Early versus Extended Exposure in Speech Perception Learning: Evidence from Switched-Dominance Bilinguals

Area of Science:

• Psycholinguistics
• Cognitive Science
• Speech and Hearing Science

Background:

• Language learning outcomes are influenced by the timing and amount of language exposure.
• Bilinguals' language proficiency and dominance can impact speech recognition.
• Understanding speech in challenging auditory environments is crucial for effective communication.

Purpose of the Study:

• To compare speech recognition accuracy in English and Spanish across different listener groups.
• To investigate the effects of language order, dominance, and listening conditions on word recognition.
• To determine the benefits and limitations of early language exposure on bilingual speech processing.

Main Methods:

• Assessed sentence-final word recognition accuracy in English and Spanish.
• Included three listener groups: Spanish heritage speakers (SHS), L1-dominant English/Spanish learners, and L1-dominant Spanish/English learners.
• Varied listening conditions: signal-to-noise ratio (SNR), sentence predictability, and speech style (clear vs. plain).

Main Results:

• SHS demonstrated English recognition accuracy equivalent to L1-dominant English speakers.
• SHS showed significantly lower Spanish recognition accuracy compared to L1-dominant Spanish speakers.
• SHS benefited from easier listening conditions but were more affected by noise and low predictability in their non-dominant Spanish (L1) than dominant English (L2).

Conclusions:

• Early language exposure provides benefits but also has limitations on speech recognition.
• L2-dominant heritage speakers exhibit L1-like recognition in their dominant language and better non-dominant language recognition than late L2 learners.
• Subtle differences in speech recognition accuracy between heritage speakers and monolingual listeners emerge under difficult listening conditions.