Impact of early bilingualism on perception and production of new sounds of a third language in young children

Abstract

Aims and objectives:

In this study, we examine the discrimination and the pronunciation of new Spanish and Mandarin phonemes in French–English bilingual children in first and second grades compared with French-speaking monolingual children of the same grades.

Design/methodology/approach:

We recruited 18 French–English bilingual children and 27 French-speaking monolingual children in first or second grade in elementary schools. They were asked to carry out discrimination and word repetition tasks from audio files recorded by a Colombian Spanish speaker and a Chinese Mandarin speaker.

Data and analysis:

For discrimination tasks, we calculated two measures: the percentage of success in the discrimination of two Spanish rhotics (/r/-/ɾ/) and the percentage of success in the discrimination of the set of Mandarin phonological contrasts (/p-p^h/, /t-t^h/, /k-k^h/, /ʂ-ɕ/, /ts-ts^h/, /tʂ-tʂ^h/ and /tɕ-tɕ^h/). For word repetition tasks, pronunciation was assessed for accuracy and foreign accent by native Spanish and Mandarin speakers. We completed our analyses with measures of voice onset time (VOT) values of Mandarin stops in word initial position (in milliseconds).

Findings and conclusions:

The results of our study showed that the members of the bilingual group were neither advantaged nor disadvantaged compared with the monolingual group. Our findings suggest that specific exposure to the characteristics intrinsic to an L3 is necessary for mastering new sounds in an L3.

Originality:

This study examines whether early bilingualism facilitates the perception and the pronunciation of new sounds in an L3 in young bilingual (French–English) children. Few studies have examined this issue in this age group, that is, 6- to 9-year-old children. In addition, unlike other studies that analyzed oral production in speech, we chose to focus on the pronunciation of sounds in isolated words.

Significance:

Our study highlights that no significant differences between bilingual and monolingual children were revealed. These results contribute to an understanding of whether there are bilingual advantages in L3 phonological acquisition.

Keywords

Early bilingualism phonetic discrimination oral production VOT third language

Introduction

Native speakers of a given language learn to apply phonological rules of their language from an early age. These skills are reflected both in recognition and production of sounds (Kuhl et al., 2006; Splendido, 2016). However, for L2 learners, the ability to perceive and produce L2 phonology is not a simple task because they gradually lose this ability as they age (Flege, 1995).

Acquiring a third language (L3) can constitute an even greater challenge. Over the past two decades, L3 learning has been recognized as a distinct phenomenon (Cabrelli, 2010). Its importance is increasingly recognized: for global citizens, the ability to speak several languages has become a desirable learning goal because of increasing job-related mobility, the popularity of foreign exchange programs, and the introduction of additional languages in the early stages of elementary education (Lejot, 2014; Troncy, 2021).

Despite advances in research on phonological acquisition in a second language, the effects of bilingualism or multilingualism on phonological competencies in each of the languages acquired by learners remain inconclusive. Some researchers (e.g., Antoniou et al., 2015; Kehoe & Havy, 2019; Kieseier, 2021; Lim et al., 2015) have concluded that bilingualism confers advantages in the discrimination and pronunciation of L3 segments, while others (e.g., Gallardo del Puerto, 2007; Werker, 1986) failed to find any significant effects. Among the studies that showed positive effects associated with bilingualism, some (e.g., Kehoe & Havy, 2019) demonstrated general bilingual advantages which they attributed to the fact that bilinguals had developed a more diverse set of learning strategies dedicated to the discrimination and pronunciation of language sounds. Other researchers (e.g., Wrembel et al., 2019) noted specific bilingual advantages, that is, simply linked to experiences with particular sounds. Kieseier (2021) suggested that there were general positive bilingual effects such as cognitive abilities, phonological awareness and lexical skills in bilingual children in each of their languages. Furthermore, findings of previous studies (Kopečková, 2016; Llama & Cardoso, 2018; Llama et al., 2010; Wrembel, 2010, 2011) revealed substantial interference in L3 sound pronunciation from learners’ L1 and L2. It is important to note that the majority of previous studies on the influence of L1 and L2 on L3 phonological acquisition have focused on learners who have already been exposed to an L3 (intermediate or advanced level) rather than those having limited or no skills in an L3. In addition, there are few studies that focus on the effects of bilingualism on L3 learning in children. Furthermore, children’s ages are an additional factor that needs to be considered, as effects may only be apparent within a constrained time period.

