[1] Pfizer Global Res & Dev, Clin Technol, Voice Acoust Lab, Groton, CT USA
[2] Univ Connecticut, Dept Commun Sci, Storrs, CT 06269 USA
[3] Univ Connecticut, Dept Psychol, Storrs, CT 06269 USA
[4] Pfizer Global Res & dev, CNS Clin Dev, New London, CT USA
[5] Univ Quebec, Ctr Neurosci Cognit, Dept Psychol, Montreal, PQ H3C 3P8, Canada