International audienceA sound ~contralateral precursor! presented to the nontest ear prior to the onset of a masker andprobe has been shown to reduce the temporal effect in simultaneous masking with noise maskers butnot with tonal maskers. The present study examined this further. The probe was a 4.0-kHz tone. Inexperiment 1a, the masker was a 4.4-kHz tone and the precursor was a 4.4-kHz tone or anunmodulated ~UM! or amplitude-modulated ~AM! band of noise ~4.4–8.0 kHz!. In experiment 1b,the masker was a broadband noise and the precursor was a UM or an AM broadband noise. In bothexperiments the precursor consistently reduced the temporal effect for only one of the seven or eightsubjects, regardless of precursor type. These largely negative results indicate that it may not bepossible to use contralateral precursors to gain much insight into the mechanisms underlyingtemporal effects in simultaneous masking