Vider li fonte de «Son»

{{Bon articul|Son|22-im de septembre 2023}}
[[File:Thoth08BigasDrumEvansChalmette.jpg|thumb|upright=1.35|Un [[tambur]] fa son usant un vibrant [[membrane]]]]

In [[fisica]], '''son''' es un [[vibration]] que propaga quam un [[acustic unde]], per un [[transmissional medie]] quam un [[gas]], [[liquide]], o [[solide]].
In human [[fisiologie]] e [[psicologie]], son es li ''reception'' de tal undes e lor ''[[perception]]'' per li [[cerebre]].<ref>{{cite book |publisher=Western Electrical Company |title=Fundamentals of Telephone Communication Systems |date=1969 |page=2.1}}</ref> 
Sol sonic undes que have  [[frequentie|frequenties]] inter circa 20&nbsp;Hz e 20&nbsp;kHz, li range de [[audial frequentie]], educte un auditori percept in homes. In aere a atmosferic pression, tis representa sonic undes con [[longore de unde|longore]]s de 17 metres a 1.7 cm. Son undes super 20&nbsp;[[kHz]] es nominat [[ultrason]] e ne es audibil to homes. Sonic undes sub 20&nbsp;Hz es nominat [[infrason]]. Diferent species de animales have variant [[audial range]]s.

==Acustica==
[[Acustica]] es li interdisciplinari [[scientie]] que studia [[mecanic unde]]s in gases, liquides, e solides, includente [[vibration]], son, ultrason, e infrason. 

Aplications de acustica es trovat in presc omni areas de modern societé, subdisciplines include [[aeroacustica]], [[audial signale formation]], [[architectural acustica]], [[bioacustica]], electro-acustica, vicinal [[brue]], [[musical acustica]], [[bruic control]], [[psichoacustica]], [[parlada]], [[ultrason]],  [[subaquatic acustica]], e [[vibration]].<ref>{{Cite web |last=Acoustical Society of America |title=PACS 2010 Regular Edition—Acoustics Appendix |url=http://www.aip.org/pacs/pacs2010/individuals/pacs2010_regular_edition/reg_acoustics_appendix.htm |access-date=22 May 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130514111126/http://www.aip.org/pacs/pacs2010/individuals/pacs2010_regular_edition/reg_acoustics_appendix.htm |archive-date=14 May 2013 }}</ref>

==Definition==
Son es definat quam "(a) [[Oscillation]] in pression, tension, particulal deplazzement, particulal velocitá, etc., propagat in un medie con intern forties (p.ex., elastic o viscosi), o li superposition de tal propagat oscillation. (b) Auditori sensationes evocat per li oscillation descrit in (a)."<ref>[[ANSI/ASA S1.1-2013]]</ref> 
Son posse esser videt quam un undic motion in  aere o altri elastic medies. In ti casu, son es un stimul. Son anc posse esser videt como un excitation del audial mecanisme que resulta in li perception de son. In ti casu, son es un [[sensu|sensation]].

==Fisica==
Son posse propagar tra un medie quam aere, aqua, e solides quam [[longitudinal unde]]s e anc quam un [[transversal unde]] in un [[solide]]. Li sonic undes es generat per un sonic fonte, quam li vibrant [[Diafragma (acustica)|diafragma]] de un electronic parlator. Li sonic font crea vibrationes in li circumdant medie. Durante que li fonte continua vibrar li medie, li vibrationes propaga ex li fonte al [[rapiditá de son]], talmen formar li sonic unde. A un regulat distantie fro li fonte, li [[pressio]], [[velocitá]], e deplazzement del medie varia per témpor. A un instante de témpor, li pression, velocitá, e deplazzement varia in spacie. Nota que li particules del medie ne propaga con li sonic unde. Durante propagation, undes posse esser [[Reflection (fisica)|reflectet]], [[Refraction|refractet]], o [[Atenuation|atenuat]] per li medie.<ref name="JHU">{{Cite web |url=http://pages.jh.edu/~virtlab/ray/acoustic.htm |title=li Propagation of sound |access-date=26 June 2015 |url-status=live |archive-url=https://web.archive.org/web/20150430054640/http://pages.jh.edu/~virtlab/ray/acoustic.htm |archive-date=30 April 2015 }}</ref>

