!Auditory System
!!Anatomical and functional overview
The auditory system is the sensory system for the sense of hearing. It includes both the sensory organs (the __ears__) and the auditory parts of the ((Sensory - System Overview|sensory system)).
The __outer ear__ is the external portion of the ear, which consists of the auricle (the folds of ((Musculoskeletal - Cartilage|cartilage)) surrounding the ear canal are called pinna) and the external ear canal covered in skin (epidermis and dermis). It gathers and reflects sound energy and focuses it on the eardrum. When reaching the the ((Sensory - Ear Middle - Ossicles, muscles and cartilage|tympanic cavity)), the sound waves have been amplified 30- to 100-fold in the range of frequencies from 3 to 12 kHz, which makes humans especially sensitive to these frequencies.
The eardrum separates the outer from the __middle ear__. In the air-filled tympanic cavity, a series of ((Sensory - Ear Middle - Ossicles, muscles and cartilage|ossicles)) transfer and convert the sound to higher pressure. The stapedius muscle is by reflex activated to protect the inner ear, reducing the transmission of sound energy.The ((Sensory - Ears - Eustachian Tube|Eustachian tube)) connects the ear to the ((Respiratory - Nasopharyngeal Mucosa |nasopharynx)).
While the middle ear still contains the sound information in wave form; it is converted to nerve impulses in the ((Sensory - Ear Inner - Hearing |cochlea)) of the __inner ear__. The electrochemical impulses are then passed on to the brain via the auditory nerve.
The inner ear also contains the ((Sensory - Ear Inner - Vestibular System|vestibular system)) which works together with the ((Sensory - Eyes Overview|visual system)) to keep objects in focus when the head is moving, thus creating the perception of balance necessary for coordination.
The __auditory nerve__ leads the sound information on to be processed in the brainstem,  the midbrain, and the thalamus, from where it is relayed to the temporal lobe in the cerebral cortex (temporal lobe, Wernicke-speech centre).

{img fileId="51" thumb="y" rel="box[g]"}

!!Brain
{img fileId="192" thumb="box"} Auditory cortex

!!!Relays
{img fileId="191" thumb="box"} Hearing Relays in brain stem and cortex
*Nuclei of the acoustic nerve: __Brain Stem__ lateral left & right at the junction of pons & cerebellum, brain-organ relation uncrossed 
*__Cerebral Cortex__: relay of the cochlea in baso-temporal postsensory area, caudal (below) the insula. Accordingly, territorial conflicts usually are maintained by auditory triggers (pitch & rhythm of voice). Brain-organ-relation crossed over.

!!!META-Organ Tissues
*((Sensory - Ears - Outer Ear Skin|Outer Ear Skin)) 
*Middle Ear - ((Sensory - Ears - Eustachian Tube|Tympanic Cavity and Eustachian Tube)) (BS +/-): "Auditory Chunk" or "prey-hearing": the need to get or get rid of auditory information
*Middle Ear - ((Sensory - Ear Middle - Ossicles, muscles and cartilage|Ossicles & Muscles)) (CM -/+): Sound management
*Inner Ear - ((Sensory - Ear Inner - Hearing |Cochlea - Hearing)) (CC -/+): Speech recognition and sound evaluation
*Inner Ear - ((Sensory - Ear Inner - Vestibular System|Vestibular System)) (CC -/+): Equilibrium, control (fear to fall)
