/tɹ/ and /dɹ/ in North American English: Phonologization of a Coarticulatory Effect
Creators: name: Magloughlin, Lyra
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2018
Subjects: articulatory phonetics
ultrasound study
sound change
phonologization
apparent time study
English
phonetics
phonology
perception
production

description: This dissertation examines an observed sound pattern in North American English: the affrication of /tɹ/ and /dɹ/ before /ɹ/. This pattern, which has been reported in many dialects of English, results in words like tree and dream pronounced more like [tʃɹi] and [dʒɹim]. To the best of my knowledge, there have been no experimental investigations into this phenomenon. This research aims to fill that gap. The first phase of research involved conducting an Apparent Time Study, with the goal of answering the question (Q1): Is the phenomenon of /tɹ/ and /dɹ/ affrication in English a sound change in progress? During this initial phase of research, affrication of /tɹ/ and /dɹ/ was investigated as a possible sound change in progress using acoustic data from the Raleigh corpus (Dodsworth and Kohn, 2012) – a collection of sociolinguistic interviews conducted with English speakers born and raised in Raleigh, North Carolina. The second phase of research, a Production Study conducted in the North Carolina State University Phonology Lab in Raleigh, was designed to examine the interaction between articulators during participants’ productions of /t/ and /d/ before /ɹ/, and /t d tʃ dʒ/ before vowels. The goal was to answer the following question (Q2): Are English /t/ and /d/ in /tɹ/ and /dɹ/ clusters articulated like prevocalic [t] and [d], like prevocalic [tʃ] and [dʒ], like neither, or like both? This is an important question. Are participants producing [t]s and [d]s coarticulated with [ɹ] that, e.g., for aerodynamic reasons, simply sound like affricates, or have participants adopted a new articulatory target before /ɹ/, suggesting phonologization of a coarticulatory effect? The final phase of research, the Perception Study, conducted in the same lab, was designed to explore how listeners categorize affricated variants of /t/ before /ɹ/. It was reasoned that if speakers are producing affricated variants, and listeners are perceiving that affrication, listeners may categorize the variant as CH rather than T in a forced-choice spelling task. The Perception experiment consisted of a series of non-words because affricates in complex onsets are prohibited in English. As a result, English has no contrastive /tɹ/ - /tʃɹ/ sequences, meaning words produced as [tɹi] and [tʃɹi] are both likely to be categorized as tree by listeners, while non-words [tɹʌv] and [tʃɹʌv] may be categorized differently. The Perception Study attempts to answer the question (Q3): Do English speakers categorize affricated variants of /t/ found in /tɹ/ clusters as T or CH? Results showed that a sound change was underway for English speakers in Raleigh, North Carolina by the middle of the 20th century (Q1), that young English speakers were producing distinct articulatory targets for /t/ and /d/ in /tɹ/ and /dɹ/ sequences, and not simply [t]s and [d]s coarticulated with [ɹ] (Q2), and that these same speakers were categorizing affricated variants of /t/ as CH when taken outside of their natural phonetic environment, with some categorizing affricated variants of /t/ and phonological /tS/ similarly in pre-[ɹ] environments (Q3). Taken together, a clearer picture of the phenomenon of /tɹ/ and /dɹ/ affrication has begun to emerge.