In-air passive acoustic source localization is important to the design and implementation of tangible acoustic interfaces for computer human interaction. The methods used for in-air passive acoustic source localization are discussed in this paper. A time delay estimation method based on general cross-correlation was chosen for the application. In addition, a phase transform and smoothed coherence transform are combined to suppress the reverberation and background noise from the environment. MATLAB simulations and practical tests were carried out
under real reverberation conditions. Simulation and test results show that the method is effective and robust for single
in-air passive acoustic source localization.