The present study examined the center and size of naïve adult listeners' vowel perceptual space (VPS) in relation to listener language (LL) and talker age (TA). Adult listeners of three different first languages, American English, Greek, and Korean, categorized and rated the goodness of different vowels produced by 2-year-olds and 5-year-olds and adult speakers of those languages, and speakers of Cantonese and Japanese. The center (i.e., mean first and second formant frequencies (F1 and F2)) and size (i.e., area in the F1/F2 space) of VPSs that were categorized either into /a/, /i/, or /u/ were calculated for each LL and TA group. All center and size calculations were weighted by the goodness rating of each stimulus. The F1 and F2 values of the vowel category (VC) centers differed significantly by LL and TA. These effects were qualitatively different for the three vowel categories: English listeners had different /a/ and /u/ centers than Greek and Korean listeners. The size of VPSs did not differ significantly by LL, but did differ by TA and VCs: Greek and Korean listeners had larger vowel spaces when perceiving vowels produced by 2-year-olds than by 5-year-olds or adults, and English listeners had larger vowel spaces for /a/ than /i/ or /u/. Findings indicate that vowel perceptual categories of listeners varied by the nature of their native vowel system, and were sensitive to TA.
Keywords: Cross-linguistic study; child speech; vowel perception.