Catherine T Best

• PhD
• Chair at Western Sydney University

The classical view is that perceptual attunement to the native language, which emerges by 6-10 months, developmentally precedes phonological feature abstraction abilities. That assumption is challenged by findings from adults adopted into a new language environment at 3-5 months that imply they had already formed phonological feature abstractions a...

Bilingualism and the study of speech sounds are two of the largest areas of inquiry in linguistics. This Handbook sits at the intersection of these fields, providing a comprehensive overview of the most recent, cutting-edge work on the sound systems of adult and child bilinguals. Bringing together contributions from an international team of world-l...

Parent-infant interactions highlight the role of parental input, considering both the quality, infant-directed speech, and quantity of interactions, adult words and communicative turns, in these interactions. However, communication is bidirectional, yet little is known about the infant's role in these interactions. This study (n = 35 4-month-old in...

Infants can abstract amodal information about place of articulation at 4-5 months, before perceptual attunement to native consonants occurs (Altuntas et al., in preparation). We tested infants in the same task at 10 months, after native consonant attunement has commenced, which may affect phonological abstraction relative to 4–5 months. 29 infants...

Unlike tone languages such as Mandarin, English lacks tones at the sub-lexical level. Accordingly, English listeners have difficulty perceptually assimilating tones as categorized or uncategorized native segments (Perceptual Assimilation Model, PAM: Best, 1995). While English listeners can categorize the four lexical tones of Mandarin, i.e., level...

Relative to their adult-directed speech (ADS), mothers expand the triangle circumscribed by the reference vowels (/i a u/) in F1/F2 space when interacting with their infants. This vowel space expansion in infant-directed speech (IDS) is thought to support word learning and phonological development. But what about non-reference (i.e., 'central') vow...

We examined how accent variability during training on minimal-tone-contrast Mandarin words affects English listeners' subsequent generalization of tone categorization and discrimination to new talkers and accents. English listeners underwent 6 days of training on 16 pseudowords (4 tones × 4 sets) produced by 12 talkers of either Beijing (n = 24) or...

English learners have difficulties using tones in Mandarin words [1]. As high phonetic variability facilitates second language (L2) word learning [2], we investigated how L2-Mandarin accent variability in minimal-tone-contrast word training affects Mandarin -naïve English participants' tone-word learning. 48 English learners completed 6 training se...

Adults learn non-native phonological contrasts faster if they experience the stimulus language in their first postnatal 6 months than if they never experienced it [1]. The resulting implication that young infants engage in phonological abstraction was examined here. We trained infants to associate words from two artificial mini-languages distinguis...

This paper characterizes the perceptual structure of vowel systems in five regional accents of English, from Australia (A), New Zealand (Z), London (L), Yorkshire (Y), and Newcastle upon Tyne (N), on the basis of “whole system” vowel categorization experiments. We established patterns of within-accent vowel confusions, and then explored cross-accen...

The present study examined how native phonological and phonetic factors in non-native speech perception (Perceptual Assimilation Model [PAM]: Best, 1995) affect non-native imitation of Thai tones by Thai-naïve Mandarin and Vietnamese participants, and how memory load and stimulus variability shift the balance between phonological versus phonetic mo...

The present study examined native language phonological and phonetic factors in non-native lexical tone perception by tone language listeners, manipulating memory load and stimulus variability to bias listeners towards a more phonological or more phonetic mode of perception. Mandarin and Vietnamese listeners categorised the five Thai lexical tones...

Mandarin-naïve English listeners have difficulties categorizing the four lexical tones that distinguish word meanings in Mandarin. This study investigated how L2-Mandarin regional accent variability in training on minimal-tone-contrast words affected tone perception. Prior to training, although listeners accurately categorized and discriminated ris...

Background: Speaking depends on refined control of jaw opening and closing movements. The medial pterygoid muscle (MPT), involved in jaw closing, and the lateral pterygoid muscle (LPT), involved in jaw opening, are two key mandibular muscles in mastication and are likely to be recruited for controlled movements in speech. Objectives: Three hypot...

