Volume 71, Issue 3

This study presents a comparative analysis of F1 and F2 vowel frequencies from Pijal Media Lengua (PML) and Imbabura Quichua. Mixed-effects models are used to test Spanish-derived high and low vowels against their Quichua-derived counterparts for statistical significance. Spanish-derived and Quichua-derived high vowels are also tested against Spanish-derived mid vowels. This analysis suggests that PML may be manipulating as many as eight vowels where Spanishderived high and low vowels coexist as near-mergers with their Quichua-derived counterparts, while high and mid vowels coexist with partial overlap. Quichua, traditionally viewed as a three-vowel system, shows similar results and may be manipulating as many as six vowels.

Applying the ‘end-state comfort' hypothesis of Rosenbaum et al. [J Exp Psych Learn Mem Cogn 1992;18:1058; Acta Psychol (Amst) 1996;94:59] to tongue motion provides evidence of long-distance subphonemic planning in speech. Speakers' tongue postures may anticipate upcoming speech up to three segments, two syllables, and a morpheme or word boundary later. We used M-mode ultrasound imaging to measure the direction of tongue tip/blade movements for known variants of flap/tap allophones of North American English /t/ and /d/. Results show that speakers produce different flap variants early in words or word sequences so as to facilitate the kinematic needs of flap/tap or other /r/ variants that appear later in the word or word sequence. Similar results were also observed across word boundaries, indicating that this is not a lexical effect.

The current study explores the question of how an auditory category is learned by having school-age listeners learn to categorize speech not in terms of linguistic categories, but instead in terms of talker categories (i.e., who is talking). Findings from visual-category learning indicate that working memory skills affect learning, but the literature is equivocal: sometimes better working memory is advantageous, and sometimes not. The current study examined the role of different components of working memory to test which component skills benefit, and which hinder, learning talker categories. Results revealed that the short-term storage component positively predicted learning, but that the Central Executive and Episodic Buffer negatively predicted learning. As with visual categories, better working memory is not always an advantage.