Generation of speech continua through monaural fusion

A procedure based on monaural fusion has been developed to construct acoustic continua between natural speech sounds, to be used in studies of speech perception. Two speech stimuli of similar temporal structure and different spectral composition are precisely aligned in time and presented simultaneously to the listener. By mixing both stimulus components in varying intensity ratios, a transition from one component to the other can be achieved. Such stimulus continua have several advantages over the synthetic continua commonly used in studies of categorical perception and related phenomena: They are based on real speech stimuli; the endpoint stimuli are unambiguous; and the stimuli are characterized by a well-defined physical variable, the relative intensity of the two components.