{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T17:16:21Z","timestamp":1791047781693,"version":"4.1.0"},"reference-count":40,"publisher":"Acoustical Society of America (ASA)","issue":"4","content-domain":{"domain":["pubs.aip.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2010,10,1]]},"abstract":"<jats:p>The study investigated the articulatory basis of locus equations, regression lines relating F2 at the start of a Consonant-Vowel (CV) transition to F2 at the middle of the vowel, with C fixed and V varying. Several studies have shown that consonants of different places of articulation have locus equation slopes that descend from labial to velar to alveolar, and intercept magnitudes that increase in the opposite order. Using formulas from the theory of bivariate regression that express regression slopes and intercepts in terms of standard deviations and averages of the variables, it is shown that the slope directly encodes a well-established measure of coarticulation resistance. It is also shown that intercepts are directly related to the degree to which the tongue body assists the formation of the constriction for the consonant. Moreover, it is shown that the linearity of locus equations and the linear relation between locus equation slopes and intercepts originates in linearity in articulation between the horizontal position of the tongue dorsum in the consonant and to that in the vowel. It is concluded that slopes and intercepts of acoustic locus equations are measures of articulator synergy.<\/jats:p>","DOI":"10.1121\/1.3479538","type":"journal-article","created":{"date-parts":[[2010,10,19]],"date-time":"2010-10-19T13:15:29Z","timestamp":1287494129000},"page":"2021-2032","update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":54,"title":["Locus equations are an acoustic expression of articulator synergy"],"prefix":"10.1121","volume":"128","author":[{"given":"Khalil","family":"Iskarous","sequence":"first","affiliation":[{"name":"Haskins Laboratories , 300 George Street, New Haven, Connecticut 06511"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carol A.","family":"Fowler","sequence":"additional","affiliation":[{"name":"Haskins Laboratories , 300 George Street, New Haven, Connecticut 06511"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D. H.","family":"Whalen","sequence":"additional","affiliation":[{"name":"Haskins Laboratories , 300 George Street, New Haven, Connecticut 06511"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"231","published-online":{"date-parts":[[2010,10,18]]},"reference":[{"key":"2023072022162750800_c1","first-page":"241","volume-title":"Analyzing Linguistic Data: A Practical Introduction to Statistics","year":"2007"},{"key":"2023072022162750800_c2","first-page":"51","article-title":"Preservation of second formant transitions during simultaneous communication: A locus equation perspective","volume":"35","year":"2002","journal-title":"J. Speech Lang. Hear. Res."},{"key":"2023072022162750800_c3","first-page":"26","article-title":"Effect of speech rate and coarticulation strategies on the locus equation determination","volume-title":"Proceedings of the XIV ICPHS","author":"Elenius","year":"1995"},{"key":"2023072022162750800_c4","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/S0095-4470(19)31234-3","article-title":"Coarticulation resistance in English \/l\/","volume":"4","year":"1976","journal-title":"J. Phonetics"},{"key":"2023072022162750800_c5","doi-asserted-by":"crossref","first-page":"24","DOI":"10.3758\/BF03211916","article-title":"On the relevance of locus equations for production and perception of stop consonants","volume":"60","year":"1998","journal-title":"Percept. Psychophys."},{"key":"2023072022162750800_c6","doi-asserted-by":"publisher","first-page":"2380","DOI":"10.1121\/1.419622","article-title":"Locus equations in the light of articulatory modeling","volume":"102","year":"1997","journal-title":"J. Acoust. Soc. Am."