The four lexical tones of standard Beijing Mandarin (henceforth, Mandarin), i.e., level, rising, dipping, and falling, are produced with regional accents by speakers from other regions of China. This study investigated how native Beijing listeners categorize and rate second language (L2) Mandarin tones produced by Yantai, Shanghai, and Guangzhou sp...

Poster presented at Speech Prosody 2022 for the paper titled Native Beijing listeners' perceptual assimilation of Mandarin lexical tones produced by L2-Mandarin speakers from Yantai, Shanghai, and Guangzhou.

We present and describe the Italian Roots in Australian Soil (IRIAS) speech corpus. Following a sociophonetic approach, our aim is to extend and complement the frequently investigated macro-structures of lexical, syntactic and morphological interactions among immigrants’ languages and common sociolinguistic investigations about immigrants’ language...

Purpose: The Australian English Communicative Development Inventory (OZI) is a 558-item parent report tool for assessing language development at 12–30 months. Here, we introduce the short form (OZI-SF), a 100-item, picture-supported, online instrument with substantially lower time and literacy demands. Method: In tool development (Study 1), 95 item...

No PDF available ABSTRACT Pronunciations of Beijing Mandarin are those of Standard Mandarin (hereafter Mandarin), which developed from the Beijing dialect. Native speakers of other regional dialects in China learn Mandarin as an early second language, and produce its four lexical tones (level, rising, dipping, and falling) with regional accents. Th...

Native listener judgements and acoustic comparisons are sensitive to deviations between non-native speech and native productions, but both have drawbacks and are inefficient for evaluating large databases. To probe whether Support Vector Machines (SVM) might offer an efficient alternative, we used three SVM models trained with native Thai lexical t...

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 study tests whether Australian English (AusE) and European Spanish (ES) listeners differ in their categorisation and discrimination of Brazilian Portuguese (BP) vowels. In particular, we investigate two theoretically relevant measures of vowel category overlap (acoustic vs. perceptual categorisation) as predictors of non-native discrimination...

Second language speech learning is affected by learners' native language backgrounds. Teachers can facilitate learning by tailoring their pedagogy to cater for unique difficulties induced by native language interference. The present study employed Support Vector Machine (SVM) models to simulate how naïve listeners of diverse tone languages will ass...

A cross tone-language perceptual assimilation study investigated native categorisations and goodness ratings of non-native Thai tones by Thai-naive listeners differing in their native tone systems: Mandarin, Northern Vietnamese and Southern Vietnamese. We derived hypotheses from the Perceptual Assimilation Model (PAM: Best, 1995), which considers b...

The present study investigated tone variations in regionally accented Mandarin (i.e., Standard Mandarin [SM] spoken by dialectal Chinese speakers) as influenced by the varying tone systems of their native dialects. 12 female speakers, four each from Guangzhou, Shanghai and Yantai, were recruited to produce monosyllabic words in SM that included min...

No PDF available ABSTRACT This study investigated tone variations in regionally accented Mandarin (i.e., Standard Mandarin [SM] spoken by native speakers of other regional dialects in China). Yantai, Shanghai, and Guangzhou dialects were selected because their tone systems are different in various ways from the Beijing dialect, which is the basis o...

No PDF available ABSTRACT Non-native tone production and imitation have been found to be phonetically deviant from native production for some discrete measures. However, it remains unresolved whether non-native imitation differs from native production in terms of the differentiation of tones in acoustic tone space. 32 native Mandarin speakers who h...

Listeners often experience cocktail-party situations, encountering multiple ongoing conversations while tracking just one. Capturing the words spoken under such conditions requires selective attention and processing, which involves using phonetic details to discern phonological structure. How do bilinguals accomplish this in L1-L2 competition? We a...

Bilinguals differ from monolinguals in the development of speech perception [1], word learning [2] and language discrimination [3]. In light of this, we investigated whether early bilingual experience influences the development of cross-accent word recognition. We tested monolingual and bilingual 17-month-olds' recognition of familiar words spoken...

