La reducció fonètica de les vocals i els seus factors determinants

Main Article Content

José Alejandro Correa

Aquest article revisa les investigacions sobre la reducció fonètica de les vocals. La nostra exposició se centra en factors lingüístics com la durada, el context consonàntic, l’accent lèxic i les propietats lèxiques de les llengües (classe de mot, freqüència d’aparició, densitat de l’entorn fonològic). A més, es discuteixen els efectes de l’estil de parla, la velocitat d’elocució, les diferències fonètiques entre homes i dones, i la influència del bilingüisme i el contacte de llengües sobre el timbre vocàlic. Aquesta revisió mostra que l’estudi de la reducció fonètica de les vocals permet entendre els mecanismes generals de la producció i la percepció de la parla, les condicions del canvi fònic i la variació fonètica relacionada amb la identitat individual i social.

Paraules clau
reducció fonètica, reducció vocàlica, centralització, dispersió vocàlica, àrea de l’espai vocàlic (AEV)

Article Details

Com citar
Correa, José Alejandro. «La reducció fonètica de les vocals i els seus factors determinants». Estudios de fonética experimental, 2025, vol.VOL 34, p. 207-30, http://raco.cat/index.php/EFE/article/view/980000003469.
Referències

Aguilar, L., Machuca, M. J., & Martínez, G. (1991). Analysis of the Spanish sequence “de” in content words and in function words in continuous speech. In J. Llisterri (Ed.), Proceedings of ESCA Workshop on Phonetics and Phonology of Speaking Styles (Paper 007). ISCA. https://www.isca-archive.org/ppst_1991/aguilarcuevas91_ppst.html

Amir, N., & Amir, O. (2007). Novel measures for vowel reduction. In J. Trouvain & W. Barry (Eds.), Proceedings of the 16th International Congress of Phonetic Sciences (pp. 849–852). International Phonetic Association. http://www.icphs2007.de/conference/Papers/1035/index.html

Audibert, N., Fougeron, C., Gendrot, C., & Adda-Decker, M. (2015). Duration vs. style-dependent vowel variation: a multiparametric investigation. In The Scottish Consortium for ICPhS 2015 (Eds.), Proceedings of the 18th International Congress of Phonetic Sciences (Paper 0753). International Phonetic Association. https://www.internationalphoneticassociation.org/icphs-proceedings/ICPhS2015/Papers/ICPHS0753.pdf

Audibert, N., Fougeron, C., & Meunier, C. (2024). Do speaker-dependent vowel characteristics depend on speech style? In I. Lapidot & S. Gannot (Eds.), Proceedings of Interspeech 2024 (pp. 3669–3673). ISCA. https://doi.org/10.21437/Interspeech.2024-310

Aylett, M., & Turk, A. (2004). The smooth signal redundancy hypothesis: A functional explanation for the relationships between redundancy, prosodic prominence, and duration in spontaneous speech. Language and Speech, 47(1), 31–56. https://doi.org/10.1177/00238309040470010201

Aylett, M., & Turk, A. (2006). Language redundancy predicts syllabic duration and the spectral characteristics of vocalic nuclei. The Journal of the Acoustical Society of America, 119(5), 3048–3058. https://doi.org/10.1121/1.2188331

Barnes, J. (2006). Strength and weakness at the interface: Positional neutralization in phonetics and phonology. De Gruyter Mouton. https://doi.org/10.1515/9783110197617

Barry, W., & Andreeva, B. (2001). Cross-language similarities and differences in spontaneous speech patterns. Journal of the International Phonetic Association, 31(1), 51–66. https://doi.org/10.1017/S0025100301001050

Bell, A., Breiner, J., Gregory, M. G., & Jurafsky, D. (2009). Predictability effects on durations of content and function words in conversational English. Journal of Memory and Language, 60(1), 92–111. https://doi.org/10.1016/j.jml.2008.06.003

Bradlow, A. R. (1995). A comparative acoustic study of English and Spanish vowels. The Journal of the Acoustical Society of America, 97(3), 1916–1924. https://doi.org/10.1121/1.412064

Bosque, I. (1990). Las categorías gramaticales. Síntesis.

