Commentary: Revisiting vocal perception in non-human animals: a review of vowel discrimination, speaker voice recognition, and speaker normalization.

Abstract

Comparative research provides a unique window into our understanding of human vocal perception. We commend Kriengwatana, Escudero, and ten Cate (KEtC) for providing a much-needed review of this diverse literature. Their appraisal of three research areas highlights conceptual and empirical gaps, while also pointing to fruitful directions for future research. This commentary addresses the literature on asymmetries in vowel perception. In their review of this topic KEtC focus on vowel contrasts that have revealed directional asymmetries in infants and non-human animals. We offer some clarification with respect to these stimulus issues and highlight another aspect of this research landscape—the role of task demands—that must also guide future comparative investigations.