The impact of multi-accent input on children’s perceptual adaptation to L2 vowels

Monika Kučerová, Kateřina Chládková

Exposure to non-standard English varieties

1.453 billion speakers of English worldwide, more than a billion are non-native speakers [1]
Czech learners often exposed to General British/American English along with Czech English
How does multi-accent exposure affect adaptation to a novel accent in the short term?

[1] Eberhard, D. M., Simons, G. F., & Fennig, C. D. (2024). Ethnologue: Languages of the World (27th ed.). SIL International.

Hi, together with Katka Chladkova, we are looking at L2 vowel adaptation by 5 to 6 year olds who were learning English in a non-immersive setting.

there are almost 1.5 billion englis hspeakers worldwide. more than a billion of those are actually non native speakers. it is often the case that english learners are exposed to both native and non native talkers. this seems to be a common scenario for czech learners of english: they are often exposed to native accented english and czech accented english.

it seems to be a common scenario that czech children who are learning english are exposed to both czech english and some form of native english. we wanted to know how this multi accent exposure, as opposed to exposure to a single accent, affects adaptation to novel accents. but we looked at short term effects of multi vs mono accent exposure.

L1 and L2 adaptation

Adaptation: altering cue-to-category mappings to recognize linguistic units
Adults adapt to a novel L1 accent within minutes [2], changes in categorization last [3]
Two year olds recognize words in a novel L1 accent [4, 5, 6]
Two year olds raised with multi-accent input also adapt fast to novel speakers [7]
8 year-olds adapt to words in a novel L2 accent (even presentation of single unlabeled words) [8]

[2] Bradlow, A. R., & Bent, T. (2008). Perceptual adaptation to non-native speech.

[3] Eisner, F., & McQueen, J. M. (2006). Perceptual learning in speech: Stability over time.

[4] Cooper, A., Paquette-Smith, M., Bordignon, C., & Johnson, E. K. (2023). The influence of accent distance on perceptual adaptation in toddlers and adults.

[5] Best, C. T., Tyler, M. D., Gooding, T. N., Orlando, C. B., & Quann, C. A. (2009). Development of phonological constancy: Toddlers’ perception of nativeand jamaican-accented words.

[6] Creel, S. C. (2012). Phonological similarity and mutual exclusivity: On-line recognition of atypical pronunciations in 3–5-year-olds.

[7] van der Feest, S. V., & Johnson, E. K. (2016). Input-driven differences in toddlers’ perception of a disappearing phonological contrast.

[8] Hu, C.-F. (2021). Adaptation to an unfamiliar accent by child l2 listeners.

Adaptation mechanisms

General criterion relaxing (GCR): increasing category variability, increasing likelihood of input forms mapping onto lexical representations [9]
Targeted shifts adaptation: only adjusting mappings for which evidence is observed [10]
GCR and targeted shifts are not mutually exclusive

[9] Schmale, R., Seidl, A., & Cristia, A. (2015). Mechanisms underlying accent accommodation in early word learning: Evidence for general expansion.

[10] White, K. S., & Aslin, R. N. (2011). Adaptation to novel accents by toddlers.

This study

Does short-term exposure to multi-accent input facilitate adaptation to an unfamiliar L2 accent?
Are reactions to pairs of dissimilar words and minimal pairs modulated by short term accent exposure?
Target contrast: GBE /ɛ/-/æ/

Method

51 Czech children aged 4;11 to 6;11
Experience with EFL

Conditions (between-subject): 4 training videos narrated by
1. two Czech talkers speaking English (condition CE),
2. two General British English talkers (condition GBE),
3. one Czech and one GBE talker (Multi-accent condition)

Method

Test video with one Singapore English talker, one White South African English talker
3 training videos at home, 1 training video in the lab, test video in the lab
Lab: tablet, headphones (some without)

Input from GBE talkers

Input from Czech talkers

Test input: SE talker, WSAE talker

Word identification task

2AFC sound selection
Dissimilar words contrasted in consonants
Minimal pairs contrasted in /ɛ, æ/
3 MPs at test: berry-Barry, bread-Brad, Jan-Jen;
Test: 3 filler trials; 5 MP trials
Each talker provided one word on each trial
MPs presented in two types of trials: contrastive and homophones

Method: Word identification

https://monikakucerova.github.io/exp_final/pres.html

Results: word identification

glmer(correct ~ cond * pair_type + progress + (1 | participant_id) + (1 | pair)

Results: sound replays

replay ~ cond ∗ stim + progress + (1 | participant_id) + (1 | pair)

Relative probability of replaying sounds on the word identification task
Multi children may replay dissimilar words more than MPs, GBE and CE groups show a different pattern

Discussion

The CE group identified MPs produced as homophones above chance?

Acoustic analyses: no reliable differences between the stimuli (point and dynamic measurements of F1, F2, F3, f0, duration)
BUT few word tokens used in the task
Combination of cues not uncovered by analysis; exemplar-based word representation + interlanguage benefit -> recognition based on stored idiosyncrasies

[12] Hayes-Harb, R., Smith, B. L., Bent, T., & Bradlow, A. R. (2008). The interlanguage speech intelligibility benefit for native speakers of Mandarin: Production and perception of English word-final voicing contrasts. Journal of phonetics.

