Christopher CarignanUniversity College London | UCL · Department of Speech, Hearing and Phonetic Sciences
Christopher Carignan
PhD
About
65
Publications
16,644
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
757
Citations
Introduction
Laboratory phonetician specializing in the relation between physical articulatory gestures of speech and the corresponding acoustic output, with a focus on many-to-one articulatory-acoustic mappings, computational modeling of how multimodal vocal tract actions relate to the acoustic signal, and innovations in computational techniques to process and analyze large-scale speech kinematic data.
Additional affiliations
November 2017 - present
August 2013 - June 2015
June 2015 - October 2017
Publications
Publications (65)
Previous research has shown that prosodic structure can regulate the relationship between co-speech gestures and speech itself. Most co-speech studies have focused on manual gestures, but head movements have also been observed to accompany speech events by Munhall, Jones, Callan, Kuratate, and Vatikiotis-Bateson [(2004). Psychol. Sci. 15(2), 133-13...
Among the variety of methodological tools available for quantifying the degree of nasalization, nasometry has remained a popular choice for both academic and clinical research on speech due to its relatively low cost, portability, ease of use, and interpretability. In its simplest form, nasometry involves two microphones that independently capture...
This paper examines the timing of anticipatory nasalization in French and relates it to individual speakers' realizations of phonologically nasal vowels. We explore the possibility that coarticulation in VN sequences is more extensive for speakers who only differentiate nasal and oral vowels to a limited extent based on nasality. Nasal intensity wa...
Nasal coarticulation is when the lowering of the velum for a nasal consonant co-occurs with the production of an adjacent vowel, causing the vowel to become (at least partially) nasalized. In the case of anticipatory nasal coarticulation, enhanced coarticulatory magnitude on the vowel facilitates the identification of an upcoming nasal coda consona...
Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis that can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time....
Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis which can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time...
This paper presents exploratory research on temporally dynamic patterns of vowel nasalization from two speakers of Arabana. To derive a dynamic measure of nasality, we use gradient tree boosting algorithms to statistically learn the mapping between acoustics and vowel nasality in a speaker-specific manner. Three primary findings emerge: (1) NVN con...
Velum movement signals generated from real-time magnetic resonance imaging videos of thirty-five German speakers were used to investigate the physiological conditions that might promote sound change involving the development of contrastive vowel nasality. The results suggest that, in comparison to when a nasal consonant precedes a voiced obstruent,...
Research on the temporal dynamics of /l/ production has focused primarily on mid-sagittal tongue movements. This study reports how known variations in the timing of mid-sagittal gestures are related to para-sagittal dynamics in /l/ formation in Australian English (AusE), using three-dimensional electromagnetic articulography (3D EMA). The articulat...
This paper presents a method of exploring the relative predictive importance of individual variables in multicollinear data sets at three levels of significance: strong importance, moderate importance, and no importance. Implementation of Bonferroni adjustment to control for Type I error in the method is described, and results with and without the...
This paper presents a method of exploring the relative predictive importance of individual variables in multicollinear data sets at three levels of significance: strong importance, moderate importance, and no importance. Implementation of Bonferroni adjustment to control for Type I error in the method is described, and results with and without the...
Previous research has shown that rhythmic head movement accompanies F0 modulations in speech (Munhall et al., 1994) and that this co-verbal head movement may be linked to prosodic features such as pitch accents and prosodic boundaries (Esteve-Gibert et al., 2017; Hadar et al., 1984; House et al., 2001). In this study, we examined how the production...
This paper presents an acoustic analysis of Mixean Low Navarrese, an endangered variety of Basque. The manuscript includes an overview of previous acoustic studies performed on different Basque varieties in order to synthesize the sparse acoustic descriptions of the language that are available. This synthesis serves as a basis for the acoustic anal...
We present a method of using generalized additive mixed models (GAMMs) to analyze midsagittal vocal tract data obtained from real-time magnetic resonance imaging (rt-MRI) video of speech production. Applied to rt-MRI data, GAMMs allow for observation of factor effects on vocal tract shape throughout two key dimensions: time (vocal tract change over...
A field-based ultrasound and acoustic study of Iwaidja, an endangered Australian Aboriginal language, investigates the phonetic identity of nonnasal velar consonants in intervocalic position, where past work has proposed a [+continuant] vs. [−continuant] phonemic contrast. We analyze the putative contrast within a continuous phonetic space, defined...
This paper presents an acoustic analysis of Mixean Low Navarrese, an endangered variety of Basque. The manuscript includes an overview of previous acoustic studies performed on different Basque varieties, in order to synthesize the sparse acoustic descriptions of the language that are available. This synthesis serves as a basis for the acoustic ana...
In this paper, a summary is given of an experimental technique to address a known issue in research on the independent effects of nasalization on vowel acoustics: given that the separate transfer functions associated with the oral and nasal cavities are merged in the acoustic signal, the task of teasing apart the respective effects of the two cavit...