Background

Critical or sensitive period hypothesis

In applied linguistics, the critical or sensitive period hypothesis is defined as a period of maximal sensitivity to a language in the environment which allows optimal language learning (Abrahamsson et al., 2018; Hyltenstam & Abrahamsson, 2003; Long, 2013). The critical period hypothesis suggests native-like abilities are not attainable after a given age, while the notion of a sensitive period is a less restrictive version such that the decline may be gradual and ultimate attainment may vary. Lenneberg (1967), who was the first to argue for the existence of a critical period, suggested that the decline of sensitivity to learning a new language coincides with the loss of cerebral plasticity during puberty. Considerable research exists reporting that bilinguals who acquire an L2 during childhood seem to have an advantage in the pronunciation of L2 speech sounds compared with those who started after early childhood (Abrahamsson et al., 2018; Flege, 1991, 1995, 1999; Flege et al., 2006). Long (2013) suggested that this period of sensitivity to acquire native-like competence, especially for the phonology of a language, occurs between birth and approximately 6 or 7 years of age.

A question that arises in this regard is whether exposure to an L2 during the critical period might allow compensation for the later loss of sensitivity to non-native sounds, or that it might prolong the period of sensitivity. It appears that bilinguals aged from 3 to 6 years learn very early on to adopt the phonetic characteristics of sounds depending on the languages that they use (Splendido, 2016) and the question remains whether this ability applies to new sounds of a language to which they have not been exposed.

Perceptual skills

A number of researchers (Kuhl et al., 2006; Ramon-Casas et al., 2017) in the field of language development support the idea that speech sound formation in phonological categories is a process which begins from birth and that this trajectory depends on the languages to which infants are exposed. In numerous studies, monolingual infants have been found to possess the ability to discriminate the native sounds of their L1, which tend to be maintained or improved with the increasing exposure to this L1. From birth, monolingual babies are also able to perceive some non-native phonological contrasts but tend to lose this capacity within their first year of life (Kuhl et al., 2006; Werker et al., 1981; Werker & Tees, 1983), a phenomenon known as perceptual narrowing.

Many authors (Ramon-Casas et al., 2017) have defended the idea that bilingual children need to go through a process of perceptual adjustment specific to bilingual language development. The trajectory of perceptual phonological development of young bilingual children appears to vary depending on the amount of exposure to each of their two languages (Ramon-Casas et al., 2017, 2023). During development, bilingual children need to reorganize the sounds that they hear in their two languages to be able to distinguish them.

As for L3 phonological development, Werker (1986) discovered that bilingual and trilingual adults were not better able than monolingual adults in discriminating the phonological contrasts / t/-/ʈ/ of Hindi and /k/-/q/ of an Amerindian language which are not used in their usual languages; this suggests that specific experiences with the sounds of a new language are necessary to be able to perceive them. However, Beach et al. (2001) showed a favorable effect of bilingualism in the discrimination of the Thai phonological contrast /b/-/p/-/p^h/ in Greek–English bilingual adults from Australia compared with monolingual English speakers. Even though bilingual speakers performed worse than Thai monolingual speakers, they were better than monolingual English speakers, probably due to the fact that the stop /p/ exists in the Greek phonological inventory.

In the study by Gallardo del Puerto (2007), the degree of bilingualism did not significantly influence the auditory discrimination of English foreign sounds (L3) in Spanish (L1)-Basque (L2) bilingual teenagers aged 9 to 18 years old attending schools in Spain in which the language of instruction is Basque. The strong bilinguals (having received about 9.5 years of exposure to Basque) had results similar to weak bilinguals (having received about 3 years of exposure to Basque) in the discrimination of English foreign sounds, regardless of the age of acquisition of L3 (4, 8 or 11 years old).

The findings of Patihis et al. (2015) suggest that a bilingual or trilingual advantage only occurs when there are specific phonetic similarities between the new language and the known languages, and not that there is a general bilingual or multilingual favorable effect. In their study, the sample included Spanish (L1)–English (L2) and English-Armenian bilingual adults as well as trilingual adults (some with at least one of their three languages that possess an aspirated stop contrast and others with languages that do not contain the contrast). The performances in auditory discrimination of Korean phonological contrasts /b/-/p/-/p^h/, /d/-/t/-/t^h/ and /g/-/k/-/k^h/ were analyzed. The number of languages mastered by the participants was positively correlated with their performances, but this correlation became insignificant with the exclusion of participants mastering at least one language distinguishing aspirated and non-aspirated stops. This suggested that the advantage depends on specific experiences with particular sounds, not on number of languages mastered.