No PDF available ABSTRACT Much evidence has accrued indicating that language experience from infancy shapes our categorization and discrimination of consonants and vowels, differentiating perception of native versus non-native speech contrasts. The Perceptual Assimilation (PAM: Best), Speech Learning (SLM: Flege), Native Language Magnet (NLM: Kuhl)...

Memory load and task-irrelevant phonetic variations influence discrimination of non-native segmental contrasts. We tested how these factors modulate perceptual assimilation and/or discrimination of non-native lexical tone contrasts, relative to Perceptual Assimilation Model (PAM) [1-2] predictions. When perceptually assimilating Thai tones to their...

Native speakers of Japanese experience challenges in differentiating Mandarin nasal finals, even after years of experience with Mandarin. We used a hybrid perceptual training approach with highly proficient Japanese learners of Mandarin to improve their ability to distinguish nasal final contrasts, which are not distinctive in Japanese. Eight learn...

Analytical tools from Information Theory were used to quantify behaviour in cross-accent vowel perception by Australian, London, New Zealand, Yorkshire and Newcastle UK listeners. Results show that Australian listeners impose expected patterns of perceptual similarity from their own accent experience on unfamiliar accents, regardless of the actual...

Background Children from refugee backgrounds are less likely to access appropriate health and social care than non-refugee children. Our aim was to identify refugee children’s health/wellbeing strengths and needs, and the barriers and enablers to accessing services while preparing for primary and secondary school, in a low socio-economic multicultu...

This study explores the influences of listeners' native tone inventory on cross-language tone perception. Mandarin, Northern Vietnamese and Southern Vietnamese listeners (n = 13 per group; naive to Thai) categorised Thai tones into their native tone categories. Results show that all three groups categorised most Thai tones into their native tone ca...

Despite the fact that tone languages account for 70% of the languages in the world (Yip, 2002), studies have concentrated on only a few tone languages, such as Mandarin, Cantonese and Thai. There is a need to study a broader range of tone systems across languages, especially for Southeast Asian languages that are richer in contour tones. One reason...

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...

Non-native vowels perceived as speech-like but not identified with a particular native (L1) vowel are assimilated as uncategorised, and have received very little empirical attention. According to the Perceptual Assimilation Model (PAM: Best, 1995), contrasts where one or both phones are uncategorised are Uncategorised-Categorised and Uncategorised-...

Moroccan Arabic uses geminate/singleton contrasts in medial position but it is controversial whether it maintains them utterance-initially. To address this issue, we made simultaneous ultrasound and acoustic recordings of five native speakers producing target words containing /t/-/tt/ and /d/-/dd/ contrasts utterance-initially and -medially, 10 tim...

In two categorization experiments using phonotactically legal nonce words, we tested Australian English listeners’ perception of all vowels in their own accent as well as in four less familiar regional varieties of English which differ in how their vowel realizations diverge from Australian English: London, Yorkshire, Newcastle (UK), and New Zealan...

Most languages use lexical tone to discriminate the meanings of words. There has been recent interest in tracking the development of tone categories during infancy. These studies have focused largely on monolingual infants learning either a tone language or a non-tone language. It remains to be seen how bilingual infants learning one tone language...

Since the 1970s much has been learned about infant speech perception, particularly regarding developmental changes in perception of native versus non-native consonant and vowel contrasts and the growth of spoken word recognition. This chapter summarizes major theoretical models on how language experience influences infant speech perception, and on...

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...

This study investigates how second language (L2) listeners match an unexpected accented form to their stored form of a word. The phonetic-to-lexical mapping for L2 as compared to L1 regional varieties was examined with early and late Italian-L2 speakers who were all L1-Australian English speakers. AXB discrimination and lexical decision tasks were...

The perception of non-native speech is influenced by prior attunement to the native language. Evidence from auditory–only (AO) citation speech research indicates that non-native consonants are perceptually assimilated to native language categories, often causing difficulties in discrimination of non-native speech contrasts. But, as auditory-visual...

A single-item shadowing task was conducted to determine how identification of London-accented words by Australian listeners is affected by perceptual assimilation. This was evaluated in conjunction with two other well-established effects on word recognition: word frequency and talker variability. The results replicate frequency and talker variabili...