},{"key":"2023072022162750800_c7","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1037\/0033-2909.112.1.155","article-title":"A power primer","volume":"112","year":"1992","journal-title":"Psychological Bulletin"},{"key":"2023072022162750800_c8","doi-asserted-by":"crossref","first-page":"864","DOI":"10.2307\/459542","article-title":"The physiological interpretation of sound spectrograms","volume":"66","year":"1951","journal-title":"Publications of the Modern Language Association of America"},{"key":"2023072022162750800_c9","first-page":"27","article-title":"Articulator point variability in the production of stop consonants","volume-title":"Neuromotor Speech Disorders","author":"Cannito","year":"1998"},{"key":"2023072022162750800_c10","first-page":"11","volume-title":"Dynamic Speech Models","year":"2006"},{"key":"2023072022162750800_c11","doi-asserted-by":"publisher","first-page":"417","DOI":"10.1016\/0167-6393(92)90047-B","article-title":"Second-formant locus patterns: An investigation of spontaneous French speech","volume":"11","year":"1992","journal-title":"Speech Commun."},{"key":"2023072022162750800_c12","volume-title":"Acoustic Theory of Speech Production","year":"1960"},{"key":"2023072022162750800_c13","doi-asserted-by":"crossref","first-page":"597","DOI":"10.3758\/BF03211675","article-title":"Invariants, specifiers, cues: An investigation of locus equations as information for place of articulation","volume":"55","year":"1994","journal-title":"Percept. Psychophys."},{"key":"2023072022162750800_c14","doi-asserted-by":"publisher","first-page":"199","DOI":"10.1016\/j.wocn.2004.10.003","article-title":"Parsing coarticulated speech in perception: Effects of coarticulation resistance","volume":"33","year":"2005","journal-title":"J. Phonetics"},{"key":"2023072022162750800_c15","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1177\/00238309000430010101","article-title":"Coarticulation resistance of American English consonants and its effects on transconsonantal vowel-to-vowel coarticulation","volume":"43","year":"2000","journal-title":"Lang Speech"},{"key":"2023072022162750800_c16","doi-asserted-by":"publisher","first-page":"97","DOI":"10.1044\/1092-4388(2007\/008)","article-title":"F2 locus equations: Phonetic descriptors of coarticulation in 17- to 22-month-old children","volume":"50","year":"2007","journal-title":"J. Speech Lang. Hear. Res."},{"key":"2023072022162750800_c17","doi-asserted-by":"publisher","first-page":"18","DOI":"10.1159\/000028423","article-title":"The role of perception in the sound change of velar palatalization","volume":"55","year":"1998","journal-title":"Phonetica"},{"key":"2023072022162750800_c18","volume-title":"Structural Equation Modeling with LISREL: Essentials and Advances","year":"1987"},{"key":"2023072022162750800_c19","first-page":"58","volume-title":"Acoustic Phonetics","year":"1948"},{"key":"2023072022162750800_c20","first-page":"43","article-title":"Second formant locus patterns as a measure of consonant-vowel coarticulation","volume":"5","year":"1987","journal-title":"PERILUS"},{"key":"2023072022162750800_c21","first-page":"101","article-title":"Consonant-vowel coarticulation in spontaneous speech and reference words","volume":"10","year":"1989","journal-title":"PERILUS"},{"key":"2023072022162750800_c22","doi-asserted-by":"publisher","first-page":"1773","DOI":"10.1121\/1.1918816","article-title":"Spectrographic study of vowel reduction","volume":"35","year":"1963","journal-title":"J. Acoust. Soc. Am."},{"key":"2023072022162750800_c23","doi-asserted-by":"publisher","first-page":"3802","DOI":"10.1121\/1.2730622","article-title":"The effect of emphatic stress on consonant vowel coarticulation","volume":"121","year":"2007","journal-title":"J. Acoust. Soc. Am."},{"key":"2023072022162750800_c24","first-page":"8","article-title":"Articulatory and acoustic bases of locus equations","year":"2004"},{"key":"2023072022162750800_c25","doi-asserted-by":"publisher","first-page":"2022","DOI":"10.1121\/1.427948","article-title":"Interarticulator phasing, locus equations and degree of coarticulation","volume":"106","year":"1999","journal-title":"J. Acoust. Soc. Am."},{"key":"2023072022162750800_c26","first-page":"436","article-title":"Formant transitions: Teasing apart consonant and vowel contributions","volume-title":"Proceedings of the XIII ICPHS","author":"Elenius","year":"1995"},{"key":"2023072022162750800_c27","doi-asserted-by":"publisher","first-page":"2","DOI":"10.1159\/000078660","article-title":"Stop place coding: An acoustic study of CV, VC, and CV sequences","volume":"61","year":"2004","journal-title":"Phonetica"},{"key":"2023072022162750800_c28","first-page":"17","article-title":"Formant transitions are partly distinctive invariant properties in the identification of voiced stops","volume":"15","year":"1987","journal-title":"Can. Acoust."