Wrembel et al (2019) found that an advanced level in an L2 allowed German (L1)–English (L2) bilingual teenagers to perceive Polish (L3) phonological contrasts (/i/, /ɨ/, /ɛ/, /a/, /ɔ/, /u/, /ʂ-ɕ/, /t͡ʂ-t͡ɕ/, /ʐ-ʑ/, /d͡ʐ-d͡ʑ/). However, they noticed that specific experiences with particular speech sounds also contributed to maintaining this skill. The speakers who had had exposure to Polish (two subgroups: exposure to Polish from a single parent without much practice of the language, or inheritance of Polish as a second L1) performed better than those who had received no exposure in Polish before lessons at school.

The focus seems to have been on adults and teenagers, but much less on children. However, there are some studies supporting the idea that bilingual children have an increased openness to nonnative contrasts, that is, that perceptual narrowing is delayed. Using a functional near-infrared spectroscopy (fNIRS), Petitto et al. (2012) found that at 12 months, bilingual infants (English and another language unrelated to Hindi) were still sensitive to Hindi dental/retroflex contrasts, unlike English monolingual infants. Similarly, in an experiment carried out with 14- and 19-month-olds, Graf Estes and Hay (2015) demonstrated that at 19 months, bilingual infants (English and another nontonal language) were still able to discriminate Mandarin lexical tone contrasts in a context of word learning, while English monolingual infants had lost this ability at the same age. Furthermore, Singh et al. (2017) noted that English-Mandarin 11-month-old infants perceived the Hindi nonnative contrast /t/-/ʈ/, which the monolingual infants were unable to do at the same age. Singh (2018) demonstrated that at 18 months of age, Mandarin–English bilingual infants were sensitive to nonnative African click contrasts in novel words, unlike English monolingual infants. In an experiment carried out with 14- to 19-month-old infants, Singh and Tan (2021) discovered that in a context of novel word learning, English monolingual infants had already lost at 19 months their capacity to discriminate the Hindi nonnative contrast /t/-/ʈ/, which the English-Mandarin bilinguals were still able to do at the same age. However, bilingual 24-month-old infants had lost this perceptual skill. In a study with 10-year-old children (Salomé et al., 2021) results revealed a bilingual advantage in learning L3 vocabulary, with classroom-immersion children outperforming their monolingual peers on two of the three experimental tasks, namely forced-choice recognition and an auditive recognition task. These findings support the idea that bilinguals have an advantage in learning novel phonological forms.

In sum, the capacity to discriminate foreign phonological contrasts in an L3 had already been lost when teenagers and adults were tested. However, during the first two years of life, there is evidence that the loss of the ability to perceive nonnative contrasts is delayed in bilingual infants. According to theoretical models such as Flege’s speech learning model (e.g., Flege, 1995) and Best’s perceptual assimilation model (PAM) (e.g., Best, 1995), the perceptual adjustment process continues with the integration of a new phonological system as one progresses in each language (L1, L2, L3, etc.). There is a continuous shaping of the categorization of speech sounds as one receives linguistic information from the environment.

Pronunciation skills

Around the age of two, children usually begin to combine words. Along with lexical (receptive and expressive vocabulary), morphological, syntactic and metalinguistic development, this is a crucial step in the development of the phonological system, that is, the production of speech sounds. Researchers (Keffala et al., 2020; Kehoe & Girardier, 2020; Kehoe & Havy, 2019) have demonstrated that receptive and expressive vocabularies in the L1 and the L2 have considerable influence on any bilingual effects of phonological awareness in each of a bilingual’s languages, which is why it is important to analyze not only phonological discrimination aptitudes, but also pronunciation skills.

The phonological competences in each of a bilingual’s languages continue to evolve differently from monolinguals because of interlinguistic interactions. The acquisition rate of speech sounds of each language and the nature of interactions between the two phonological systems also vary from one bilingual to another depending of the quantity of exposure, characteristics inherent to their L1 and to their L2, as well as to the speech heard in the environment (Kehoe et al., 2004; Kehoe & Havy, 2019). Transfer, acceleration and delay effects during acquisition have often been reported (Kehoe & Kopisch, 2018). Moreover, differentiation and interaction combinations between L1 and L2 phonetic and phonological characteristics have frequently been reported (Kehoe & Kannathasan, 2021; Yang, 2021).

As for L3 phonological acquisition, Lim et al. (2015) observed that Mandarin–English–Malay trilingual children aged from 2.5 to 4.5 years old were faster than monolingual and bilingual children of the same age group in acquiring the set of sounds of phonological inventories in each of their three languages when they compared their results with those of other studies (Badrulzaman et al., 1999; Dodd et al., 2003; Norhaizan, 2005; Zhu, 2006).

In contrast, in word and syllable reading tasks, Gabriel et al. (2016) found that Mandarin-German bilingual teenagers (14 to 18 years old) were neither advantaged nor disadvantaged in the pronunciation of French stops /d/ and /t/, a language they did not know, in comparison with Mandarin and German monolingual speakers aged from 15 to 21 years old who were learning French as an L2.