Experience, attitudes, and expectations have been identified as separate influences on speech perception and comprehension across groups. In this study, we investigate the interaction among these three variables. 58 Australia-born participants completed an online survey and a vowel categorization task. The survey examined participants’ experience w...

Substantial research has established that place of articulation of stop consonants (labial, alveolar, velar) are reliably differentiated using a number of acoustic measures such as closure duration, voice onset time (VOT), and spectral measures such as centre of gravity and the relative energy distribution in the mid-to-high spectral range of the b...

To become language users, infants must embrace the integrality of speech perception and production. That they do so, and quite rapidly, is implied by the native-language attunement they achieve in each domain by 6–12 months. Yet research has most often addressed one or the other domain, rarely how they interrelate. Moreover, mainstream assumptions...

In a discrimination experiment on several Tashlhiyt Berber singleton-geminate contrasts, we find that French listeners encounter substantial difficulty compared to native speakers. Native listeners of Tashlhiyt perform near ceiling level on all contrasts. French listeners perform better on final contrasts such as fit-fitt than initial contrasts suc...

This study examined three ways that perception of non-native phones may be uncategorized relative to native (L1) categories: focalized (predominantly similar to a single L1 category), clustered (similar to > 2 L1 categories), and dispersed (not similar to any L1 categories). In an online study, Egyptian Arabic speakers residing in Egypt categorized...

Native speech perception is generally assumed to be highly efficient and accurate. Very little research has, however, directly examined the limitations of native perception, especially for contrasts that are only minimally differentiated acoustically and articulatorily. Here, we demonstrate that native speech perception may indeed be more difficult...

A core issue in speech perception and word recognition research is the nature of information perceivers use to identify spoken utterances across indexical variations in their phonetic details, such as talker and accent differences. Separately, a crucial question in audiovisual research is the nature of information perceivers use to recognize phonet...

To probe how episodic and abstract processes contribute to flexible perception of phonetically variable speech, we evaluated Australian (Aus) listeners' perception of Aus-accented vowels versus those of an unfamiliar accent: Newcastle UK (Ncl). Aus listeners first heard a round-robin story told by multiple talkers of Aus or Ncl, then categorized mu...

Auditory speech is difficult to discern in degraded listening conditions, however the addition of visual speech can improve perception. The Perceptual Assimilation Model (Best, 1995) suggests that non-native contrasts involving a native phonological difference (two-category assimilation) should be discriminated more accurately than those involving...

This study proposes a method of superimposing a physical palatal profile, extracted from a speaker's maxillary impression, onto real-time mid-sagittal articulatory data. A palatal/dental profile is first obtained by three-dimensional–scanning the maxillary impression of the speaker. Then a high resolution mid-sagittal palatal line, extracted from t...

Co-collection and co-registration of ultrasound images of the tongue and articulometry data requires the stabilization of the ultrasound probe relative to the head using a non-metallic system. Audio, ultrasound, and articulometry data were recorded from 11 North American English speakers reading 10 blocks of 25 sentences, speaking for 2 minutes at...

Discriminating between certain non-native contrasts can be difficult. The Perceptual Assimilation Model [1] predicts that when two non-native phones are assimilated to the same native language category, as equally good or poor versions, discrimination should be poor (a single-category assimilation). However, it is not known to what extent visual an...

This study explores how experience with native language (L1) diphthongs influences the assimilation of non-native diphthongs. To obtain a comprehensive understanding of L1 attunement, native Australian English (AusE) speakers categorized and rated the Danish diphthongs, in addition to the monophthongs, in relation to their entire native vowel inven...

We will discuss the maintenance of the heritage dialect coronal fricatives in the speech of Italian-Australian trilinguals (dialect/Italian/English) originating from North Veneto, Italy, as compared to the variability found in the productions of comparable Italian-Australian trilinguals originating from Central Veneto. Results on coronal fricatives...