Burdin, R. S., & Clopper, C. G. (2015). Phonetic reduction, vowel duration, and prosodic structure. In The Scottish Consortium for ICPhS 2015 (Eds.), Proceedings of the 18th International Congress of Phonetic Sciences (Paper 0378). International Phonetic Association. https://www.internationalphoneticassociation.org/icphs-proceedings/ICPhS2015/Papers/ICPHS0378.pdf

Bybee, J. (2001). Phonology and language use. Cambridge University Press. https://doi.org/10.1017/CBO9780511612886

Bybee, J. (2002). Word frequency and context of use in the lexical diffusion of phonetically conditioned sound change. Language Variation and Change, 14, 261–290. https://doi.org/10.1017/S0954394502143018

Bybee, J., File-Muriel, R., & Napoleão de Souza, R. (2016). Special reduction: a usage-based approach. Language and Cognition, 8(3), 421–446. https://doi.org/10.1017/langcog.2016.19

Byrd, D. (1994). Relations of sex and dialect to reduction. Speech Communication, 15(1–2), 39–54. https://doi.org/10.1016/0167-6393(94)90039-6

Carbonell, J., & Llisterri, J. (1992). Catalan. Journal of the International Phonetic Association, 22(1–2), 53-56. https://doi.org/10.1017/S0025100300004618

Catford, J. C. (1977). Fundamental problems in phonetics. Indiana University Press.

Catford, J. C. (1990). A proposal concerning central vowels. Journal of the International Phonetic Association, 20(2), 26–28. https://doi.org/10.1017/S0025100300004230

Chiba, T., & Kajiyama, M. (1958). The vowel: Its nature and structure. Phonetic Society of Japan.

Chládkova, K., Escudero, P., & Boersma, P. (2011). Context-specific acoustic differences between Peruvian and Iberian Spanish vowels. The Journal of the Acoustical Society of America, 130(1), 416–428. https://doi.org/10.1121/1.3592242

Chomsky, N., & Halle, M. (1968). The sound pattern of English. Harper & Row Publishers.

Clopper, C., & Turnbull, R. (2018). Exploring variation in phonetic reduction: Linguistic, social, and cognitive factors. In F. Cangemi, M. Clayards, O. Niebuhr, B. Schuppler, & M. Zellers (Eds.), Rethinking reduction: Interdisciplinary perspectives on conditions, mechanisms, and domains for phonetic variation (pp. 25–72). Walter de Gruyter. https://doi.org/10.1515/9783110524178-002

Correa, J. A. (2017). Caracterización acústica de la reducción vocálica en el español hablado en Bogotá (Colombia). Estudios de Fonética Experimental, 26(1), 63–91. https://revistes.ub.edu/index.php/experimentalphonetics/article/view/44062

Correa, J. A. (2021a). Reducción fonética de las vocales del español de Bogotá (Colombia) [Doctoral dissertation, Universitat Autònoma de Barcelona]. Dipòsit Digital de Documents de la UAB. https://www.tdx.cat/handle/10803/673154

Correa, A. (2021b). Sexo, espacio acústico y centralización de las vocales del español de Bogotá. Loquens, 8(1–2), e84. https://doi.org/10.3989/loquens.2021.084

Correa, J. A., & Rodríguez, L. C. (2018). Reducción fonética de la secuencia consonántica /-st-/ en el español de Bogotá. Estudios Filológicos, 62, 193–214. https://doi.org/10.4067/S0071-17132018000200193

Correa, A., & Rodríguez, L. C. (2024). Las vocales caedizas del español bogotano. Lexis, 48(1), 337–369. https://doi.org/10.18800/lexis.202401.011

De Carvalho, F. (2010). Vowel acoustics in Pirahã. Revista de Estudos da Linguagem, 18(1), 11–33. https://doi.org/10.17851/2237-2083.18.1.11-33

De Jong, K. (1995). The supraglottal articulation of prominence in English: Linguistic stress as localized hyperarticulation. The Journal of the Acoustical Society of America, 97(1), 491–504. https://doi.org/10.1121/1.412275

Delattre, P. (1969). An acoustic and articulatory study of vowel reduction in four languages. IRAL - International Review of Applied Linguistics in Language Teaching, 7(4), 295–325. https://doi.org/10.1515/iral.1969.7.4.295

Delforge, A. M. (2008). Unstressed vowel reduction in Andean Spanish. In L. Colantoni & J. Steele (Eds.), Proceedings of the 3rd Conference on Laboratory Approaches to Spanish Phonology (pp. 107–124). Cascadilla Proceedings Project. https:// www.lingref.com/cpp/lasp/3/paper1718.pdf

DiCanio, C., Nam, H., Amith, J., & Castillo García, R. (2015). Vowel variability in elicited versus spontaneous speech: evidence from Mixtec. Journal of Phonetics, 48, 45–59. https://doi.org/10.1016/j.wocn.2014.10.003

Engstrand, O. (1988). Articulatory correlates of stress and speaking rate in Swedish. The Journal of the Acoustical Society of America, 83(5), 1863–1875. https://doi.org/10.1121/1.396522

Engstrand, O., & Krull, D. (1988). On the systematicity of phonetic variation in spontaneous speech. PERILUS, 8, 34–47.

