In this paper, a sound reception system using a phase difference of whistle signals is proposed and analyzed through a spectral analysis. The proposed system receives whistle signals from four microphones which are installed toward four directions with 90 degree interval at the position. The proposed algorithm detects the phase of each received signal through the spectral analysis and estimates the direction of the whistle signal by obtaining the phase differences of the received signals from two adjacent microphones. Also, we theoretically analyze the phase difference between two adjacent received signals according to the arrival angle of the received signal and implement the proposed system using DSP chip. In addition, we verify the operation of the proposed algorithm using the implemented system in a laboratory environment. Experimental results show that the proposed scheme can well estimate the direction of the whistle signal.