We present an interactive sound spatialization and synthesis system based on Interaural Time Difference (ITD) model and Evolutionary Computation. We define a Sonic Localization Field using sound attenuation and ITD azimuth angle parameters and, in order to control an adaptive algorithm, we used pairs of these parameters as Spatial Sound Genotypes (SSG). They are extracted from waveforms which are considered individuals of a Population Set. A user-interface receives input from a generic gesture interface (such as a NIME device) and interprets them as ITD cues. Trajectories provided by these signals are used as Target Sets of an evolutionary algorithm. A Fitness procedure optimizes locally the distance between the Target Set and the SSG pairs. Through a parametric score the user controls dynamic changes in the sound output.