Acoustic and articulatory correlates of stop consonants in a parrot and a human subject

General acoustic patterns in productions of American English stops /p,b,t,d,k,g/ by a Grey parrot (Psittacus erithacus) and his primary human trainer are identified. Comparisons demonstrated both differences (coherence of voicing [/p,t,k/ and /b,d,g/] and place [/p,b/, /t,d/, and /k,g/] subsets, predictive power of measures related to F1 and F3) and similarities (categorical distinctions among stop consonants) in acoustic properties of psittacine and human speech. The authors suggest how acoustic data might be correlated with articulatory events in the parrot. Our data are also compared with speech from a mynah (Gracula religiosa). Because humans perceive and correctly label psittacine stop consonants despite differences in avian and human articulatory and acoustic parameters, our findings (a) further expand our initial work with vowels [Patterson and Pepperberg, J. Acoust. Soc. Am. 96, 634-648 (1994)], (b) corroborate findings suggesting that the perceptual discontinuities exploited by speech may be accessible to various sensory systems, and (c) challenge the notion that human speech production is a unique process.