Introduction 1990 1980 1989 1993 1994 1999 1999 2000 2001 1999 2001 2003 2003 2003 2004 2005 2006 1999 2003 2006 Here we asked what happens if the sounds that capture the onset of the lights are assigned to a stream of other sounds with which they form a well-formed sequence. If auditory grouping takes priority over intersensory pairing, one expects an improvement on the visual TOJ task only if the capture sounds segregate from the auditory stream. Alternatively, though, audio–visual pairing might take priority over auditory grouping in which case observers should improve on the visual TOJ task no matter whether the sounds segregate or not. 2000 2001 Experiment 1: Capture and flanker sounds with the same or different frequency 1 Fig. 1 a grey ovals b  Method Participants Stimuli 2 1 Design Procedure Results and discussion Z 1964 1 Table 1 Mean just noticeable differences (JND) in ms, and standard errors of the mean (in parentheses) of Experiment 1 and 2   Flanker sounds Same as capture sounds Different from capture sounds Experiment  AV-interval (ms) JND TVE JND TVE Exp 1 (Frequency) 0 21.0 (0.8) 0.5 22.1 (1.1) 3.8* 100 20.5 (1.1)  18.3 (0.7)  Exp 2 (Rhythm) 0 29.1 (2.5) −3.7 23.9 (1.9) 3.6* 100 32.8 (2.5)  20.3 (0.8)  Capture Sounds Presented at ∼0 or ∼100 ms audio–visual intervals; flanker Sounds with the same or different frequency (Exp 1) or rhythm (Exp 2) as capture sounds. The temporal ventriloquist effect (TVE) is the improvement in JND between the ∼0 and ∼100 ms audio–visual intervals P P F P t  t P t P Experiment 2: Capture and flanker sounds with the same or different rhythm 1990 Method Participants Stimuli and design Results and discussion P F P t  t P t P Experiment 3: Capture and flanker sounds from the same or different location 1990 2006 The notion that sound location matters for auditory grouping, but not for intersensory pairing also lead to a very counter-intuitive prediction. In case flanker sounds were presented near the central lights, there should more temporal ventriloquism by capture sounds presented from a lateral position than from central position, because only the lateral sounds segregate. With central flankers, there should thus be more temporal ventriloquism when the location of the sounds and lights differ, rather then when they are the same. Method 1 Results F P 2 F P F P t P t P t P t P t P Table 2 Mean just noticeable differences (JND) in ms, and standard errors of the mean (in parentheses) of Experiment 3   Location of flanker sounds   Same as capture sounds Different from capture sounds Location of capture sounds AV-interval (ms) JND TVE JND TVE Central 0 28.2 (2.1) −0.9 27.7 (2.0) 3.9* 100 29.1 (2.3)  23.8 (1.4)  Lateral 0 30.0 (2.2) 1.7 29.0 (1.8) 3.1* 100 28.3 (2.0)  25.9 (1.8)  Capture Sounds Presented at ∼0 or ∼100 ms audio–visual intervals from central or lateral location; flanker sounds presented from the same or different location as the capture sounds. The temporal ventriloquist effect (TVE) is the improvement in JND between the ∼0 and ∼100 ms audio–visual intervals P General discussion This study examined how principles of auditory grouping relate to intersensory pairing. Two capture sounds that normally enhance performance on a visual TOJ task (i.e. temporal ventriloquism) were embedded in a sequence of flanker sounds which could differ in frequency (Exp. 1), rhythm (Exp. 2), or location (Exp. 3). In all experiments, we found that temporal ventriloquism only occurred when the capture sounds differed from the flankers, and there was thus no effect when flanker and capture sounds were the same. Presumably, when the capture sounds differ, they segregate from the auditory stream, and only then they can be paired cross-modally with the lights. When the two capture sounds do not differ from the flankers, they are perceptually grouped in an auditory stream, in which case they lose their saliency and cannot interact cross-modally anymore. 2000 2001 2004a b 1986 1994 1996 2001 2004 2006 2004 1992 2001