlea
Scala vestibuli; Scala Media and Scala Tympani
First part of cochlea to obtain acoustic input
Scala Vestibuli (flows back around through Scala Tympani and out of the round window)
The membrane in between the scala vestibuli and scala media
Basilar Membrane
What turns soundwaves into neural impulses?
The organ of corti
What turns soundwaves into neural impulses?
The organ of corti
Where on the basilar membrane are low and high frequency sounds detected?
Low sounds displace at the apex (wide end) where high sounds displace at the narrow end near the vestibule
Tectorial membrane
Located above the basilar membrane - it is the shelf against which the cilia move
Place theory
Information about different frequencies is coded by different locations on the basilar membrane
Frequency Theory
Information about different frequencies is detected by the firing rate of neurons in the auditory system
Auditory pathway
Ear Cochlear nucleus Superior Olive Inferior Colliculus Medial Geniculate Nucleus (in the Thalamus) Auditory Cortex (Temporal Lobe)
Auditory pathway
Ear Cochlear nucleus Superior Olive Inferior Colliculus Medial Geniculate Nucleus (in the Thalamus) Auditory Cortex (Temporal Lobe)
Localization of sound
Sound Shadow (loudest in one ear) Time of arrival (arrives in one ear quicker) Phase difference (out of phase)
Under resting conditions, cilia are connected via
Tip Links
Where is the first area in the brain to receive input from both ears?
The Superior Olive; helps to locate sound
Where is the Primary Auditory Cortex located?
Temporal Lobes
The Auditory Cortex is found in which Gyri?
Heschl’s Gyrus
