Formant 11024 218904031 2008-06-12T18:14:24Z AnnaFrance 7002667 [[WP:AWB/T|Typo fixing]], typos fixed: of of → of using [[Project:AutoWikiBrowser|AWB]] [[Image:Spectrogram -iua-.png|250px|thumb|[[Spectrogram]] of American English vowels {{IPA|[i, u, ɑ]}} showing the formants ''f''<sub>1</sub> and ''f''<sub>2</sub>]] A '''formant''' is a peak in the [[frequency spectrum]] of a sound caused by [[acoustic]] [[resonance]].<ref>Titze, I.R. (1994). Principles of Voice Production, Prentice Hall, ISBN 978-0137178933.</ref> In [[phonetics]], the word refers to sounds produced by the [[vocal tract]]. In [[acoustics]], it refers to resonance in sound sources, notably [[musical instruments]], as well as that of sound chambers. However, it is equally valid to talk about the formant frequencies of the air in a room, as exploited, for example, by [[Alvin Lucier]] in his piece ''[[I Am Sitting in a Room]]''. ==Formants and phonetics== Formants are the distinguishing or meaningful frequency components of human [[Manner of articulation|speech]] and of [[singing]]. By definition, the information that humans require to distinguish between [[vowel]]s can be represented purely quantitatively by the frequency content of the vowel sounds. Formants are the characteristic [[Overtone|partial]]s that identify vowels to the listener. Most of these formants are produced by tube and chamber [[resonance]], but a few whistle tones derive from periodic collapse of [[Venturi effect]] low-pressure zones. The formant with the lowest frequency is called ''f''<sub>1</sub>, the second ''f''<sub>2</sub>, and the third ''f''<sub>3</sub>. Most often the two first formants, ''f''<sub>1</sub> and ''f''<sub>2</sub>, are enough to disambiguate the vowel. These two formants determine the quality of vowels in terms of the open/close and front/back dimensions (which have traditionally, though not entirely accurately, been associated with the position of the tongue). Thus the first formant ''f''<sub>1</sub> has a higher frequency for an open vowel (such as [a]) and a lower frequency for a close vowel (such as [i] or [u]); and the second formant ''f''<sub>2</sub> has a higher frequency for a front vowel (such as [i]) and a lower frequency for a back vowel (such as [u]).<ref>Ladefoged, Peter (2006) ''A Course in Phonetics (Fifth Edition)'', Boston, MA: Thomson Wadsworth, p. 188. ISBN 1-4130-2079-8</ref><ref>Ladefoged, Peter (2001) ''Vowels and Consonants: An Introduction to the Sounds of Language'', Maldern, MA: Blackwell, p. 40. ISBN 0-631-21412-7</ref> Vowels will almost always have four or more distinguishable formants; sometimes there are more than six. However, the first two formants are most important in determining vowel quality, and this is often displayed in terms of a plot of the first formant against the second formant,<ref>Deterding, David (1997) 'The Formants of Monophthong Vowels in Standard Southern British English Pronunciation', ''Journal of the International Phonetic Association'', 27, pp. 47-55.</ref> though this is not sufficient to capture some aspects of vowel quality, such as rounding.<ref>Hayward, Katrina (2000) ''Experimental Phonetics'', Harlow, UK: Pearson, p. 149. ISBN 0-582-29137-2</ref> Nasals usually have an additional formant around 2500 Hz. The liquid {{IPA|[l]}} usually has an extra formant at 1500 Hz, while the [[english language|English]] "r" sound ({{IPA|[ɹ]}}) is distinguished by virtue of a very low third formant (well below 2000 Hz). [[Plosives]] (and, to some degree, [[Fricative consonant|fricatives]]) modify the placement of formants in the surrounding vowels. [[Bilabial]] sounds (such as 'b' and 'p' as in "ball" or "sap") cause a lowering of the formants; [[Velar consonant|velar]] sounds ('k' and 'g' in English) almost always show ''f''<sub>2</sub> and ''f''<sub>3</sub> coming together in a 'velar pinch' before the velar and separating from the same 'pinch' as the velar is released; [[Alveolar consonant|alveolar]] sounds (English 't' and 'd') cause less systematic changes in neighboring vowel formants, depending partially on exactly which