It has been suggested that the development of contrastive vowel nasality in VN sequences may depend partly on the nature of the following consonant. In particular, there may be a preference for VN sequences preceding voiceless oral consonants to be phonologized due to aerodynamic constraints on velum height, resulting in temporal overlap of the vow...
We present the results of a forced-choice gating experiment to test the accuracy of same- and crossdialectal perception of phonemic nasal vowel contrasts in two dialects of French. We found that contrasts were identified with high accuracy, but differences in the phonetic realizations of vowels involved in ongoing chain shifts lead to confusion bet...
Using real-time MRI data related to velum movement in German, we find evidence that the effects of the aerodynamic constraint of a voiceless consonant in /VNC/ sequences are: temporal truncation of the velum gesture, reduction of the gesture magnitude, and shifting of the gesture peak toward the vowel. These effects may be the catalyst for a later...
Description: R function to convert an audio file to a 3D spectrogram and (optionally) save as a stereolithography (STL) file for 3D printing
Using articulation, acoustics, and perception data to tackle difficult questions in speech research, including sound change actuation (demonstrated in this talk).
Presented to the department of Speech, Hearing and Phonetic Sciences at University College London.
Using real-time MRI data from German, we find evidence that the phonologization of vowel nasalization involves at least three steps, which occur in the following order:
1) The velum gesture is truncated (decreased N nasality);
2) The velum gesture aligns with the vowel interval (increased V nasality);
3) The oral gesture for the nasal consonant...
The sequence (au) before nasals in Middle English, which has traditionally been assumed to have been a diphthong, does not follow the same diachronic patterns as in other sequences. In this presentation, a pilot study study is presented that uses laboratory production and perception techniques to investigate the possibility that the sequence (au) b...
This study represents an exploratory analysis of a novel method of investigating variation among individual speakers with respect to the articulatory strategies used to modify acoustic characteristics of their speech. Articulatory data (nasalization, tongue height, breathiness) and acoustic data (F1 frequency) related to the distinction of three na...
New methods of ultrasound analysis were developed to evaluate a pattern of intervocalic stop lenition in Iwaidja, an endangered language spoken in Northern Australia. Previous descriptions posit a phonemic contrast between a velar stop and a velar approximant in the leniting environment. Field-based ultrasound recordings of both putative velar cons...
This study was designed to test whether listener-based sound change—listener misperception (Ohala, 1981, 1993) and perceptual cue re-weighting (Beddor, 2009, 2012)—can be observed synchronically in a laboratory setting. Co-registered articulatory data (degree of nasalization, tongue height, breathiness) and acoustic data (F1 frequency) related to t...
When using ultrasound imaging of the tongue for speech recording/research, submental transducer stabilization is required to prevent the ultrasound transducer from translating or rotating in relation to the tongue. An iterative prototype of a lightweight three-dimensional-printable wearable ultrasound transducer stabilization system that allows fle...
Limited access to speakers and incomplete lexical knowledge are common challenges facing phonetic description of under-documented languages. We address these challenges by taking a multi-dimensional approach, seeking to constrain our phonetic description by covariation across acoustic and articulatory parameters. We demonstrate the approach through...
The experimental method described in this manuscript offers a possible means to address a well known issue in research on the independent effects of nasalization on vowel acoustics: given that the separate transfer functions associated with the oral and nasal cavities are merged in the acoustic signal, the task of teasing apart the respective effec...
This paper presents results of a simultaneous acoustic and articulatory investigation of word-medial and word-final geminate/singleton coronal stop contrasts in Moroccan Arabic (MA). The acoustic analysis revealed that, only for the wordmedial contrast, the two MA speakers adopted comparable strategies in contrasting geminates with singletons, main...
This study investigated the dynamics of lateral channel formation of /l/ in Australian-accented English (AusE) using 3D electromagnetic articulography (EMA). Coils were placed on the tongue both mid-sagitally and para-sagitally. We varied the vowel precedi /l/ between /I/ and /æ/ /a.g, filbert vs. talbot, and the syllable position of /l/, e.g., /'t...
When addressing their young infants, parents systematically modify their speech. Such infant-directed speech (IDS) contains exaggerated vowel formants, which have been proposed to foster language development via articulation of more distinct speech sounds. Here, this assumption is rigorously tested using both acoustic and, for the first time, fine-...
In a variety of languages, changes in tongue height and breathiness have been observed to covary with nasalization in both phonetic and phonemic vowel nasality. It has been argued that this covariation stems from speakers using multiple articulations to enhance F1 modulation and/or from listeners misperceiving the articulatory basis for F1 modifica...
