## 1 Introduction
When the elevation angle is near the extreme angles of either zero or \(90^{\circ}\), the error will be more obvious, which clearly affects the precision and stability of the sound source localization. The problem is that the precision and stability of the sound source are adversely impacted by the sound source at an extreme angle. Therefore, in this paper, based on the analysis of a sound source geometry localization algorithm, a theoretical model for a five-element microphone array is established, using the time-delay values to determine the quadrant of the sound source position to solve the problem in which a single-plane array is prone to producing azimuth blurring. By deducing the formula of the sound source position calculation in a single-plane array, the sine and cosine values of the two elevation angles are used as weighting coefficients and are introduced into the sound source spherical coordinate formula. A sound source localization fusion algorithm of a three-plane five-element microphone array is proposed for studying sound source localization. According to the error analysis formula, the relationship between the ranging and direction-finding precision and the array element spacing, horizontal angle, elevation angle, and time-delay estimation error are obtained, and the performance of the sound source localization is analyzed. By experimentally adjusting the sound source position and array element spacing, the fusion algorithm is used to obtain the sound source coordinates. Based on forward data, the measured data are compared and analyzed. In this paper, the proposed sound source localization fusion algorithm was used to locate the actual sound source, and compare it with theoretical data, radar chart data, and important literature. The experimental results showed that by appropriately increasing the array element spacing of the three-plane five-element microphone array, the sound source position could be measured more accurately and stably than the single-plane array. At the same time, the thunder source point data measured by the fusion algorithm could be used to provide data feedback for thunderstorm cloud forecast warnings, and could be used to track the moving path of the thunderstorm cloud in real time. In particular, the fusion algorithm could effectively reduce the negative impact of the sound source at an extreme angle on localization performance, and these conclusions were not achievable with existing sound source localization algorithms. In Section 2, we analyzed the finite element microphone array theory, established a three-plane five-element microphone array model, and gave the quadrant judgment criteria for the location of the sound source. In Section 3, aiming at the problem that the sound source at an extreme angle had a negative impact on the performance of sound source localization, we proposed a sound source localization fusion algorithm and gave its calculation steps. In Section 4, based on the theory of indirect measurement error, we analyzed the error generated by the fusion algorithm for sound source localization, and theoretically supported the effectiveness of the algorithm. In Section 5, indoor, outdoor, and contrast experiments were performed using the fusion algorithm, and performance comparisons were compared with the latest relevant literature. In the last part, the application prospect of the sound source localization fusion algorithm was prospected, and the consideration of the next research work was given.