The influence of previously acquired languages on Spanish rhotics production (the trill /r/ and the tap /ɾ/) was observed in the study by Kopečková (2016) conducted with German children aged 11 or 12 who had been learning English (L2) for at least 3 years and who were learning Spanish (L3). Some of the L3 learners were familiar with an additional language (Croatian, Israeli Hebrew, Italian and Polish, Russian, or Spanish as a heritage language). Following an analysis of auditory and acoustic characteristics of Spanish rhotic productions, the multilingual learners who had frequent contacts with Spanish and English inside and outside school demonstrated more precision in the articulation of the Spanish rhotics than occasional users of these two languages (contacts with English and Spanish only at school). This advantage was also influenced by the degree of similarity between the phonological inventories of the previously acquired languages and Spanish. For example, the bilinguals who had another L1 that possesses the trill /r/, which is generally more complicated to produce than the tap /ɾ/, showed an advantage compared with other bilinguals, which indicated that specific learning experience is necessary to allow the assimilation of certain phonetic characteristics that are generally complex to articulate.

Reyes et al. (2017) examined how previous linguistic experience and universal strategies guide phonological acquisition in school classrooms. Specifically, they focused on potential advantages of bilingualism in 4- to 8-year-old children who were either monolingual English speakers or bilingual Korean–English speakers. Thirty-four children carried out a picture naming task. The results indicated that, in general, the children easily acquired a native-like pronunciation of a Spanish rhotic sound, but that Korean–English bilinguals outperformed English L1 children. The researchers suggested that even though previous linguistic knowledge plays a role in L2 and L3 acquisition, the bilingual children were able to overcome transfer mistakes because they were guided by universal developmental strategies from the first stages of acquisition since their metalinguistic competencies were more developed compared with those of the monolinguals.

A bilingual advantage was suggested by Kieseier (2021) in a study on learning the set of English (L3) sounds in German bilingual children in 4th grade (having another L1 at home) controlling other factors (e.g., vocabulary skills, cognitive functions and phonological awareness in German and English). Even though German monolinguals outperformed German bilinguals in vocabulary, cognitive functions and phonological awareness, the bilinguals did just as well in the English pronunciation tasks. These results indicated that, unlike monolinguals, the bilinguals were not as dependent as monolinguals on relying on their lexical knowledge to successfully pronounce L3 sounds. With their multilingual experiences, these learners showed increased universal strategies and knowledge, which contributed to their L3 production skills.

As revealed in a number of the previously discussed studies, simple bilingualism alone is not always enough in itself to allow proficiency in the pronunciation of new sounds; specific exposure to the L3 may be necessary to allow accurate pronunciation and assimilate the native accent. Learning to articulate new phonemes may require practice in the L3 despite bilingual competency.

However, other studies (e.g., Kieseier, 2021; Reyes et al., 2017) report that bilingual children appear to have an advantage in new sound production compared with monolinguals. Early exposure to two languages, as is the case for simultaneous bilinguals, may counteract the effects of the critical or sensitive period. Strategies developed during the critical period due to bilingual exposure and use may allow enhanced abilities compared with monolinguals without that extra linguistic experience. Our study seeks to shed light on this issue.

The current study

The literature review leads us to formulate the following specific research questions:

Research Question 1 (RQ1). Are French–English bilingual children better able to discriminate Spanish and Mandarin sounds than monolingual French-speaking children?

Research Question 2 (RQ2). Are French–English bilingual children better able to imitate the pronunciation of foreign Spanish and Mandarin sounds than monolingual French-speaking children?

(a) According to native Spanish and Mandarin listeners’ perception, do French–English bilingual children more accurately pronounce these sounds and with a more native-like accent than monolingual French-speaking children?

(b) Do French–English bilingual children produce Mandarin stops with a voice onset time (VOT) more compliant with native speaker standards than monolingual children?

Although a bilingual advantage in discrimination and pronunciation of L3 sounds has not always been reported in previous studies, the notions of critical or sensitive periods lead us to formulate the following hypotheses:

Hypothesis 1 (H1). Bilingual children will be better able than monolingual children in discriminating new Spanish and Mandarin sounds due to the fact that they have developed a more extended diversity of learning strategies devoted to language acquisition during the sensitive period (phonological awareness, metalinguistic competences).

Hypothesis 2 (H2). Bilingual children will have more accurate pronunciation of target sounds than monolingual children for the same reasons mentioned in the Hypothesis 1.

(a) According to native Spanish and Mandarin listeners’ perception, bilingual children should more accurately pronounce L3 sounds; similarly, they will be evaluated as having a weaker foreign accent than monolingual children.