Sonic propagation es afectet generalmen per tri conditiones:
* Un complex relation inter li [[densitá]] e pression del medie. Ti relation, afectet per temperatura, determina li rapiditá de son intra li medie.
* Motion del medie self. Si li medie es movent, ti movement mey cresce o decresce li absolut rapiditá del sonic unde, dependent sur li direction del movement. Por exemple, son movent tra vente va haver su rapiditá de propagation cresce per li ventic rapiditá si li son e vente move in li sam direction. Si li son e vente move in contrari directiones, li rapiditá del sonic unde va decrescer per li rapiditá del vente.
* Li viscositá del medie. Li [[viscositá]] determina li rate a quel li son es atenuat. Por multi medies, quam aere o aqua, atenuation causat per viscositá es negligibil.
Quande son move tra un medie que ne have constant fisic proprietas, it posse esser refractet (o disperset o focat).<ref name="JHU" />

Li mecanic vibrationes que posse esser interpretat quam son posse propaga tra omni [[Statu de materie|formes de materie]]: gases, liquides, solides, e [[plasma (fisica)|plasmas]]. Li materie que suporta li son es nominat li [[Transmission medie|medie]]. Son ne posse propaga tra un [[vacuo]].<ref>[http://www.qrg.northwestern.edu/projects/vss/docs/space-environment/1-es-there-son-in-space.html is there sound in space?] {{webarchive|url=https://web.archive.org/web/20171016010300/http://www.qrg.northwestern.edu/projects/vss/docs/space-environment/1-is-there-sound-in-space.html |date=2017-10-16 }} Northwestern University.</ref><ref>[http://curious.astro.cornell.edu/about-us/150-people-in-astronomy/space-exploration-e-astronauts/general-questions/918-can-you-hear-sounds-in-space-beginner can you hear sounds in space? (Beginner)] {{webarchive|url=https://web.archive.org/web/20170618062312/http://curious.astro.cornell.edu/about-us/150-people-in-astronomy/space-exploration-e-astronauts/general-questions/918-can-you-hear-sounds-in-space-beginner |date=2017-06-18 }}. Cornell University.</ref>

===Undes===
Son es transmisset per gases, plasma, e liquides quam [[longitudinal unde]]s, anc nominat [[compression (fisic)|compressional]] undes. It besona un medie por propagar. In solides, tamen, son posse be transmisset quam ambi longitudinal undes e [[transversal unde]]s. Longitudinal son undes es undes of alternant deviationes de [[pression]] del [[Mecanic equilibrie|equilibrial]] pression, que causa local regiones de [[compression (physical)|compression]] e [[rarefaction]], ma [[transversal unde]]s (in solides) es undes de alternant [[tension tondemental]] a un rect angul al direction de propagation.

Son undes mey esser videt con parabolic spegules e objectes que fa son.<ref>{{Cite web |title=What Does Sound Look Like? |url=https://www.youtube.com/watch?v=px3oVGXr4mo |work=NPR |publisher=YouTube |access-date=9 April 2014 |url-status=live |archive-url=https://web.archive.org/web/20140410064648/http://www.youtube.com/watch?v=px3oVGXr4mo |archive-date=10 April 2014 }}</ref>

Li energie portat per un sonic unde oscilla inter li potential energie del extra [[compression (physical)|compression]] (in li casu de longitudinal undes) o lateral deplazzement [[deformation axial]] (in li casu de transversal undes) del materie, e li kinetic energie del deplazzemental velocita del particules del medie.