Using Best's (1995) perceptual assimilation model (PAM), we investigated auditory-visual (AV), auditory-only (AO), and visual-only (VO) perception of Thai tones. Mandarin and Cantonese (tone-language) speakers were asked to categorize Thai tones according to their own native tone categories, and Australian English (non-tone-language) speakers to ca...

A computational modeling study was conducted using multinomial logistic regression to predict whether exposure to an unfamiliar regional accent of English would influence vowel categorization in (1) the exposure accent, (2) the native accent, and (3) another unfamiliar accent. We manipulated the number of talkers in the exposure data to determine w...

We evaluated how Australian listeners perceive consonants spoken in two unfamiliar accents of English (Cockney, Yorkshire) and how consonant perception is influenced by short-term exposure to those accents. Results indicate that Australians misperceive some consonants from these accents and that short-term pre-exposure to them actually leads to fur...

There are obvious differences between recognizing faces and recognizing spoken words or phonemes that might suggest development of each capability requires different skills. Recognizing faces and perceiving spoken language, however, are in key senses extremely similar endeavors. Both perceptual processes are based on richly variable, yet highly str...

Although infants perceptually attune to native vowels and consonants well before 12 months, at 13–15 months, they have difficulty learning to associate novel words that differ by their initial consonant (e.g., BIN and DIN) to their visual referents. However, this difficulty may not apply to all minimal pair novel words. While Canadian English (CE)...

Research on language-specific tuning in speech perception has focused mainly on consonants, while that on non-native vowel perception has failed to address whether the same principles apply. Therefore, non-native vowel perception was investigated here in light of relevant theoretical models: the Perceptual Assimilation Model (PAM) and the Natural R...

This study examined how native speakers of Australian English, and French, non-tone languages with different rhythmic properties, perceived Mandarin tones in a sentence environment, according to their native prosodic categories. Results showed that both English and French speakers perceptually categorized Mandarin tones into their native intonation...

In this paper, we quantify the time-varying coordination of articulator motion for two speakers engaged in two face-to-face speaking tasks: repetition of simultaneously produced words (and word-pairs) and conversation. Correlation map analysis is used to compute the time-varying, correlation between pairs of signals for all possible pairings of sig...

The perceptual assimilation model (PAM; Best, C. T. [1995]. A direct realist view of cross-language speech perception. In W. Strange (Ed.), Speech perception and linguistic experience: Issues in cross-language research (pp. 171-204). Baltimore, MD: York Press.) accounts for developmental patterns of speech contrast discrimination by proposing that...

Perceptual attunement to native speech begins early in life, and becomes the foundation for adults’ rapid, accurate processing of native words and phrases. At the same time, native attunement imposes constraints on perception of many, though far from all, consonant and vowel contrasts that are irrelevant to native lexical distinctions. What is less...

Among the defining features of autism are delays and deficits in language and communication. However, the exact nature of these problems is unclear; language outcomes vary greatly, e.g., some children never acquire speech, others acquire only limited speech and yet others, despite early delays, acquire language within the normal range. Little is kn...

In this paper, we quantify the time-varying coordination of articulator motion for two speakers engaged in two face-to-face speaking tasks: repetition of simultaneously produced words (and word-pairs) and conversation. Correlation map analysis is used to compute the time-varying, instantaneous correlation between pairs of signals for all possible p...

By 12 months, children grasp that a phonetic change to a word can change its identity (phonological distinctive- ness). However, they must also grasp that some phonetic changes do not (phonological constancy). To test development of phonological constancy, sixteen 15-month-olds and sixteen 19-month-olds completed an eye-tracking task that tracked t...

Adult second language (L2) learners often have difficulty perceiving and producing L2 speech segments with native-like accuracy. The Speech Learning Model (SLM; Flege 1995) attributes this to perceptual distance between native (L1) and L2 segments, the Perceptual Assimilation Model (PAM; Best 1995; Best and Tyler 2007) to L1 assimilation of L2 segm...

Listeners' musical perception is influenced by cues that can be stored in short-term memory (e.g., within the same musical piece) or long-term memory (e.g., based on one's own musical culture). The present study tested how these cues (referred to as, respectively, proximal and distal cues) influence the perception of music from an unfamiliar cultur...