Comprehensive Guide to Cochlear Function, Hair Cells, and Synesthesia in Auditory Processing

What is the cochlea?

A spiral structure of the inner ear that contains the organ of Corti, which transduces vibrations into neural signals.

How long is the cochlea when unrolled?

About 35 mm long.

What are the three parallel channels in the cochlea filled with?

Watery fluids.

What is the function of the organ of Corti?

It translates movements of the cochlear partition into neural signals.

What are hair cells in the cochlea responsible for?

Transducing mechanical movements into neural activity sent to the brain.

What are the two types of hair cells in the cochlea?

Inner hair cells and outer hair cells.

What is the role of inner hair cells?

They convey almost all information about sound waves to the brain.

What do outer hair cells do?

They convey information from the brain and are involved in an elaborate feedback system.

What is the tectorial membrane?

A gelatinous structure that extends into the middle canal of the ear, causing the release of neurotransmitters when displaced.

What are stereocilia?

Hairlike extensions on the tips of hair cells that initiate the release of neurotransmitters when flexed.

What is synesthesia?

A phenomenon where stimulation of one sensory system evokes sensations in another system, such as sounds evoking colors.

What is color-graphonic synesthesia?

A type of synesthesia where individual letters and numbers evoke distinctive colors.

What is spatial-sequence synesthesia?

A type of synesthesia where individual elements in a sequence have corresponding locations in 3-D space.

What is sound-color synesthesia?

A type of synesthesia where certain sounds evoke visual images of corresponding colors.

What is the neurological hypothesis for synesthesia?

It may result from unusual connectivity between sensory cortices or abnormal connections forming during development.

What is the place code in the cochlea?

A coding mechanism where different parts of the cochlea are tuned to different frequencies based on mechanical displacement.

What is the temporal code for sound frequency?

A coding mechanism where frequency information is encoded by the timing of neural firing related to the sound wave's period.

What is the volley principle?

An idea stating that multiple neurons can provide a temporal code for frequency by firing at distinct points of a sound wave.

What happens if the vibration in the cochlea is very strong?

It continues through the helicotrema and back down the cochlea's tympanic canal, dissipating pressure at the round window.