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 the productions of phonemic oral and nasal vowels of Southern French were first collected from four native speakers, and the acoustic recordings were subsequently presented to nine Australian English naïve listeners, who were instructed to imitate the native productions. During these imitations, similar articulatory and acoustic data were collected in order to compare the articulatory strategies used by the two groups. The results suggest that the imitators successfully reproduced the acoustic distinctions made by the native speakers, but that they did so using different articulatory strategies. The articulatory strategies for the vowel pair /ɑ̃/-/a/ suggest that listeners (at least partially) misperceived F1-lowering due to nasalization and breathiness as being due to tongue height. Additional evidence supports perceptual cue re-weighting, in that the naïve imitators employed nasalance less, and tongue height more, in order to obtain the same F1 nasal-oral distinctions that the native speakers had originally produced.
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-grained articulatory measures. Mothers were recorded speaking to their infant and to another adult, and measures were taken of their acoustic vowel space, their tongue and lip movements and the length of their vocal tract. Results showed that infant- but not adult-directed speech contains acoustically exaggerated vowels, and these are not the product of adjustments to tongue or to lip movements. Rather, they are the product of a shortened vocal tract due to a raised larynx, which can be ascribed to speakers' unconscious effort to appear smaller and more non-threatening to the young infant. This adjustment in IDS may be a vestige of early mother–infant interactions, which had as its primary purpose the transmission of non-aggressiveness and/or a primitive manifestation of pre-linguistic vocal social convergence of the mother to her infant. With the advent of human language, this vestige then acquired a secondary purpose—facilitating language acquisition via the serendipitously exaggerated vowels.
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 consonant. However, nasalization also affects the acoustic properties of the vowel, including formant frequencies. Thus, while anticipatory nasalization may help facilitate perception of a nasal coda consonant, it may at the same time cause difficulty in the correct identification of preceding vowels. Prior work suggests that the temporal degree of nasal coarticulation is greater in American English (US) than British English (UK), yet the perceptual consequences of these differences have not been explored. The current study investigates perceptual confusions for oral and nasalized vowels in US and UK TTS voices by US and UK listeners. We use TTS voices, in particular, to explore these perceptual consequences during human-computer interaction, which is increasing due to the rise of speech-enabled devices. Listeners heard words with oral and nasal codas produced by US and UK voices, masked with noise, and made lexical identifications from a set of options varying in vowel and coda contrasts. We find the strongest effect of speaker dialect on accurate word selection: overall accuracy is highest for UK Oral Coda words (83%) and lower for US Oral Coda words (67%); the lowest accuracy was for words with Nasal Codas in both dialects (UK Nasal = 61%; US Nasal = 60%). Error patterns differed across dialects: both listener groups made more errors in identifying nasal codas in words produced in UK English than those produced in US English. Yet, the rate of errors in identifying the quality of nasalized vowels was similarly lower than that of oral vowels across both varieties. We discuss the implications of these results for cross-dialectal coarticulatory variation, human-computer interaction, and perceptually driven sound change.
•Nasalization, breathiness, and tongue height are used to distinguish F1.•Increased nasalization and breathiness significantly predict F1-lowering.•Nasalization increases throughout the duration of ...the nasal vowels.•Results provide limited support for the realization of an excrescent nasal coda.•Breathiness increases in a gradient manner as nasalization increases.
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 modification. This study includes results from synchronous nasalance, ultrasound, EGG, and F1 data related to the realizations of the oral–nasal vowel pairs /ɛ/-/ɛ̃/, /a/-/ɑ̃/, and /o/-/ɔ̃/ of Southern French (SF) as produced by four male speakers in a laboratory setting. The aim of the study is to determine to what extent tongue height and breathiness covary with nasalization, as well as how these articulations affect the realization of F1. The following evidence is observed: (1) that nasalization, breathiness, and tongue height are used in idiosyncratic ways to distinguish F1 for each vowel pair; (2) that increased nasalization and breathiness significantly predict F1-lowering for all three nasal vowels; (3) that nasalization increases throughout the duration of the nasal vowels, supporting previous claims about the temporal nature of nasality in SF nasal vowels, but contradicting claims that SF nasal vowels comprise distinct oral and nasal elements; (4) that breathiness increases in a gradient manner as nasalization increases; and (5) that the acoustic and articulatory data provide limited support for claims of the existence of an excrescent nasal coda in SF nasal vowels. These results are discussed in the light of claims that the multiple articulatory components observed in the production of vowel nasalization may have arisen due to misperception-based sound change and/or to phonetic enhancement.
•Nasalization, tongue height, & breathiness contribute independently to F1 variation.•Network modeling allows bottom-up grouping of articulatory-to-acoustic strategies.•Group separation for ...nasal-oral vowel distinctions based primarily on tongue height.•Group separation is not based on language background, but speaker-dependent patterns.•A “nasal” vowel is not just velum lowering: it is articulatorily multi-dimensional.
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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 nasal-oral vowel contrasts in French were co-registered. Data were collected first from four Southern French (FR) speakers and, subsequently, from nine naïve Australian English listeners who imitated the FR productions. Articulatory measurements were mapped to F1 measurements using relative importance analysis (RIA), and the RIA coefficients were used to create similarity scores among all of the speakers. The similarity scores were then used to build network models for each nasal-oral vowel pair, using the spinglass algorithm to identify communities of shared articulatory-to-acoustic strategies within each network. The results show that network grouping is rarely based on language-dependent articulatory-to-acoustic strategies, but evidence of inter- and intra-speaker consistency is observed: Individual speakers tend to group together in their articulatory-to-acoustic strategies across vowel pairs, and most speakers have consistent articulatory-to-acoustic mappings across vowel pairs. Evidence is also observed which highlights the multi-dimensional nature of vowel nasality, rather than the uni-dimensional assumption of “nasal” vowels as merely oral vowels produced with a lowered velum.
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 production of target oral and nasal vowels and simultaneously recording the acoustic signal, the predicted effects of velo-pharyngeal (VP) coupling on the acoustic output of the vocal tract can be separated from those due to oral articulatory configuration in a qualitative manner. Based on the previous research, all nasal vowels were expected to be produced with at least some change in lingual and labial articulatory configurations compared to their oral vowel counterparts. Evidence is observed which suggests that many of the oral articulatory configurations of NMF nasal vowels enhance the acoustic effect of VP coupling on F1 and F2 frequencies. Moreover, evidence is observed that the oral articulatory strategies used to produce the oral/nasal vowel distinction are idiosyncratic, but that, nevertheless, speakers produce a similar acoustic output. These results are discussed in the light of motor equivalence as well as the view that the goal of speech acts is acoustic, not articulatory.
•Articulatory and acoustic data from 12 French speakers' oral/nasal vowel productions.•The predicted effects of nasalization and oral articulation are separated.•Oral articulations of the nasal vowels enhance the effect of nasalization on F1/F2.•Speakers use idiosyncratic articulatory strategies to reach a similar acoustic output.•Results support the view that the goal of speech acts is acoustic, not articulatory.
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 contexts exhibit nasalization throughout the entirety of the vowel interval, and we propose that a similar co-articulatory realization previously acted to resist diachronic change in this environment; (2) anticipatory vowel nasalization is nearly as extensive as carryover vowel nasalization, which is contrary to previous claims; and (3) the degree of vowel nasalization in word-initial contexts is relatively high, even in the #_C environment, suggesting that the sound change *#Na > #a has involved the loss of the oral constriction associated with N but not the complete loss of the velum gesture.
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