The dependency of binaural detection thresholds on interaural level differences was investigated. Detection thresholds were measured for four discrete tones with either 100, 500, 1000 or 2500 Hz presented in diotic, uniform exciting noise (N0) via headphones using an adaptive forced choice method. The sine tones were presented either in-phase (S0) or anti-phasic (Sπ), and the interaural level difference (ILD) of the tone was varied within 15 dB. Preliminary detection thresholds show that unmasking depends on the applied ILD. In the N0S0 condition, thresholds of low-frequency tones decrease by up to 8 dB for an ILD of 10 dB, which almost corresponds to the monaural threshold. This decrease with increasing ILD cannot be observed at 2500 Hz. In the N0Sπ condition, however, the increase in thresholds with increasing ILD is approximately equal for all frequencies. The resulting decrease in unmasking seems to follow the level decrease of the two summed anti-phasic ear signals with increasing ILD. In particular, the results of the N0Sπ condition suggest that the amount of binaural unmasking is more affected by the ILD than in the N0S0 condition.