Engstrand, O. (1992). Systematicity of phonetic variation in natural discourse. Speech Communication, 11, 337–346. https://doi.org/10.1016/0167-6393(92)90039-A

Ericsdotter, C., & Ericsson, A. (2001). Gender differences in vowel duration in read Swedish: Preliminary results. In Proceedings from Fonetik 2001, XIVth Swedish Phonetics Conference. Working Papers of the Department of Linguistics, Lund University, 49, (pp. 34–37). Lund University.

Fant, G. (1966). A note on vocal tract size factors and non-uniform F-pattern scalings. STL-Quarterly Progress and Status Report, 7(4), 22–30.

Fant, G. (1970). Acoustic theory of speech production. Mouton. (Original work published 1960). https://doi.org/10.1515/9783110873429

Fant, G. (1975). Non-uniform vowel normalization. STL- Quarterly Progress and Status Report, 16(1–3), 1–19.

Flemming, E. (2005). A phonetically-based model of phonological reduction [Unpublished manuscript]. MIT. https://web.mit.edu/flemming/www/paper/vowelred.pdf

Flemming, E. (2009). The phonetics of schwa vowels. In D. Minkova (Ed.), Phonological weakness in English: From old to present-day English (pp. 78–95). Palgrave Macmillan.

Fourakis, M. (1991). Tempo, stress, and vowel reduction in American English. The Journal of the Acoustical Society of America, 90(4), 1816–1827. https:// doi.org/10.1121/1.401662

Gahl, S., Yao Y., & Johnson, K. (2012). Why reduce? Phonological neighborhood density and phonetic reduction in spontaneous speech. Journal of Memory and Language, 66, 789–806. https://doi.org/10.1016/j.jml.2011.11.006

Gay, T. (1978). Effect of speaking rate on vowel formant movements. The Journal of the Acoustical Society of America, 63(1), 223–230. https://doi.org/10.1121/1.381717

Gendrot, C., & Adda-Decker, M. (2007). Impact of duration and vowel inventory size on formant values of oral vowels: An automated formant analysis from eight languages. In J. Trouvain & W. Barry (Eds.), Proceedings of the 16th International Congress of Phonetic Sciences (pp. 1417–1420). International Phonetic Association. http://www.icphs2007.de/conference/Papers/1481/index.html

Gendrot, C., Adda-Decker, M., & Santiago, F. (2019). Acoustic realization of vowels as a function of syllabic position. A crosslinguistic study with data from French and Spanish. In M. Gibson & J. Gil (Eds.), Romance Phonetics and Phonology (pp. 77–88). Oxford University Press. https://doi.org/10.1093/oso/9780198739401.003.0005

Gil, J. (2007). Fonética para profesores del español: de la teoría a la práctica. Arco/Libros.

Goldstein, U. G. (1980). An articulatory model for the vocal tracts of growing children [Doctoral dissertation, Massachusetts Institute of Technology]. MIT Libraries. http://hdl.handle.net/1721.1/22386

Harmegnies, B., & Poch-Olivé, D. (1992). A study of style-induced vowel variability: Laboratory versus spontaneous speech in Spanish. Speech Communication, 11, 429–437. https://doi.org/10.1016/0167-6393(92)90048-C

Harrington, J., & Cassidy, S. (1999). Techniques in speech acoustics. Springer. https://doi.org/10.1007/978-94-011-4657-9

Harris, K. (1978). Vowel duration change and its underlying physiological mechanisms. Language and Speech, 21(4), 354–361. https://doi.org/10.1177/002383097802100410

Hayward, K. (2000). Experimental phonetics: An introduction. Routledge. https://doi.org/10.4324/9781315842059

Holliday, N., & Martin, S. (2018). Vowel categories and allophonic lowering among Bolivian Quechua–Spanish bilinguals. Journal of the International Phonetic Association, 48(2), 199–222. https://doi.org/10.1017/S0025100317000512

International Phonetic Association. (1949). The principles of the International Phonetic Association. Department of Phonetics, University College of London.

