Editing Place theory (section)

{{Short description|Theory about mechanism of hearing}}
'''Place theory''' is a [[theory]] of [[hearing (sense)|hearing]] that states that our perception of sound depends on where each component [[frequency]] produces [[vibrations]] along the [[basilar membrane]].  By this theory, the [[pitch (psychophysics)|pitch]] of a sound, such as a human voice or a musical tone, is determined by the places where the membrane vibrates, based on frequencies corresponding to the [[tonotopic]] organization of the primary auditory neurons.<ref name="mather">{{cite book |author=Mather |first=George |url=https://books.google.com/books?id=oUNfSjS11ggC&dq=pitch+%22place+theory%22&pg=PA123 |title=Foundations of perception |publisher=Psychology Press |year=2006 |isbn=0-86377-834-8}}</ref><ref name="moore">{{cite book |author=Moore |first=Brian C. J. |url=https://books.google.com/books?id=tkbOivKH2HkC&dq=pitch+%22temporal+theory%22+places+tonotopic+%22place+theory%22+alternative&pg=PA196 |title=An introduction to the psychology of hearing |publisher=Emeraldn Group Publishing |year=2003 |isbn=0-12-505628-1}}</ref>

More generally, schemes that base attributes of auditory perception on the neural firing rate as a function of place are known as '''rate–place schemes'''.<ref>{{cite book |author=Delgutte |first=Bertrand |title=The Handbook of Phonetic Sciences |publisher=Blackwell Publishing |year=1999 |isbn=0-631-21478-X |editor1=William J. Hardcastle |chapter=Auditory Neural Processing of Speech |editor2=John Laver |chapter-url=https://books.google.com/books?id=VrMEG-lKcaEC&dq=rate+place+theory+hearing+spectrum&pg=PA515}}</ref>

The main alternative to the place theory is the [[temporal theory]],<ref name=moore/> also known as timing theory.<ref name=mather/>  These theories are closely linked with the volley principle or [[volley theory]],<ref name="gelfand">{{cite book |author=Gelfand |first=Stanley A. |url=https://books.google.com/books?id=UqXS8CLJML4C&dq=%22temporal+theory%22+%22volley+theory%22&pg=PA72 |title=Essentials of Audiology |publisher=Thieme |year=2001 |isbn=1-58890-017-7}}</ref> a mechanism by which groups of neurons can encode the timing of a sound waveform.  In all cases, [[neural firing]] patterns in time determine the perception of pitch.  The combination known as the '''place–volley theory''' uses both mechanisms in combination, primarily coding low pitches by [[temporal pattern]] and high pitches by rate–place patterns.<ref name=gelfand/>  It is now generally believed that there is good evidence for both mechanisms.<ref>{{cite book |author=d'Cheveigné |first=Alain |title=Pitch |publisher=Birkhäuser |year=2005 |isbn=0-387-23472-1 |editor1=Christopher J. Plack |chapter=Pitch Perception Models |editor2=Andrew J. Oxenham |editor3=Richard R. Fay |editor4=Arthur N. Popper |chapter-url=https://books.google.com/books?id=n6VdlK3AQykC&dq=place+pitch++volley+theory++believed&pg=PT214}}</ref>

The place theory is usually attributed to [[Hermann Helmholtz]], though it was widely believed much earlier.<ref>{{cite book |author=Lightfoot Barnes |first=Charles |url=https://books.google.com/books?id=6TQIAAAAIAAJ&dq=cochlea+Corti+Helmholtz+intitle:acoustics&pg=PA160 |title=Practical Acoustics |publisher=Macmillan |year=1897 |pages=160}}</ref><ref>{{cite book |author=Martin |first=Benjamin |url=https://books.google.com/books?id=UHgKAAAAIAAJ&dq=Corti+cochlea+%22experienced%22+intitle:philosophy+inauthor:benjamin+inauthor:martin&pg=PA415 |title=The Young Gentleman and Lady's Philosophy: In a Continued Survey of the Works of Nature and Art by Way of Dialogue |publisher=W. Owen |year=1781}}</ref>

Experiments to distinguish between place theory and rate theory are difficult to devise, because of the strong correlation: large vibrations with low rate are produced at the apical end of the basilar membrane while large vibrations with high rate are produced at the basal end. The two can be controlled independently using [[cochlear implant]]s: pulses with a range of rates can be applied via electrodes distributed along the membrane. Experiments using implant recipients showed that, at low stimulation rates, ratings of pitch on a pitch scale were proportional to the log of stimulation rate, but also decreased with distance from the round window. At higher rates, the effect of rate was weaker, but the effect of place was strong.<ref>{{cite journal |vauthors=Fearn R, Carter P, Wolfe J |title=The perception of pitch by users of cochlear implants: possible significance for rate and place theories of pitch |journal=Acoustics Australia |volume=27 |issue=2 |pages=41–43 |year=1999 | url=http://www.phys.unsw.edu.au/jw/Fearnetal.html}}</ref>