[[File:The Elements of Sound jpg.jpg|thumb|Un 'pression sur témpor' graf de a 20 ms registration del ton de un [[clarinette]] demonstra li du fundamental elementes de son: pression e témpor.]]
[[File:Sine waves different frequencies.svg|thumb|Sones posse esser representat quam un mixtura de lor component [[Sinal unde|Sinusoidal undes]] de diferent frequenties. Li fundic undes have plu alt frequenties quam tis super. Li horizontal axe representa témpor.]]
Hay multi complexitas relatent al transmission de sones, al punctu de reception (p.ex., li oreles), son posse esser divider ad-in du simplic elementes: pression e témpor. Ti fundamental elementes forma li base de omni sonic undes. Ili posse esser usat de descrir, in absolut términos, omni sones noi audi.

Sonic [[unde]]s sovente es simplificat a un descrition in términos de [[Sinal unde|sinusoidal]], [[planal unces]]s, que es caracterisat per ti generic proprietas:
* [[Frequentie]], o su inversi, [[longore de unde]]
* [[Amplore]], [[sonic pression]], o [[Sonic intensitá|intensitá]]
* [[Rapiditá de son]]
* [[Direction (geometrie, geografie)|Direction]]

Son que es perceptibil per homes have frequenties de circa 20&nbsp;Hz a 20,000&nbsp;Hz. In aere a [[standard temperatura e pression]], li corespondent longores de son undes rangea de 17 metres a 17 millimetres. Quelcvez rapiditá e direction es combinat as un [[velocitá]]; undic numere e direction es combinat quam un [[undic vectore]].

[[Transversal undes]]s have li additional proprietá, ''[[Polarisation (undes)|polarisation]]'', e ne es un trate de sonic undes.

===Rapiditá===
[[File:FA-18 Hornet breaking sound barrier (7 July 1999) - filtered.jpg|right|thumb|U.S. Flotte [[F/A-18 Hornet|F/A-18]] aproxima se li rapiditá de son. Li blanc nimbe es format per condensat guttetas de aqua causat per un cade in li pression circum li aeroplane.<ref name=nasa>{{Cite APOD |title=A Sonic Boom|access-date=26 June 2015 |date=19 August 2007}}</ref>]]

Li rapiditá de son depende sur li medie tra quel undes propaga, e it es un fundamental proprietá del materiale. 
Li prim significant eforti del mesuration del rapiditá de son esset fat per [[Isaac Newton]]. Il credet li rapiditá de son in un particulari substantie es egal al radica quadratic del pression actent sur it dividet per su densitá:

: <math>c = \sqrt{\frac{p}{\rho}}.</math>

To esset monstrat esser incorect subsequentmen, e li francesi matematico [[Pierre-Simon Laplace|Laplace]] corectet li formul per deducte que li fenomeno de sonic propagation ne es  isotermal, quam Newton pensat, ma [[Transformation adiabatic|adiabatic]].  Il addit altri factore al equation — [[proportion de capacitá termic|''gamma'']]—e multiplica
<math>\sqrt{\gamma}</math>
per
<math>\sqrt{p/\rho}</math>,
talmen obtener li equation:
<math>c = \sqrt{\gamma \cdot p/\rho}</math>.
Pro que
<math>K = \gamma \cdot p</math>,
li final equation deveni
<math>c = \sqrt{K/\rho}</math>,
quel anc es savet quam li Newton–Laplace equation. In ti equation, ''K'' es li elastic module de compressibilitá, ''c'' es li rapiditá de son, e <math>\rho</math> es li densitá.  Talmen, li rapiditá de son es proportational al [[radica quadratic]] del [[module de compressibilitá]] del medie dividet per su densitá.

Ti proprietas fisic e li rapiditá de son changea con circumdant conditiones. Por exemple, li rapiditá de son in gases depende sur temperatura. In 20 C aere al nivelle del mare, li rapiditá de son es proxim 343 m/s. In plu densi substanties, rapiditá es anc plu grand. In dulci aqua, li rapiditá de son es circa 1482 m/s, ma in [[stal]], it es 5960 m/s.

