1
|
Tuninetti A, Chládková K, Peter V, Schiller NO, Escudero P. When speaker identity is unavoidable: Neural processing of speaker identity cues in natural speech. BRAIN AND LANGUAGE 2017; 174:42-49. [PMID: 28715718 DOI: 10.1016/j.bandl.2017.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/02/2017] [Indexed: 06/07/2023]
Abstract
Speech sound acoustic properties vary largely across speakers and accents. When perceiving speech, adult listeners normally disregard non-linguistic variation caused by speaker or accent differences, in order to comprehend the linguistic message, e.g. to correctly identify a speech sound or a word. Here we tested whether the process of normalizing speaker and accent differences, facilitating the recognition of linguistic information, is found at the level of neural processing, and whether it is modulated by the listeners' native language. In a multi-deviant oddball paradigm, native and nonnative speakers of Dutch were exposed to naturally-produced Dutch vowels varying in speaker, sex, accent, and phoneme identity. Unexpectedly, the analysis of mismatch negativity (MMN) amplitudes elicited by each type of change shows a large degree of early perceptual sensitivity to non-linguistic cues. This finding on perception of naturally-produced stimuli contrasts with previous studies examining the perception of synthetic stimuli wherein adult listeners automatically disregard acoustic cues to speaker identity. The present finding bears relevance to speech normalization theories, suggesting that at an unattended level of processing, listeners are indeed sensitive to changes in fundamental frequency in natural speech tokens.
Collapse
Affiliation(s)
- Alba Tuninetti
- MARCS Institute for Brain, Behaviour, & Development, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; ARC Centre of Excellence for the Dynamics of Language, Canberra, ACT, Australia.
| | - Kateřina Chládková
- Amsterdam Center for Language and Communication, University of Amsterdam, Spuistraat 134, 1012VB Amsterdam, The Netherlands; Cognitive and Biological Psychology, Institute of Psychology, University of Leipzig, Neumarkt 9-19, 04109 Leipzig, Germany.
| | - Varghese Peter
- MARCS Institute for Brain, Behaviour, & Development, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; ARC Centre of Excellence for the Dynamics of Language, Canberra, ACT, Australia.
| | - Niels O Schiller
- Leiden University Centre for Linguistics, Faculty of Humanities, Leiden University, Van Wijkplaats 4, P.O. Box 9515, 2300 RA Leiden, The Netherlands; Leiden Institute for Brain & Cognition, c/o LUMC, Postzone C2-S, P.O. Box 9600, 2300 RC Leiden, The Netherlands.
| | - Paola Escudero
- MARCS Institute for Brain, Behaviour, & Development, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; ARC Centre of Excellence for the Dynamics of Language, Canberra, ACT, Australia.
| |
Collapse
|
2
|
Mulak KE, Bonn CD, Chládková K, Aslin RN, Escudero P. Indexical and linguistic processing by 12-month-olds: Discrimination of speaker, accent and vowel differences. PLoS One 2017; 12:e0176762. [PMID: 28520762 PMCID: PMC5435166 DOI: 10.1371/journal.pone.0176762] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 04/17/2017] [Indexed: 11/19/2022] Open
Abstract
Infants preferentially discriminate between speech tokens that cross native category boundaries prior to acquiring a large receptive vocabulary, implying a major role for unsupervised distributional learning strategies in phoneme acquisition in the first year of life. Multiple sources of between-speaker variability contribute to children's language input and thus complicate the problem of distributional learning. Adults resolve this type of indexical variability by adjusting their speech processing for individual speakers. For infants to handle indexical variation in the same way, they must be sensitive to both linguistic and indexical cues. To assess infants' sensitivity to and relative weighting of indexical and linguistic cues, we familiarized 12-month-old infants to tokens of a vowel produced by one speaker, and tested their listening preference to trials containing a vowel category change produced by the same speaker (linguistic information), and the same vowel category produced by another speaker of the same or a different accent (indexical information). Infants noticed linguistic and indexical differences, suggesting that both are salient in infant speech processing. Future research should explore how infants weight these cues in a distributional learning context that contains both phonetic and indexical variation.
Collapse
Affiliation(s)
- Karen E. Mulak
- The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Penrith, New South Wales, Australia
- Australian Research Council Centre of Excellence for the Dynamics of Language, Western Sydney University, Penrith, New South Wales, Australia
| | - Cory D. Bonn
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York, United States of America
| | - Kateřina Chládková
- Amsterdam Center for Language and Communication, University of Amsterdam, Amsterdam, Netherlands
| | - Richard N. Aslin
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York, United States of America
| | - Paola Escudero
- The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Penrith, New South Wales, Australia
- Australian Research Council Centre of Excellence for the Dynamics of Language, Western Sydney University, Penrith, New South Wales, Australia
| |
Collapse
|