(b) Bilingual children will produce Mandarin stops with VOT values more compliant with the native speaker standards.

Method

Participants

We recruited 45 participants aged between 6 and 9 years in first or second grade in elementary schools in the province of Quebec, in which French is the official language. The study was carried out in a region of the province with little exposure to English, compared with the more bilingual metropolis, Montreal. Participants included 18 French–English bilingual children and 27 monolingual French-speaking children, to compare their performances in perception and pronunciation of Spanish and Mandarin sounds that exist neither in French nor in English. The members of the bilingual group received simultaneous exposure to the L1 and the L2 between 0 and 5 years old largely due to their bilingual household, while those of the monolingual group received some exposure to English at school but this was limited to a few words or sentences. A background questionnaire allowed a determination of bilingual exposure.

Procedure

Our goal was to verify the influence of early bilingualism on the discrimination and the pronunciation of new sounds of an L3. The children carried out discrimination and pronunciation tasks of foreign Spanish and Mandarin sounds individually during a 30-min period.

Tasks

Discrimination tasks

Our method for the discrimination tasks was adapted from Werker (1986), Beach et al. (2001), Gallardo del Puerto (2007), Patihis et al. (2015), and de Antoniou et al. (2015).

Spanish

The children listened to series of Spanish words forming minimal pairs (distinguished by a single sound) recorded in an audio file by a male Colombian Spanish speaker. The phonological contrast targeted was the phonemic opposition between the two Spanish rhotics: the tap /ɾ/ and the trill /r/. The Spanish word list consisted of 12 series, including six that concerned the target contrast. The other six two-word series were distractors, which means that phonological Spanish contrasts also exist in French and in English with the aim of preventing participants from guessing the target Spanish contrast. The participants had to judge in each of the two-word series if the two words were the same or different. All the series were presented in the same order for each of the participants.

Mandarin

We created a list of seven two-word series containing the target Mandarin phonological contrasts (/p-p^h/, /t-t^h/, /k-k^h/, /ʂ-ɕ/, /ts-ts^h/, /tʂ-tʂ^h/ and /tɕ-tɕ^h/) spoken by a male Mandarin speaker. There was only one target phonological contrast in each series. The children had to carry out the same tasks as those administered in Spanish, except that the words were in Mandarin.

Word repetition tasks

The pronunciation tests were similar to those used by Beach et al. (2001) and Spinu et al. (2016) who administered pronunciation imitation tasks.

Spanish

In the Spanish word repetition task, the targeted phonemes were /ɾ/, /r/, /x/ and /ʎ/. The list consisted of two words for each of four target Spanish sounds. The other eight words served as distractors, words with sounds existing in both French and English. The participants listened to the Spanish words in an audio file recorded by the same Colombian Spanish speaker and they had to repeat aloud each of the words heard.

Mandarin

In the Mandarin word repetition task, the targeted sounds were the aspirated phonological contrasts of stops (/p-p^h/, /t-t^h/ and /k-k^h/) as well as the phonemes /ʂ/, /ɕ/, /ts^h/, /tʂ/, /tʂ^h/, /tɕ/ et /tɕ^h/. There was one word for each of the targeted Mandarin sounds. The participants listened to the Mandarin words in an audio file recorded by the same Mandarin speaker and they had to repeat aloud each of the words heard. We measured the VOT values for the Mandarin stops produced in initial position (/p/, /p^h/, /t/, /t^h/, /k/ and /k^h/). For the VOT, we examined Mandarin stops rather than Spanish stops since the former differ in important ways from the children’s L1, while the latter are similar to French stops.

Tasks of native speakers and listeners

Spanish and Mandarin word lists were pronounced and recorded by a male Colombian Spanish speaker and by a male Mandarin speaker. Two native listeners for each of the target languages (Spanish and Mandarin) listened to the children’s pronunciation recorded during the word repetition tasks and evaluated the target sounds for two aspects: accuracy and foreign accent.

Data analysis

The performances in discrimination tasks were measured by calculating and using the percentage correct response rate. We calculated and used the average percentage for each of the two groups for the performances on Spanish rhotics discrimination and Mandarin phonological contrasts.

For the word repetition tasks, the native listeners listened and evaluated the pronunciation of each targeted sound in words pronounced by each of the participants on a Likert-type scale of 1 to 5. They evaluated both sound accuracy (1: very difficult to understand; 5: very easy to understand) and the foreign accent level (1: no foreign accent; 5: a very strong foreign accent). This evaluation method was inspired by Lloyd-Smith et al. (2017), who asked listeners proficient in the participants’ target L3 (a language they did not know) to judge the level of foreign accent on a Likert-type scale. Similar procedures have been used with spontaneous discourse and with utterances (Crowther, 2020; Trofimovich et al., 2017). In our study, we calculated the global average for accuracy and foreign accent given by the two listeners for all the Spanish and Mandarin target sounds.

