Inferring causes during speech perception.

Area of Science:

• Cognitive Science
• Psycholinguistics
• Speech Perception

Background:

• Speech perception faces the challenge of talker variability (lack of invariance).
• Listeners adapt to this variability, but the causes of atypical pronunciations are often ambiguous.
• Previous models suggested ambiguous causal evidence is ignored in speech adaptation.

Purpose of the Study:

• To investigate how listeners infer causes of atypical pronunciations.
• To examine the role of causal inference in speech adaptation.
• To understand how speech perception manages uncertainty about pronunciation causes.

Main Methods:

• Three experiments were conducted to test listener adaptation.
• Participants were exposed to atypical pronunciations with varying causal ambiguity.
• Adaptation levels were measured based on perceived pronunciation characteristics (characteristic vs. incidental).

Main Results:

• Speech adaptation was significantly affected by whether atypical pronunciations were perceived as characteristic or incidental.
• Listeners retained information from causally ambiguous pronunciations.
• Previously experienced ambiguous evidence influenced subsequent adaptation after causal disambiguation.

Conclusions:

• Causal inference plays a crucial role in speech perception and adaptation.
• The speech perception system actively uses ambiguous evidence, contrary to previous proposals.
• Listeners can integrate new evidence to resolve ambiguity and guide adaptation processes.