International Phonetic Association. (1999). Handbook of the International Phonetic Association. Cambridge University Press. https://doi.org/10.1017/9780511807954

Jakobson, R., Fant, G., & Halle, M. (1969). Preliminaries to speech analysis: The distinctive features and their correlates. MIT Press.

Jaworski, S. (2009). Inertial and non-inertial lenition processes. Poznań Studies in Contemporary Linguistics, 45(1), 103–129. https://doi.org/10.2478/v10010-009-0006-6

Johnson, K. (2012). Acoustic and auditory phonetics. Wiley-Blackwell.

Jones, D. (1922). An outline of English phonetics. G. E. Stechert & Co.

Joos, M. (1948). Acoustic phonetics. Language, 24(2), 1–136. https://doi.org/10.2307/522229

Keating, P., Cho, T., Fougeron, C., & Hsu, C. (2004). Domain-initial articulatory strengthening in four languages. In J. Local, R. Ogden, & R. Temple (Eds.), Phonetic Interpretation: Papers in Laboratory Phonology VI (pp. 145–163). Cambridge University Press.

Kondo, Y. (1994). Targetless schwa: Is that how we get the impression of stress-timing in English? In Proceedings of the Edinburgh Linguistics Department Conference (pp. 63-76). The University of Edinburgh.

Koopmans-van Beinum, F., & Harder, J. (1982). Word classification, word frequency, and vowel reduction. In Proceedings from the Institute of Phonetic Sciences of the University of Amsterdam, 7, 61–69. University of Amsterdam.

Koopmans-van Beinum, F. (1983). Systematics in vowel systems. In M. von den Broecke, V. van Heuven, & W. Zonneveld (Eds.), Sound structures. Studies for Antonie Cohen (pp. 159–172). Foris Publications. https://doi.org/10.1515/9783110846270.159

Kuehn, D. P., & Moll, K. L. (1976). A cineradiographic study of VC and CV articulatory velocities. Journal of Phonetics, 4, 303–320. https://doi.org/10.1016/S0095-4470(19)31257-4

Labov, W. (1972). Some principles of linguistic methodology. Language in Society, 1(1), 97–120. https://doi.org/10.1017/S0047404500006576

Lengeris, A. (2012). Phonetic vowel reduction in Standard modern Greek. In Z. Gavriilidou, A. Efthymiou, E. Thomadaki, & P. Kambakis-Vougioklis (Eds.), Selected papers of the 10th International Conference of Greek Linguistics (pp. 401–407). Democritus University of Thrace.

Lieberman, P. (1963). Some effects of semantic and grammatical context on the production and perception of speech. Language and Speech, 6, 172–187. https://doi.org/10.1177/002383096300600306

Lindblom, B. (1963). Spectrographic study of vowel reduction. The Journal of Acoustical Society of America, 35(11), 1773–1781. https://doi.org/10.1121/1.2142410

Lindblom, B. (1990). Explaining phonetic variation: A sketch of the H&H theory. In W. Hardcastle & A. Marchal (Eds.), Speech Production and Speech Modelling (pp. 403–439). Kluwer. https://doi.org/10.1007/978-94-009-2037-8_16

Llisterri, J. (1991). Introducción a la fonética: el método experimental. Editorial Antropos.

Llisterri, J., Machuca, M., de la Mota, C. R., & Ríos, A. (2003). The perception of lexical stress in Spanish. In M. J. Solé, D. Recasens, & J. Romero (Eds.), Proceedings of the 15th International Congress of Phonetic Sciences (pp. 2023–2026). International Phonetic Association.

Luce, P. A., & Pisoni, D. B. (1998). Recognizing spoken words: The neighborhood activation model. Ear and Hearing, 19, 1–36. https://doi.org/10.1097/00003446-199802000-00001

Machuca Ayuso, M., & Poch-Olivé, D. (2016). Dinámica de las vocales del español en contacto con el catalán. Oralia, 19, 153–175. https://doi.org/10.25115/oralia.v19i1.7026

Martín-Butragueño, P. (2014). Vocales en contexto. In E. Herrera & R. Barriga (Eds.), Lenguas, estructuras y hablantes: estudios en homenaje a Thomas C. Smith Stark (pp. 971–992). El Colegio de México.

