Day 55 of 150 Language Difficulty 5/10
Categorical perception sharpens phoneme boundaries
Quick answer
Categorical perception sharpens phoneme boundaries. Today's question (Categorical perception of phonemes) asks about a finding from Liberman, A. M., Harris, K. S., Hoffman, H. S., & Griffith, B. C. in 1957. The correct option is Three discrete phoneme categories with sharp boundaries — full explanation, primary source, and glossary cross-links below.
Today's question
Liberman et al. (1957) showed that synthetic speech sounds varying continuously between /b/, /d/, and /g/ are perceived not as a smooth continuum but as:
Reveal the answer and explanation
Correct: B — Three discrete phoneme categories with sharp boundaries
Liberman, Harris, Hoffman & Griffith presented synthesised syllables varying along the second-formant transition that distinguishes /b/, /d/, and /g/. Discrimination across category boundaries was excellent; discrimination of equally-spaced acoustic differences within a category was near chance. The pattern — high between-category sensitivity, low within-category sensitivity — defines categorical perception. Originally claimed as speech-specific, follow-up work showed analogous patterns for trained non-speech sounds and music, suggesting a general perceptual-learning mechanism.
About the source
Liberman, A. M., Harris, K. S., Hoffman, H. S., & Griffith, B. C. (1957). The discrimination of speech sounds within and across phoneme boundaries. Journal of Experimental Psychology, 54(5), 358–368.
Every Cognition Bible question cites a primary source — a paper, book chapter, or monograph that exists, that we can point to on Google Scholar, and whose finding the question accurately summarizes. No fabricated authority strings, no name-drops without paper-level grounding.
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