===Nivelle de sonic pression===
''[[Sonic pression]]'' es li diferentie, in un dat medie, inter li medial local pression e li pression in li sonic unde. 
Un quadrat de ti diferentie es usualmen mediat sur témpor e/o spacie, e un radica quadratic de to da un [[medio quadratic]]. 
Pro que li human orel posse detecter sones de un larg range de amplores, sonic pression sovente es mesurat quam un nivelle sur un logaritmic scale de [[decibel]]es. Li ''nivelle de sonic pression'' (SPL) or ''L''<sub>p</sub> es definit quam
:<math>
L_\mathrm{p}=10\, \log_{10}\left(\frac{{p}^2}{{p_\mathrm{ref}}^2}\right) =20\, \log_{10}\left(\frac{p}{p_\mathrm{ref}}\right)\mbox{ dB}\,
</math>

:u ''p'' es li [[medio quadratic]] del sonic pression e <math>p_\mathrm{ref}</math> es un ''[[referential sonic pression]]''. 
Comunmen usat referential son pressiones, definit in li standard [[American National Standards Institute|ANSI]] [[ANSI S1.1-1994|S1.1-1994]], es 20 [[micropascal|µPa]] in aere e 1 [[micropascal|µPa]] in aqua. Sin un specificat referentie de sonic pression, un valore expresset in decibeles ne posse representar un nivelle de sonic pression.

Pro que li human orel ne have un constant [[Responsivitá|spectral response]], sonic pressiones sovente es scalat per [[frequentie]] por que li mesurat nivelle egala li nivelles perceptet plu proximen. Li [[International Electrotechnic Commission]] (IEC) ha definit pluri schemas de scalante.

==Perception==
Un distint usu del termino ''son'' de su usu in fisica es que de fisiologie e psichologie, u ''son'' refere al perception per li cerebre. Li campe de [[psichoacustica]] es dedicat a tal studies. 

Li fisic reception de son in un audint organisme es limitat a un range de frequenties. Homes normalmen audi sonic frequenties inter circa 20&nbsp;[[Hertz|Hz]] e 20,000&nbsp;Hz (20&nbsp;[[kHz]]), e li plu alt limite decresce con age.<ref name="Olson1967">{{Cite book |url=https://archive.org/details/musicphysicsengi0000olso |url-access=registration |title=Music, Physics and Engineering |publisher=Dover Publications |isbn=9780486217697 |last1=Olson |first1=Harry F. Autor |date=1967 |page=[https://archive.org/details/musicphysicsengi0000olso/page/249 249]}}</ref>{{rp|249}} 
Quelcvez ''son'' significa solmen ti vibrationes con [[frequenties]] que es intra li [[audial range]] por homes<ref>{{cite journal |title=li American Heritage Dictionary of the English Language |edition= Fourth |publisher=Houghton Mifflin Company |date=2000 |url=http://www.bartleby.com/61/65/S0576500.html |archive-url=https://web.archive.org/web/20080625012016/http://www.bartleby.com/61/65/S0576500.html |archive-date=June 25, 2008 |access-date=May 20, 2010}}</ref> o it mey relater a un particulari animale. Altri species have diferent audial ranges. Por exemple, canes posse percepter vibrationes plu alt quam 20&nbsp;kHz. 

Quam un signale perceptet per un del majori [[sensu]]s, son es usat per multi species por [[defensiv mecanisme (biologie)|detecter dangere]], [[navigation]], [[predation]], e comunication.

[[Brue]] es un termino sovente usat de significa un indesirat son. In scientie e tecnologie, brue es un indesirat componente que obscura li desirat signale. Tamen, in sonic perception, brue sovente posse esser usat de identicar li fonte of un son e es un important componente del perception de timbre.

Hay, historicmen, six experimentalmen separabil medies per quel sonic undes es analisat. Ili es:  [[Altesse (musica)|altesse]], [[Duration (musica)|duration]], [[Fortesse (acustica)|fortesse]], [[Timbre (musica)|timbre]], [[Textura (musica)|sonic textura]], e [[sonic localisation|spatial location]].<ref>Burton, R.L. (2015). [https://search.informit.com.au/documentSummary;dn=649996699786780;res=IELHSS the elements of music: what are they, and who cares?] {{Webarchive|url=https://web.archive.org/web/20200510200056/https://search.informit.com.au/documentSummary;dn=649996699786780;res=IELHSS |date=2020-05-10 }} In J. Rosevear & S. Harding. (Eds.), ASME XXth National Conference proceedings. Paper presented at: Music: Educating for life: ASME XXth National Conference (pp. 22–28), Parkville, Victoria: li Australian Society for Music Education Inc.</ref> Alcun de ti terminos have un definition standardisat (p.ex., in li ANSI Acustical Terminologie [[ANSI/ASA S1.1-2013]]).