Meunier, C., & Espesser, R. (2011). Vowel reduction in conversational speech in French: The role of lexical factors. Journal of Phonetics, 39, 271–278. https:// doi.org/10.1016/j.wocn.2010.11.008

Moon, S-J., & Lindblom, B. (1994). Interaction between duration, context, and speaking style in English stressed vowels. The Journal of the Acoustical Society of America, 96(1), 40–55. https://doi.org/10.1121/1.410492

Mooshammer, C., & Geng, C. (2008). Acoustic and articulatory manifestations of vowel reduction in German. Journal of the International Phonetic Association, 38(2), 117–136. https://doi.org/10.1017/S0025100308003435

Munson, B. (2007). The acoustic correlates of perceived masculinity, perceived femininity, and perceived sexual orientation. Language and Speech, 50(1), 125–142. https://doi.org/10.1177/002383090705000106

Munson, B., & Solomon, N. (2004). The effect of phonological neighborhood density on vowel articulation. Journal of Speech, Language, and Hearing Research, 47, 1048–1058. https://doi.org/10.1044/1092-4388(2004/078)

Nadeu, M. (2014). Stress- and speech rate-induced vowel quality variation in Catalan. Journal of Phonetics, 46, 1–22. https://doi.org/10.1016/j.wocn.2014.05.003

Nicoladis, K. (2003). Acoustic variability of vowels in Greek Spontaneous Speech. In M. J. Solé, D. Recasens, & J. Romero (Eds.), Proceedings of the 15th International Congress of Phonetic Sciences (pp. 3221–3224). International Phonetic Association.

Niebuhr, O. (2014). A little more ironic: Voice quality and segmental reduction differences between sarcastic and neutral utterances. In N. Campbell, D. Gibbon, & D. Hirst (Eds.), Social and Linguistic Speech Prosody: Proceedings of the 7th International Conference on Speech Prosody (pp. 608–612). ISCA. https://doi.org/10.21437/SpeechProsody.2014-110

Niebuhr, O. (2016). Rich Reduction: Sound-segment residuals and the encoding of communicative functions along the hypo-hyper scale. In A. Botinis (Ed.), Proceedings of the 7th Tutorial & Research Workshop on Experimental Linguistics (pp. 11–24). https://doi.org/10.36505/ExLing-2016/07/0002/000261

Nord, L. (1986). Acoustic studies of vowel reduction in Swedish. STL Quarterly Progress and Status Report, 27(4), 19–36.

Oostendorp, M. (2003). Schwa in phonological theory. In L. Cheng & R. Sybesma (Eds.), The second glot international state-of-the-article book: The Latest in Linguistics (pp. 122–165). De Gruyter Mouton. https://doi.org/10.1515/9783110890952.431

O’Rourke, E. (2010). Dialect Differences and the Bilingual Vowel Space in Peruvian Spanish. In M. Ortega-Llebaria (Ed.), Selected Proceedings of the 4th Conference on Laboratory Approaches to Spanish Phonology (pp. 20–30). Cascadilla Proceedings Project.

Pierrehumbert, J. B., Bent, T., Munson, B., Bradlow, A. R., & Bailey, M. (2004). The influence of sexual orientation on vowel production (L). The Journal of The Acoustical Society of America, 116 (4), 1905–1908. https://doi.org/10.1121/1.1788729

Pfitzinger, H., & Niebuhr, O. (2011). Historical development of phonetic vowel systems- The last 400 years. In W.-S. Lee & E. Zee (Eds.), Proceedings of the 17th International Congress of Phonetic Sciences (pp. 160–163). International Phonetic Association.

Poch-Olivé, D., Harmegnies, B., & Martín Butragueño, P. (2008). Influencia del estilo de habla sobre las características de las realizaciones vocálicas en el español de México. Actas del XV Congreso Internacional ALFAL. Asociación de Lingüística y Filología de América Latina.

Recasens, D. (2019). Stressed /e/ Centralization into schwa and related mid vowel developments in Catalan and elsewhere in the Romania. Transactions of the Philological Society, 117, 294–316. https:// doi.org/10.1111/1467-968X.12159

Recasens, D. (2022). Acoustic characteristics and placement within vowel space of full schwa in the world’s languages: A survey. Journal of the International Phonetic Association, 52(1), 59–94. https://doi.org/10.1017/S0025100320000122

Rehor, C., & Pätzold, M. (1996). The phonetic realization of function words in German spontaneous speech. Arbeitsberichte des Instituts für Phonetik und digitale Sprachverarbeitung der Universität Kiel (AIPUK), 31, 5–10.

