Editing Phonetics (section)

=== Audition ===
{{hatnote|Main article: [[Hearing]]; for further information see [[Neuronal encoding of sound]]}}
[[File:Journey of Sound to the Brain.ogg|thumb|How sounds make their way from the source to the brain|300x300px]]
Audition, the process of hearing sounds, is the first stage of perceiving speech. Articulators cause systematic changes in air pressure which travel as sound waves to the listener's ear. The sound waves then hit the listener's [[ear drum]] causing it to vibrate. The vibration of the ear drum is transmitted by the [[ossicles]]—three small bones of the middle ear—to the [[cochlea]].{{sfn|Johnson|2003|p=46–7}} The cochlea is a spiral-shaped, fluid-filled tube divided lengthwise by the [[organ of Corti]] which contains the [[basilar membrane]]. The basilar membrane increases in thickness as it travels through the cochlea causing different frequencies to resonate at different locations. This [[tonotopic]] design allows for the ear to analyze sound in a manner similar to a [[Fourier transform]].{{sfn|Johnson|2003|p=47}}

The differential vibration of the basilar causes the [[hair cells]] within the organ of Corti to move. This causes [[depolarization]] of the hair cells and ultimately a conversion of the acoustic signal into a neuronal signal.{{sfn|Schacter|Gilbert|Wegner|2011|p=158–9}} While the hair cells do not produce [[action potential]]s themselves, they release neurotransmitter at synapses with the fibers of the [[auditory nerve]], which does produce action potentials. In this way, the patterns of oscillations on the basilar membrane are converted to [[spatiotemporal pattern]]s of firings which transmit information about the sound to the [[brainstem]].{{sfn|Yost|2003|p=130}}