A left-lateralized, near-vertex negativity in EEG, occurring 200–300 ms after stimulus onset, distinguishes sine-wave speech tokens perceived as speech from those perceived as noise, even when task-irrelevant. This response, interpreted as a phonological perceptual awareness negativity, was absent for frequency-flipped control tokens never perceived as speech. The P3b component was enhanced only for tokens both perceived as speech and task-relevant. The findings suggest that neural correlates of conscious perception, across different types of conscious content, are most likely midlatency negative-going brain responses in content-specific sensory areas.
A roadmap for studying conscious auditory perception is outlined, emphasizing how conscious experience emerges in complex auditory scenes. The authors argue that most research on the neural basis of conscious perception has come from vision, raising questions about generalizability. They discuss the functional role of the auditory system, identify phenomena that a theory of conscious auditory perception must explain, survey candidate neural correlates from existing literature, and consider implications for a general theory of conscious perception. Outstanding questions and recommended approaches and techniques for addressing them are also presented.