A cocktail party effect in the median plane?

Abstract

Recent research has been conducted on the effects of spatialized audio on a listener’s ability to detect and identify a target speech signal when presented among nontarget speech signals in the horizontal plane [W. T. Nelson et al., Proceedings of the 1998 IMAGE Conference (1998), pp. 159–166]. However, the existence of a ‘‘cocktail party effect’’ in the median plane has not been addressed. The purpose of the present investigation was to determine whether or not the spatial separation of multiple simultaneous speech sources in the median plane leads to improved detection and intelligibility. Independent variables include the number and angular separation of the speech signals, the sex of the target talker, and the presence or absence of head motion cues. All speech signals—phrases from a modified Coordinate Response Measure [T. J. Moore, AGARD Conference Proceedings 311: Aural Communication in Aviation (1981), pp. 2.1–2.6]—were digitally filtered via nonindividualized HRTFs and presented over headphones. Results will be compared with those obtained in the horizontal plane. Inplications for the design of auditory displays will be discussed.