},{"key":"2023072022162750800_c29","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1177\/002383098502800201","article-title":"Coarticulatory patterns and degrees of coarticulatory resistance in Catalan CV sequences","volume":"28","year":"1985","journal-title":"Lang Speech"},{"key":"2023072022162750800_c30","doi-asserted-by":"publisher","first-page":"2288","DOI":"10.1121\/1.3089222","article-title":"An articulatory investigation of lingual coarticulatory resistance and aggressiveness for consonants and vowels in Catalan","volume":"125","year":"2009","journal-title":"J. Acoust. Soc. Am."},{"key":"2023072022162750800_c31","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/S0094-730X(96)00016-2","article-title":"Analysis of F2 transitions in the speech of stutterers and nonstutterers","volume":"22","year":"1997","journal-title":"J. Fluency Disord."},{"key":"2023072022162750800_c32","doi-asserted-by":"publisher","first-page":"333","DOI":"10.1207\/s15326969eco0104_2","article-title":"A dynamical approach to gestural patterning in speech production","volume":"1","year":"1989","journal-title":"Ecological Psychol."},{"key":"2023072022162750800_c33","first-page":"323","volume-title":"Acoustic Phonetics","year":"1998"},{"key":"2023072022162750800_c34","doi-asserted-by":"publisher","first-page":"294","DOI":"10.1006\/brln.1999.2182","article-title":"A neural mapping hypothesis to explain why velar stops have an allophonic split","volume":"70","year":"1999","journal-title":"Brain Lang"},{"key":"2023072022162750800_c35","doi-asserted-by":"publisher","first-page":"241","DOI":"10.1017\/S0140525X98001174","article-title":"Linear correlates in the speech signal: The orderly output constraint","volume":"21","year":"1998","journal-title":"Behav. Brain Sci."},{"key":"2023072022162750800_c36","doi-asserted-by":"publisher","first-page":"1256","DOI":"10.1121\/1.408178","article-title":"A cross-linguistic investigation of locus equations as a phonetic descriptor for place of articulation","volume":"94","year":"1993","journal-title":"J. Acoust. Soc. Am."},{"key":"2023072022162750800_c37","doi-asserted-by":"publisher","first-page":"1309","DOI":"10.1121\/1.401923","article-title":"An investigation of locus equations as a source of relational invariance for stop place categorization","volume":"90","year":"1991","journal-title":"J. Acoust. Soc. Am."},{"key":"2023072022162750800_c38","doi-asserted-by":"publisher","first-page":"137","DOI":"10.1006\/jpho.2000.0110","article-title":"Coarticulation in CV syllables: A comparison of locus equation and EPG data","volume":"28","year":"2000","journal-title":"J. Phonetics"},{"key":"2023072022162750800_c39","volume-title":"Xray Microbeam Speech Production Database Users Handbook","year":"1994"},{"key":"2023072022162750800_c40","doi-asserted-by":"publisher","first-page":"812","DOI":"10.2307\/2979746","article-title":"On the theory of correlation","volume":"60","year":"1897","journal-title":"J. R. Stat. Soc."}],"container-title":["The Journal of the Acoustical Society of America"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.aip.org\/asa\/jasa\/article-pdf\/128\/4\/2021\/13783770\/2021_1_online.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.aip.org\/asa\/jasa\/article-pdf\/128\/4\/2021\/13783770\/2021_1_online.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,7,20]],"date-time":"2023-07-20T22:21:22Z","timestamp":1689891682000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.aip.org\/jasa\/article\/128\/4\/2021\/683336\/Locus-equations-are-an-acoustic-expression-of"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2010,10,1]]},"references-count":40,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2010,10,1]]}},"URL":"https:\/\/doi.org\/10.1121\/1.3479538","relation":{},"ISSN":["0001-4966","1520-8524"],"issn-type":[{"value":"0001-4966","type":"print"},{"value":"1520-8524","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2010,10]]},"published":{"date-parts":[[2010,10,1]]}}}