To investigate the internal sound field of an enclosed cabin equipped with intake and exhaust ducts, numerical acoustic simulations were conducted using the acoustic module of the finite element software LMS Virtual Lab. The study focused on acoustic performance indicators such as the insertion loss of the intake and exhaust mufflers and examined the influence of the intake muffler on the cabin's sound field. The simulation results indicate that the pressure losses of the intake and exhaust mufflers are 19 kPa and 72 kPa, respectively, both meeting the design requirements. Within the frequency range of 20 Hz to 20 kHz, the insertion loss of both mufflers generally complies with the standard, though certain frequency bands still require further optimization. Specifically, the overall noise reduction effect of the intake muffler is slightly lower than that of the exhaust muffler, while the exhaust muffler’s noise attenuation performance in the high-frequency band needs improvement. From the cabin perspective, installing mufflers in the intake duct effectively reduces mid- and high-frequency noise inside the cabin. Additionally, accumulated water in the cabin smooths the sound spectrum and reduces noise, with this effect gradually stabilizing as water depth increases. This study provides valuable insights for optimizing the acoustic design of ship cabins.