The amplitude of the vertex potential (N1P2component) evoked by alternately presented sounds was studied as a function of the azimuth separation between the sound sources. A 1000‐ 67‐dB‐SPL tone served as the standard stimulus. It was located at 270° azimuth and was presented on every odd second throughout 200 sec. A variable stimulus of similar physical characteristics was presented on every even second. Its location, however, was either 270°, 315°, 0° or 90° azimuth. TwentySswere tested four times on each combination of standard stimulus‐variable stimulus location. The amplitude of the evoked responses summed for 100 standard and 100 variable stimuli differed significantly (p<0.01) among the various conditions of spatial separation. Response amplitudes were least when the sound sources were near one another. It is suggested that alternately presented stimuli originating close together in space activate a common pool one neurons, thereby promoting habituation. When alternately presented stimuli are widely separated in space, the stimuli from each location activate a different pool of neurons; the habituating effect of repetitive stimuli is reduced.