===Altesse===
[[File:Pitch perception.png|thumb|Figura 1. Perception de altesse]]

[[Altesse (musica)|altesse]] es perceptet quam lu "bass" o "alt" de un son es e representa li ciclic, repetitiv natura del vibrationes que composi son. 
Por simplic sones, altesse es relat al frequentie del plu lenti vibration in li son (nominat li fundamental harmonic). 
In li casu de complex sones, perception de altess posse variar. Quelcvez individuales identica diferent altesses por li sam son, basat sur lor personal experientie de particulari sonic arangeamentes. Selection de un particulari altesse es determinat per pre-conscient examination de vibrationes, includent lor frequenties e li equilibrie inter les.  
Omni son es plazzat sur un continuo de altesse de bass a alt. Figura 1 monstra un exemple de reconossion de altesse. Durante li audition, chascun son es analisat por un arangeament repetint  e li resultes es misset al auditori cortex quam un singul altesse de un certe altore (octave) e croma (nómine del note).

===Duration===
[[File:Duration perception.png|thumb|Figura 2. Perception de duration]]
[[Duration (musica)|Duration]] es perceptat quam lu "long" o "brevi" de un son es e
relate al signales de comense e finale fat per nerval responses al sones. Li duration de un son usualmen dura del punctu in témpor li son prim es observet til li son es identificat quam havent changet o cessat.<ref>{{Cite journal |last1=Jones |first1=S. |last2=Longe |first2=O. |last3=Pato |first3=M.V. |year=1998 |title=Auditory evoked potentials to abrupt pitch and timbre change of complex tones: electrophysiological evidence of streaming? |journal=Electroencephalography and Clinical Neurophysiology |volume=108 |issue=2 |pages=131–142 |doi=10.1016/s0168-5597(97)00077-4|pmid=9566626 }}</ref> Quelcvez to ne es directmen relat al fisic duration de a son. 

===Fortesse===
[[File:Loudness perception v5.gif|thumb|Figura 3. Perception de fortesse]]
[[Fortesse (acustica)|Fortesse]] es perceptet quam qualmen "fort" or "piani" un son es e relate al tot númere de stimulationes del auditori nerve sur brevi ciclic témporal periodes. 
Por brevi durationes, un tre brevi son posse semblar plu piani quam un plu long son, benque ili have li sam nivelle de intensitá. Préter circa 200 ms, to ne es li casu, e li duration del son ne afecte li aparent fortesse del son. Figure 3 da un impression de qualmen fortessal information es addit sur un periode de circa 200 ms ante it es misset al auditori cortice. 
Plu fort signales fa un plu grand 'pussation' sur li membrane basilari e dunc stimula plu mult nerves, quel causa un plu vigorosi signale de fortesse. 

===Timbre===
[[File:Timbre perception.png|thumb|Figura 4. Perception de timbre]]
[[Timbre (musica)|Timbre]] es perceptet quam li qualitá de diferent sones (p.ex., li ton de un musical instrument o li qualitá de un voce) e representa li pre-conscient distribution de un sonic identitá a un son (p.ex. “vi un hobóe!"). Ti identitá es basat sur information ganiat ex frequential transientes, bruesse, inconstantie, perceptet altesse, e li extension e intensitá del supertones in li son sur un témporal intervalle.
Li maniere in quel un son changea in témpor (vide Figura 4) provide lu max del information por identification de timbre. Mem si un curt section del undal forme de chascun instrument apara tre simil, li diferenties de changes in témpor inter li clarinette e li piano es evident in ambi fortesse e harmonic contenete. Minu aparent es li diferent brues audit, quam aeral sibilationes por li clarinette e martellic colpes por li piano.