Most dialects of North American English exhibit /æ/-raising in some phonological contexts. Both the conditioning environments and the temporal dynamics of the raising vary from region to region. To explore the articulatory basis of /æ/-raising across North American English dialects, acoustic and articulatory data were collected from a regionally di...
In studies of dialect variation, the articulatory nature of vowels is sometimes inferred from formant values using the following heuristic: F1 is inversely correlated with tongue height and F2 is inversely correlated with tongue backness. This study compared vowel formants and corresponding lingual articulation in two dialects of English, standard...
While real-time magnetic resonance imaging (rt-MRI) provides high spatiotemporal resolution for speech research, the associated audio is noisy, presenting a challenge for research on the relationship between articulation and the acoustic signal and solving the articulatory inversion problem. Using state-of-the-art denoising methods, the current stu...
Ultrasound imaging is of interest to many dialectologists, due to the relative trans- portability and low cost associated with this technique for imaging the tongue. The current study introduces a method for examining the temporal dynamics of artic- ulatory correlates of sociolinguistic variables directly from ultrasound video. This technique is de...
Of great interest to many phoneticians, phonologists, and historical linguists is the nature of the genesis of sound change processes—the inception of sound change, or how and why sound changes occur. In earlier works (Recasens et al., 1997; Recasens, 2006) Daniel Recasens and colleagues postulate that, to a large extent, sound change processes can...
A common simplifying technique in ultrasound studies of variation is to select a single representative frame for each token, sacrificing dynamic information that is often critical for understanding the phonetic motivations of phonological phenomena. We examine the phonetic motivations for tongue body raising in English /æ/ tensing (e.g., Labov et a...
It is well known that, for nasal vowels, traditional estimation of the shape of the vocal tract via inference from acoustic characteristics is complicated by the acoustic effects of velopharyngeal coupling (i.e. nasalization). Given this complexity, measuring the shape of the vocal tract directly is, perhaps, a more desirable method of assessing or...
While ultrasound imaging has made articulatory phonetics more accessible, quantitative analysis of ultrasound data often reduces speech sounds to tongue contours traced from single video frames, disregarding the temporal aspect of speech. We propose a tracing-free method for directly converting entire ultrasound videos to phonetically interpretable...
This study includes results of an articulatory (electromagnetic articulography, i.e. EMA) and acoustic study of the realizations of three oral–nasal vowel pairs /a/–/ɑ̃/, /ε/–/ε̃/, and /o/–/ɔ̃/ recorded from 12 Northern Metropolitan French (NMF) female speakers in laboratory settings. By studying the position of the tongue and the lips during the p...
PurposeTo enable dynamic speech imaging with high spatiotemporal resolution and full-vocal-tract spatial coverage, leveraging recent advances in sparse sampling.Methods
An imaging method is developed to enable high-speed dynamic speech imaging exploiting low-rank and sparsity of the dynamic images of articulatory motion during speech. The proposed...
TRACTUS (Temporally Resolved Articulatory Configuration Tracking of UltraSound) is a suite of Matlab (Mathworks, 2014) functions designed to perform temporal articulatory analysis on ultrasound images without the need for tracing of tongue contours. This software suite is freely available for download at the website address below (Carignan, 2014)....
Complexity in the acoustics of nasal vowels has long been acknowledged but complexity in their articulation has received less attention. A growing body of research suggests that velopharyngeal (VP) opening is complemented by other articulatory gestures which may enhance or counteract the acoustic outcomes of VP opening. In this paper we consider th...
There is increasing evidence that fine articulatory adjustments are made by speakers to reinforce and sometimes counteract the acoustic consequences of nasality. However, it is difficult to attribute the acoustic changes in nasal vowel spectra to either oral cavity configuration or to velopharyngeal opening (VPO). This paper takes the position that...
In acoustic studies of vowel nasalization, it is sometimes assumed that the primary articulatory difference between an oral vowel and a nasal vowel is the coupling of the nasal cavity to the rest of the vocal tract. Acoustic modulations observed in nasal vowels are customarily attributed to the presence of additional poles affiliated with the naso-...
A combination of aerodynamic and EPG instrumentation is used to estimate the relationship between velopharyngeal opening (VPO) and lin-guopalatal place of articulation for a variety of oral and nasal speech sounds. VPO values, estimated using the pressure-flow technique, are generally consistent with the results of previous aerodynamic studies, tho...
EMA, aerodynamic, and acoustic signals were combined in order to observe lingual and labial articulation of oral and nasal vowels produced by three Northern Metropolitan French (NMF) female speakers and two Quebec French (QF) female speakers. Inter-speaker variation observed in oral articulation suggests the importance of motor equivalence in the a...
It is well known that the vertical position of the larynx changes during speech:it is related to f0, vowel quality, and voicing. However, estimation of vertical larynx position has proven to be a significant challenge. This paper represents a proof-of-concept that electromagnetic articulography (EMA) can be used to detect differences in vertical la...