The software Praat was used to record the pronunciations of the children and to measure the VOT of each of the word-initial Mandarin stops produced for each of the participants. The exclusion criteria for VOT measurements were parasitic noise too intense for measurement and errors in stop pronunciation (either omissions or substitutions by other consonants).

Performances between the bilingual and monolingual groups for the two tasks were compared using one-way t-tests for independent samples (significance level: p ⩽ .05). When the Levene’s postulate of homogeneity of variances was respected, we reported Student’s statistics. Otherwise, we used Welch’s t-test. For the two groups, we compared the VOT average values for each of the languages used with the native speaker standards established by Lisker and Abramson (1964), Louër (2019) and Yue and Profita (2020).

Results

Success rate in discrimination tasks

Table 1 indicates data relating to discrimination of the two Spanish rhotics and the Mandarin phonological contrasts. First of all, we note that the average percentages of successful discrimination in Spanish (Monolingual group: Average = 14.2 %; Bilingual group: Average = 23.15 %) and Mandarin (Monolingual group: Average = 41.8 %; Bilingual group: Average = 41.27 %) are similar between the two groups, especially for Mandarin contrasts. Second, the results of Student’s unilateral t-test revealed a t(43) = -1.348, p = .092 > 0.05 for Spanish discrimination and those of Welch’s unilateral t-test give a t(23,457) = 0.069, p = .473 > 0.05 for Mandarin discrimination. Although differences for Spanish rhotics are more striking than those in Mandarin, no statistically significant difference between monolingual and bilingual children was found in the discrimination tasks.

Table 1.

Performances in discrimination tasks, t-test results.

Performances	Linguistic status	Average	Standard deviation	t-test	p =
Discrimination of Spanish rhotics	Monolinguals Bilinguals	14.20% 23.15%	20.52% 23.67%	Student : -1.348	0.092
Discrimination of Mandarin contrasts	Monolinguals Bilinguals	41.80% 41.27%	15.81% 29.76%	Welch : 0.069	0.473

Note. Significance level adopted p ⩽ 0.05.

Performance in pronunciation tasks

Accuracy and foreign accent as perceived by native listeners

Table 2 presents data on the evaluation of participants’ pronunciation by native listeners for two distinct aspects: accuracy and foreign accent. Overall averages in Spanish and Mandarin accuracy (Spanish = 3.56 in monolingual participants and 3.62 in bilingual participants; Mandarin: 3.84 for monolinguals and 3.77 for bilinguals) and foreign accent (Spanish = 2.51 for monolinguals and 2.62 for bilinguals) are similar between the two groups. For accuracy: t(43) = -0.384, p = .351 > 0.05 in the Spanish task and t(43) = 0.681, p = .25 > 0.05 in the Mandarin task. For foreign accent: t(43) = -0.49, p = .313 > 0.05 in Spanish and t(43) = -0.153, p = .44 > 0.05 in Mandarin. Therefore, there were no significant differences between the two groups for Spanish or Mandarin in terms of accuracy or accent evaluations.

Table 2.

Global performance in pronunciation of Spanish and Mandarin sounds, t-test results.

Performances	Linguistic status	Average (maximum 5)	Standard deviation	t-test	p =
Global accuracy of targeted Spanish sounds	Monolinguals	3.56	0.53	Student : -0.384	0.351
Global accuracy of targeted Spanish sounds	Bilinguals	3.62	0.61	Student : -0.384	0.351
Global foreign accent of targeted Spanish sounds	Monolinguals	2.51	0.68	Student : -0.49	0.313
Global foreign accent of targeted Spanish sounds	Bilinguals	2.62	0.81	Student : -0.49	0.313
Global accuracy of targeted Mandarin sounds	Monolinguals	3.84	0.29	Student : 0.681	0.25
Global accuracy of targeted Mandarin sounds	Bilinguals	3.77	0.42	Student : 0.681	0.25
Global foreign accent of targeted Mandarin sounds	Monolinguals	1.71	0.2	Student : -0.153	0.44
Global foreign accent of targeted Mandarin sounds	Bilinguals	1.72	0.23	Student : -0.153	0.44

Note. Significance level adopted p ⩽ 0.05.