===Textura===
[[Textura (musica)|Sonic textura]] relate al númere de fontes de son e li interaction inter les.<ref>{{Cite |author1=Cohen, D. |author2=Dubnov, S. |date=1997 |title=Gestalt phenomena in musical texture |journal=Journal of New Music Research |volume=26 |issue=4 |pages=277–314 |url=https://www.researchgate.net/publication/233076257 |access-date=2015-11-19 |url-status=live |archive-url=https://web.archive.org/web/20151121084708/http://www.researchgate.net/profile/Shlomo_Dubnov/publication/233076257_Polyspectra_as_measures_of_sound_texture_and_timbre*/links/0f31752f6ce3c49334000000.pdf |archive-date=2015-11-21 |doi=10.1080/09298219708570732 }}</ref><ref>Kamien, R. (1980). Music: an appreciation. New York: McGraw-Hill. p. 62</ref> 
Li parol ''textura'', in ti contextu, relate al separation cognitiv de objectes auditori.<ref name="Cariani, P. 2012 pp. 351-390">{{Cite book | doi=10.1007/978-1-4614-2314-0_13| chapter=Toward a Theory of Information Processing in Auditory Cortex| title=li Human Auditory Cortex| volume=43| pages=351–390| series=Springer Handbook of Auditory Research| year=2012| last1=Cariani| first1=Peter| last2=Micheyl| first2=Christophe| isbn=978-1-4614-2313-3}}</ref> In [[musica]], textura sovente refere al diferenties inter [[unison]], [[polifonie]], e [[homofonie]], ma it anc posse relate (por exemple) a un ocupat cafe; tal son forsan es un ''[[cacofonie]]''.

===Spacial location===
Spatial location representa li cognitiv position de un son in un vicinal contextu, includente ambi horizontalmen e verticalmen, e li distantie del sonic fonte e li trates del sonic vicinité.<ref name="Cariani, P. 2012 pp. 351-390"/><ref>Levitin, D.J. (1999). Memory for musical attributes. In P.R. Cook (Ed.), Music, cognition, and computerized sound: an introduction to psychoacoustics (pp. 105–127). Cambridge, Massachusetts: li MIT press.</ref>

==Ultrason==
[[File:Ultrasound range diagram.svg|thumb|upright=1.3|Aproximativ range de frequenties de ultrason.]]
[[Ultrason]] es sonic undes con frequenties plu alt quam 20.000&nbsp;Hz. Ultrason ne es diferent de audibil son in su fisic proprietas, ma it ne posse audit per homes.
Ultrasonic devises opera con frequenties de 20&nbsp;kHz til pluri gigahertz.

[[Medical ultrason]] comunmen es usat por diagnoses e terapie.

== Infrason ==
[[Infrason]] es sonic undes con frequenties plu bass quam 20&nbsp;Hz. Benque sones de tal bass frequentie es tro bass por homes de audir, balenes, elefantes, e alcun altri animales posse audir infrason e usa it de comunicar. It posse esser usat de detecter vulcanic eruptiones e es usat in alcun tipes de musica.<ref>{{Cite journal|last=Leventhall|first=Geoff|date=2007-01-01|title=What es infrasound?|journal=Progress in Biophysics e Molecular Biology|series=Effects of ultrasound and infrasound relevant to human health|volume=93|issue=1|pages=130–137|doi=10.1016/j.pbiomolbio.2006.07.006|pmid=16934315|issn=0079-6107|doi-access=free}}</ref>

==Vide anc==
* [[Musical instrument]]
* [[Sonic reproduction]]
* [[Acustic impedantie]]
* [[Phon]]
* [[Sone]]
* [[Nivelle de sonic intensitá]]
* [[Acustic teorie]]
* [[Musical ton]]
* [[Resonantie]]

==Referenties==
<references/>

[[Categorie:Son]]
[[Categorie:Audition]]
[[Categorie:Unde]]
[[Categorie:Acustica]]