Binaural frequency difference limens in noise were obtained under homophasic and antiphasic conditions. Signal frequencies of 200, 300, 500, 700, and 1000 Hz were investigated at 5- and 10-dB sensation levels while 500 Hz was also explored at 15, 20, and 25 dB. The masker was a bandlimited noise with a spectrum level of 55 dB. Results indicate significant changes in discrimination behavior as a function of phase condition and sensation level. Alternative interpretations of the data are considered.