VOT

The data analysis relating to the average VOT of the Mandarin stops is presented in Table 3. First of all, the averages in each of the two groups (monolinguals = 13.58 ms; bilinguals = 0.19 ms) reveals that both groups pronounced the Mandarin /p/ with a VOT within the native standards of non-aspirated stops established by Lisker and Abramson (1964), Louër (2019) and Yue and Profita (2020). However, the two groups produced the /t/ (monolinguals = 57.06 ms; bilinguals = 63.13 ms) and the /k/ (monolinguals = 64.98 ms; bilinguals = 70.23 ms) with a VOT that exceeded the upper limit of these native standards and that came close to the native standards for English voiceless stops. For the aspirated stops (/p^h/, /t^h/, /k^h/), both monolingual and bilingual participants did not reach the native speaker standards in Mandarin because the VOT varied between 45.14 ms and 91.04 ms. However, the VOT values were generally comparable with the native speaker standards of English voiceless stops. In sum, t-tests revealed that there was no statistically significant difference between the bilinguals and the monolinguals for all the unaspirated and aspirated stops examined (p > .05).

Table 3.

Mandarin stops pronounced by children according to t-tests and native speaker standards.

Stops	Linguistic status	Average VOT	Native standards	Standard deviation	Test t	p =
/p/	Monolinguals	13.58 ms	Between 0 and 40 ms	21.33 ms	Welch: 1.433	0.083
/p/	Bilinguals	0.19 ms	Between 0 and 40 ms	33.26 ms	Welch: 1.433	0.083
/p^h/	Monolinguals	71.66 ms	⩾100 ms	40.93 ms	Student : -0.411	0.342
/p^h/	Bilinguals	76.64 ms	⩾100 ms	36.61 ms	Student : -0.411	0.342
/t/	Monolinguals	57.06 ms	Between 0 and 40 ms	30.57 ms	Student : -0.502	0.310
/t/	Bilinguals	63.13 ms	Between 0 and 40 ms	42.01 ms	Student : -0.502	0.310
/t^h/	Monolinguals	45.14 ms	⩾100 ms	37.41 ms	Student : -0.961	0.171
/t^h/	Bilinguals	58.13 ms	⩾100 ms	49.92 ms	Student : -0.961	0.171
/k/	Monolinguals	64.98 ms	Between 0 and 40 ms	32.32 ms	Student : -0.465	0.323
/k/	Bilinguals	70.23 ms	Between 0 and 40 ms	31.47 ms	Student : -0.465	0.323
/k^h/	Monolinguals	91.04 ms	⩾100 ms	49.04 ms	Student : 1.080	0.143
/k^h/	Bilinguals	76.78 ms	⩾100 ms	28.34 ms	Student : 1.080	0.143

Note. Significance level adopted p ⩽ .05.

Discussion

Success rate in discrimination tasks

Our findings are similar to those found with regard to teenagers in the study by Gallardo del Puerto (2007) and in adults of the study by Werker (1986), Gallardo del Puerto (2007) and Patihis et al. (2015). These studies demonstrated no generalized effect of bilingualism and multilingualism in the discrimination of the phonological contrasts absent from the inventories of languages known by the participants. However, our results with children from six to nine years of age differ from those of studies involving infants and very young children in the studies of Petitto et al. (2012), Singh et al. (2017), Singh (2018), Singh and Tan (2021), and Graf Estes and Hay (2015). Participant age is likely to be a crucial factor leading to result differences across studies.

One explanation for the weak performances in the two groups of participants for the Spanish rhotics discrimination may be due to a possible assimilation to the French rhotic /ʁ/, which means that /r/ and /ɾ/ were perceived as two possible allophones of the phoneme /ʁ/ as in French, the L1 of the participants.

As for the discrimination errors in Mandarin, these could be attributed to the following assimilations: 1) /p/-/p^h/, /t/-/t^h/, /k/-/k^h/: assimilation of each pair of plosives as two allophonic variants of the plosives /p/, /t/, /k/; 2) /tʂ/-/tʂ^h/, /tɕ/-/tɕ^h/: assimilation of the phonemes /tʂ/, /tʂ^h/, /tɕ/ and /tɕ^h/ as four allophonic variants of the affricate /tʃ/; 3) /ʂ/-/ɕ/: assimilation of the phonemes /ʂ/ and /ɕ/ as two allophonic variants of the fricative /ʃ/; 4) /ts/-/ts^h/: assimilation of these two phonemes as being two equivalents to the allophonic affricate variant [t_s] of the phoneme /t/ in Quebec French. In this regard, Chen and Han (2019) and Chen and Tian (2021) revealed that Cantonese (L1)–English (L2)–Mandarin (L3) multilingual adult learners similarly tended to confuse the set of Mandarin spirants (/ts/, /ts^h/, /s/, /tɕ/, /tɕ^h/, /ɕ/, /tʂ/, /tʂ^h/ et /ʂ/).

