Electrophysiological Evidence of Early Cortical Sensitivity to Human Conspecific Mimic Voice as a Distinct Category of Natural Sound.

Purpose From an anthropological perspective of hominin communication, the human auditory system likely evolved to enable special sensitivity to sounds produced by the vocal tracts of human conspecifics whether attended or passively heard. While numerous electrophysiological studies have used stereotypical human-produced verbal (speech voice and singing voice) and nonverbal vocalizations to identify human voice-sensitive responses, controversy remains as to when (and where) processing of acoustic signal attributes characteristic of "human voiceness" per se initiate in the brain. Method To explore this, we used animal vocalizations and human-mimicked versions of those calls ("mimic voice") to examine late auditory evoked potential responses in humans.

Forward masking in the superior paraolivary nucleus of the rat.

In natural acoustic environments, perception of acoustic stimuli depends on the recent contextual history. Forward masking describes a phenomenon whereby the detection threshold of a probe stimulus is markedly increased when it is preceded by a masking stimulus. The aim of this study was to characterize the offset response of single units in the superior paraolivary nucleus (SPON) to a forward masking paradigm.