Investigation of acoustic signals is crucial for detecting leaks in subsea gas pipelines and preventing economic losses. This study presents a three-dimensional (3D) computational fluid dynamics model for analyzing the acoustic characteristics of subsea gas pipeline leaks. The model considers different operating pressures, hole sizes, and shapes. The Ffowcs Williams and Hawkings model was employed to capture the acoustic characteristics of sonic waves generated by pipeline leaks. The impact of pipeline pressure, hole size, and shape on acoustic characteristics was examined focusing on low-frequency acoustic pressure, high-frequency acoustic pressure, and average acoustic pressure. The results indicated that the average sound pressure level increases with the higher pipeline operating pressure. For the circular leak holes, the average sound pressure level rises with increasing hole size, and leaks from circular holes exhibit the highest average sound pressure level. Additionally, the sound pressure level decreases as the frequency increases. The outcomes can help to understand the knowledge of underwater gas pipeline leak. Besides, it is the important inputs for developing the acoustic localization model of subsea gas pipeline leak.