In light of the participants’ performances, we cannot affirm that early bilingualism necessarily creates an effect of prolonging the sensitive period. The results suggest that the decline in sensitivity to foreign sounds of a new language in the 6- to 9-year-old children in our study was already underway, since members of both groups displayed, on average, a success rate lower than 50% in the discrimination of the new phonemic Spanish and Mandarin contrasts. Therefore, our first hypothesis in which we stated that bilinguals should be better than monolinguals in discriminating the targeted phonological contrasts of these two L3 has not been supported.

Performance in pronunciation tasks

Accuracy and foreign accent perceived by native listeners

Our results on accuracy and foreign accent perception are consistent with the conclusions drawn by Gabriel et al. (2016), who found non-significant differences on the foreign accent rating between bilinguals and monolinguals aged 14 to 21. However, our results contrast with the findings of Reyes et al. (2017), who observed a general bilingual advantage in children aged 4 to 8 years in the pronunciation of Spanish rhotics. As for Kieseier’s study (2021), we cannot compare our results with those of the 4^th grade children in this study, since we did not examine the role of lexical skills, cognitive functions and phonological awareness in the performance of the members of our sample. Regarding the sounds of Mandarin, most participants’ pronunciations of the plosives were perceived by the native listeners either as the targets, as their aspirated or unaspirated counterparts, or as being in an intermediate position. Just as in the study of Chen and Han (2019) and Chen and Tian (2021), confusion between spirants (/ts/, /ts^h/, /s/, /tɕ/, /tɕ^h/, /ɕ /, /tʂ/, /tʂ^h/, and /ʂ/) was observed.

These results therefore do not provide support for Hypothesis 2a according to which bilinguals would pronounce the foreign sounds of the two L3s more accurately, and with a weaker foreign accent according to the perception of native listeners, compared with the monolingual children.

VOT

With regard to the pronunciation of Mandarin stops, these pronunciations were perceived by the native speaker evaluators as either the target sounds or their aspirated or unaspirated counterparts, that is, intermediate sounds between the two, in both the bilingual and monolingual groups These perceptions on the part of native listeners are consistent with the fact that the average VOT of Mandarin plosives in both groups was midway between the native norms for unaspirated Mandarin plosives and those for aspirated Mandarin plosives, and this, both for unaspirated sounds and for those which were supposed to be aspirated. As members of both groups also tended to produce aspirated features in their pronunciation of unaspirated stops, they may have integrated the unaspirated ([p], [t], [k]) and aspirated ([p^h], [t^h], [k^h]) as allophonic variants of the voiceless stops already heard in their L1 and their L2. The results therefore do not support Hypothesis 2b according to which bilingual children produce VOT values more compliant with native speaker standards.

With regard to results from both the discrimination and production tasks, we can note again that members of our monolingual group had received some exposure to the L2 (predominantly in English classes at school); as a result, we are unable to say whether that minimal exposure to the L2 affected the results between groups.

In sum, this study, revealing no significant differences in perception and production of new sounds between bilingual and monolingual young school children, provides additional evidence for theoretical proposals that suggest there are early maturational constraints for these aspects of language acquisition.

Conclusion

In the present study, we analyzed the influence of early bilingualism on perception and pronunciation of new sounds of an L3 in first- and second-grade children (aged 6–9 years) in Quebec. According to our analyses, French–English bilingual children were neither advantaged nor disadvantaged compared with French L1 monolingual children. No significant differences were found in discrimination and pronunciation tasks carried out in Spanish and Mandarin. These results did not confirm the idea that early bilingual acquisition would allow compensation for the loss of sensitivity to new sounds of an L3 associated with maturational constraints as might be suggested by the notion of a critical or sensitive period. In contrast, they support the fact that the ability to discriminate and pronounce new sounds of an L3 require specific prolonged exposure to phonetic and phonological proprieties of this new language, regardless of bilingual status. However, the members of our monolingual group had had some exposure to the L2 although the extent to which that may have affected performances is unknown. Future research in this area should include a larger sample with a monolingual group without having had any exposure to the L2, add tasks including items from other languages, and collect measures over time in a longitudinal design.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iDs

Noémie Germain

Kirsten M. Hummel

Author biographies

Noémie Germain completed a master’s thesis at Laval University on which this article is based: ‘‘L’influence du bilinguisme précoce sur la perception et la production des sons d’une langue étrangère chez les enfants de 1re et de 2e année du primaire.’’

Kirsten M. Hummel is a professor of applied linguistics at Laval University. Her areas of specialization are second language acquisition and bilingualism.

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