vowel is present. The time-course of these changes in vowel formant frequencies are referred to as 'formant transitions'. If the fundamental frequency of the underlying vibration is higher than the formant frequency of the system, then the character of the sound imparted by the formant frequencies will be mostly lost. This is most apparent in the example of [[soprano]] [[opera]] singers, who sing high enough that their vowels become very hard to distinguish. Control of formants is an essential component of the vocal technique known as [[overtone singing]], in which the performer sings a low fundamental tone, and creates sharp resonances to select upper [[harmonics]], giving the impression of several tones being sung at once. [[Spectrogram]]s are used to visualise formants. <br> {| class="wikitable" style="margin:auto;text-align:center;" |+'''Vowel formant centers''' |- ! Vowel ! IPA ! Formant ''f''<sub>1</sub> ! Formant ''f''<sub>2</sub> |- | {{IPA|u}} || |u || '''320 Hz''' || 800 Hz |- | {{IPA|o}} || |o || '''500 Hz''' || 1000 Hz |- | {{IPA|ɑ}} || |{{IPA|ɑ}} || '''700 Hz''' || 1150 Hz |- | {{IPA|a}} || |a || '''1000 Hz''' || 1400 Hz |- | {{IPA|ø}} || |ø || 500 Hz || '''1500 Hz''' |- | {{IPA|y}} || |y || 320 Hz || '''1650 Hz''' |- | {{IPA|æ}} || |{{IPA|ɛ}} || 700 Hz || '''1800 Hz''' |- | {{IPA|e}} || |e || 500 Hz || '''2300 Hz''' |- | {{IPA|i}} || |i || 320 Hz || '''2500 Hz''' |} <br> {| class="wikitable" style="margin:auto;text-align:center;" |+'''Vowel formants''' |- ! Vowel ! Main formant region |- | align="center"| {{IPA|u}} || 200–400 Hz |- | align="center"| {{IPA|o}} || 400–600 Hz |- | align="center"| {{IPA|a}} || 800–1200 Hz |- | align="center"| {{IPA|e}} || 400–600 and 2200–2600 Hz |- | align="center"| {{IPA|i}} || 200–400 and 3000–3500 Hz |} ==Singers' formant== Studies of the frequency spectrum of trained [[singing|singers]], especially male singers, indicate a clear formant around 3000 Hz (between 2800 and 3400) that is absent in speech or in the spectra of untrained singers. It is increase in energy at 3000Hz which allows singers to be heard and understood over an [[orchestra]], which peak at much lower frequencies of around 500 Hz. This formant is actively developed through [[vocal training]], for instance through so-called ''"[[voce di strega]]"'' or witch's voice<ref name="FrisellBrandenBooks">{{cite book |author=Frisell, Anthony |title=Baritone Voice |publisher=Branden Books |location=Boston |year=2007 |pages=84 |isbn=0-8283-2181-7 |oclc= |doi=}}</ref> exercises and is caused by a part of the vocal tract acting as a [[Helmholtz resonator|resonator]].<ref name="SingersFormantNationalCenter">{{cite web|title=Vocal Ring, or The Singer's Formant|work=The National Center for Voice and Speech|url=http://www.ncvs.org/ncvs/tutorials/voiceprod/tutorial/singer.html |accessdate=2008-04-07}}</ref><ref name="Sundberg">{{cite book |author=Sundberg, Johan |title=The science of the singing voice |publisher=Northern Illinois University Press |location=DeKalb, Ill |year=1987 |pages= |isbn=0-87580-542-6 |oclc= |doi=}}</ref> ==See also== *[[Praat]] *[[Vocoder]] *[[Linear predictive coding]] *[[Human Voice]] ==References== <references/> ==External links== *[http://www.ling.lu.se/persons/Sidney/praate/whatform.html What are formants?] *[http://ccms.ntu.edu.tw/~karchung/Phonetics%20II%20page%20nineteen.htm Formants for fun and profit] *[http://www.geofex.com/Article_Folders/wahpedl/voicewah.htm Formants and wah-wah pedals] * [http://www.phys.unsw.edu.au/jw/soprane.html Formant tuning by soprano singers] from the University of New South Wales * [http://www.phys.unsw.edu.au/jw/xoomi.html The acoustics of harmonic or overtone singing] from the University of New South Wales *[http://videoweb.nie.edu.sg/phonetic/vowels/measurements.html Materials for measuring and plotting vowel formants] {{Sound synthesis types}} [[Category:Sound]] [[Category:phonetics]] [[cs:Formant]] [[de:Formant]] [[es:Formante]] [[eo:Formanto]] [[fr:Formant]] [[gl:Formante (fonética)]] [[he:פורמנט]] [[nl:Formant]] [[ja:フォルマント]] [[pl:Formant (elektroakustyka)]] [[sv:Formant]]