Romanelli, S., & Menegotto, A. C. (2018). Características acústicas de las vocales tónicas y átonas del español rioplatense. Efectos del estilo de habla y del contexto consonántico. Signo y Seña, 33, 157–179. https://doi.org/10.34096/sys.n33.5263

Ronquest, R. (2013). An acoustic examination of unstressed vowel reduction in Heritage Spanish. In C. E. Howe (Ed.), Selected Proceedings of the 15th Hispanic Linguistics Symposium (pp. 157–171). Cascadilla Proceedings Project.

Simpson, A. (2001a). Does articulatory reduction miss more patterns than it accounts for? Journal of the International Phonetic Association, 31(1), 29–39. https://doi.org/10.1017/S0025100301001037

Simpson, A. (2001b). Dynamic consequences of differences in male and female vocal tract dimensions. The Journal of the Acoustical Society of America, 109(5), 2153–2164. https://doi.org/10.1121/1.1356020

Simpson, A. (2002). Gender-specific articulatory-acoustic relations in vowel sequences. Journal of Phonetics, 30(3), 417–435. https://doi.org/10.1006/jpho.2002.0171

Simpson, A. (2009). Phonetic differences between male and female speech. Language and Linguistics Compass, 3(2), 621–640. https://doi.org/10.1111/j.1749-818X.2009.00125.x

Smiljanić, R., & Bradlow, A. R. (2009). Speaking and hearing clearly: Talker and listener factors in speaking style changes. Language and Linguistics Compass, 3(1), 236–264. https://doi.org/10.1111/j.1749-818X.2008.00112.x

Stevens, K. (1998). Acoustic Phonetics. MIT Press. https://doi.org/10.7551/mitpress/1072.001.0001

Stevens, K., & House, A. (1963). Perturbation of vowel articulations by consonantal context: an acoustical study. Journal of Speech, Language, and Hearing Research, 6(2), 111–128. https://doi.org/10.1044/jshr.0602.111

Van Bergem, D. R. (1993). Acoustic vowel reduction as a function of sentence accent, word stress, and word class. Speech Communication, 12(1), 1–23. https:// doi.org/10.1016/0167-6393(93)90015-D

Van Bergem, D. R. (1994). A model of coarticulatory effects on the schwa. Speech Communication, 14(2), 143–162. https://doi.org/10.1016/0167-6393(94)90005-1

Van Bergem, D. R. (1995). Perceptual and acoustic aspects of lexical vowel reduction, a sound change in progress. Speech Communication, 16(4), 329–358. https://doi.org/10.1016/0167-6393(95)00003-7

Van Son, R. J., & Pols, L. C. (1990). Formant frequencies of Dutch vowels in a text, read at normal and fast rate. The Journal of the Acoustical Society of America, 88(4), 1683–1693. https://doi.org/10.1121/1.400243

Van Son, R. J., & Pols, L. C. (1992). Formant movements of Dutch vowels in a text, read at normal and fast rate. The Journal of the Acoustical Society of America, 92(1), 121–127. https://doi.org/10.1121/1.404277

Van Son, R., Bolotonova, O., Lennes, M., & Pols, L. (2004). Frequency effects on vowel reduction in three typologically different languages (Dutch, Finnish, Russian). In S. H. Kim & D. H. Youn (Eds.), Proceedings of Interspeech (pp. 1277–1280). ISCA. https://doi.org/10.21437/Interspeech.2004-72

Wagner, N. (2019). Reduced speech: All is variability. WIREs Cognitive Science, 10(4), 1–7. https://doi.org/10.1002/wcs.1496

Weirich, M., & Simpson, A. (2014). Articulatory vowel spaces of male and female speakers. In S. Fuchs, M. Grice, A. Hermes, L. Lancia, & D. Mücke (Eds.), Proceedings of the 10th International Seminar on Speech Production (pp. 449–452). Universität zu Köln.

Weirich, M., & Simpson, A. (2015). Impact and interaction of accent realization of speaker sex on vowel length in German. In S. Schmid, V. Dellwo, A. Leemann, & M. J. Kolly (Eds.), Trends in Phonetics and Phonology: Studies from German-speaking Europe (pp. 109–123). Peter Lang.

Whiteside, S. (1996). Temporal-based acoustic-phonetic patterns in read speech: Some evidence for speaker sex differences. Journal of the International Phonetic Association, 26(1), 23–40. https://doi.org/10.1017/S0025100300005302

Wright, R. (2004). Factors of lexical competition in vowel articulation. In J. Local, R. Ogden, & R. Temple (Eds.), Papers in Laboratory Phonology VI (pp. 26–50). Cambridge University Press.