Equivalence classification (EC)

Except for CE at training, no group demonstrated above chance identification on MP trials
Participants have not yet acquired the difficult contrast despite L2 experience
EC: sounds that signal distinct categories are perceptually collapsed into one [14, 17]

[14] Kuhl, P. K. (2004). Early language acquisition: Cracking the speech code. Nature reviews neuroscience, 5(11), 831–843.

[17] Flege, J. E. (1995). Second language speech learning: Theory, findings, and problems. Speech perception and linguistic experience: Issues in cross-language research

Are GCR and EC different mechanisms?

GCR: increasing probability of word recognition by widening speech sound categories [9]
Mapping incoming sound tokens that indicate different categories onto a single category; high minimal pair confusability
Are variable categories the result of GCR adaptation or EC?
Underspecified L1 lexical representations -> adaptation using GCR
Underspecified L2 lexical representations -> processing using EC

[9] Schmale, R., Seidl, A., & Cristia, A. (2015). Mechanisms underlying accent accommodation in early word learning: Evidence for general expansion. Developmental science, 18(4), 664–670.

General criterion relaxing and learning

Binary learning outcomes tied to EC, gradient adaptation
Increasing category variability is also adaptive
A variable L1-reused category in the L2 can indicate learning, even if this strategy may lead to minimal pair confusability
No differences between groups in identification, but there were differences in sound replays

Summary

After relatively short term exposure, participants learned to identify L2 words, but only if they were sufficiently dissimilar
Participants did not successfully identify minimal pair members that differed in a difficult vowel; number of varieties they were exposed to in the short term was not shown to affect identification
Established categories determine extent of adaptation, insufficient experience -> high MP confusability [15, 16]
Multi-accent input lead to higher probability of replaying dissimilar words over MPs than mono-accent input
Parallels between GCR adaptation and EC

[15] Kemp, N., Scott, J., Bernhardt, B. M., Johnson, C. E., Siegel, L. S., & Werker, J. F. (2017). Minimal pair word learning and vocabulary size: Links with later language skills.

[16] Llompart, M. (2021). Phonetic categorization ability and vocabulary size contribute to the encoding of difficult second-language phonological contrasts into the lexicon. Bilingualism: Language and Cognition

References

[1] Eberhard, D. M., Simons, G. F., & Fennig, C. D. (2024). Ethnologue: Languages of the World (27th ed.). SIL International. http://www.ethnologue.com.

[2] Bradlow, A. R., & Bent, T. (2008). Perceptual adaptation to non-native speech. Cognition, 106(2), 707–729.

[3] Eisner, F., & McQueen, J. M. (2006). Perceptual learning in speech: Stability over time. The Journal of the Acoustical Society of America, 119(4), 1950–1953.

[4] Cooper, A., Paquette-Smith, M., Bordignon, C., & Johnson, E. K. (2023). The influence of accent distance on perceptual adaptation in toddlers and adults. Language Learning and Development, 19(1), 74–94

[5] Best, C. T., Tyler, M. D., Gooding, T. N., Orlando, C. B., & Quann, C. A. (2009). Development of phonological constancy: Toddlers’ perception of nativeand jamaican-accented words. Psychological science, 20(5), 539–542.

[6] Creel, S. C. (2012). Phonological similarity and mutual exclusivity: On-line recognition of atypical pronunciations in 3–5-year-olds. Developmental Science, 15(5), 697–713

[7] van der Feest, S. V., & Johnson, E. K. (2016). Input-driven differences in toddlers’ perception of a disappearing phonological contrast. Language Acquisition, 23(2), 89–111.

[8] Hu, C.-F. (2021). Adaptation to an unfamiliar accent by child l2 listeners. Language and Speech, 64(3), 491–514

References

[9] Schmale, R., Seidl, A., & Cristia, A. (2015). Mechanisms underlying accent accommodation in early word learning: Evidence for general expansion. Developmental science, 18(4), 664–670.

[10] White, K. S., & Aslin, R. N. (2011). Adaptation to novel accents by toddlers. Developmental science, 14(2), 372–384.

[11] Zelazo, P. D. (2006). The Dimensional Change Card Sort (DCCS): A method of assessing executive function in children. Nature protocols, 1(1), 297-301.

[13] Llompart, M., & Reinisch, E. (2019). Robustness of phonolexical representations relates to phonetic flexibility for difficult second language sound contrasts. Bilingualism: Language and Cognition, 22(5), 1085–1100.

[14] Kuhl, P. K. (2004). Early language acquisition: Cracking the speech code. Nature reviews neuroscience, 5(11), 831–843.

[15] Kemp, N., Scott, J., Bernhardt, B. M., Johnson, C. E., Siegel, L. S., & Werker, J. F. (2017). Minimal pair word learning and vocabulary size: Links with later language skills. Applied Psycholinguistics, 38(2), 289–314.

[17] Flege, J. E. (1995). Second language speech learning: Theory, findings, and problems. Speech perception and linguistic experience: Issues in cross-language research, 92(1), 233-277.

Eskerrik asko! Děkujeme! Thank you!

kucerova@psu.cas.cz

Category boundary task

Category boundary task with stimuli ranging from b[ɛ]rry to b[æ]rry
Later omitted (repetitive, demanding)

Results: category boundary task

22 children completed; later omitted