Duplex perception

Duplex perception refers to the linguistic phenomenon where "part of the acoustic signal is used for both a speech and a nonspeech percept." For example, an English statement voiced with rising pitch may be interpreted as a question about the statement's veracity.

Discovered by Rand (1974): A listener is presented with two simultaneous, dichotic stimuli. One ear receives an isolated third-formant transition that sounds like a nonspeech chirp. At the same time the other ear receives a base syllable. This base syllable consists of the first two formants, complete with formant transitions, and the third formant without a transition. • The listener’s percept is duplex, that is, the completed syllable is perceived and the nonspeech chirp is heard at the same time