Aiming at the sound absorption problem of anechoic coating in water seepage state, firstly, the sound absorption coefficient of anechoic coating in infinite water area with steel plate as backing is calculated based on transfer function method and finite element method, anAd the solution results are compared with the analytical result of uniform layered medium to verify the correctness of the solution method. Secondly, the calculation model of cavity containing anechoic coating with different seepage proportion is established to analyze the influence of water seepage on the sound absorption performance of anechoic coating. The calculation results show that within the calculated frequency band, water seepage proportion has different influence characteristics on different frequency bands of anechoic coating, and with the aggravation of water seepage, the peak point of sound absorption moves to medium and low frequency, and the singular value point of sound absorption coefficient moves to high frequency; and the singularity of the valley value of the sound absorption coefficient is mainly due to the change of the cavity resonance mode. The results of this paper can provide some reference for the acoustic performance evaluation of abnormal state of anechoic coating.

To address the bottleneck of insufficient broadband sound insulation performance of traditional sound insulation materials at the subwavelength scale, this paper designs a composite subwavelength sound insulation unit (size: 20 mm × 20 mm × 5 mm) composed of Ti₃C₂T_x MXene, and PZT-5H piezoelectric ceramics, and porous aluminum alloy. Based on the electromagnetic-structural-acoustic multi-physics field coupling theory, the regulation laws of external electric field intensity and effect of MXene layer number on sound insulation performance are systematically investigated via numerical simulation, and the sound insulation enhancement mechanism dominated by dielectric tunability is clarified. The results show that the dielectric constant of MXene increases monotonically with the external electric field intensity, and the optimal regulation sensitivity is achieved when the layer number N = 3; when the electric field intensity increases from 0 V to 500 V, the equivalent density of the system increases from 1.25 g/cm³ to 1.87 g/cm³, the acoustic impedance increases from 3.42 × 10⁶ Pa·s/m³ to 5.13 × 10⁶ Pa·s/m³, the average transmission loss TL in the 200–600 Hz frequency band is increased by 2 dB compared with the state without electric field, and the sound pressure on the transmission side is reduced by 3.56% at 400 Hz; the vibration displacement of PZT decreases from 0.0055 mm to nearly 0 mm with the increase in electric field, and the electric field energy density increases from 0 J/m³ to 7.47056 × 10³ J/m³, verifying the core mechanism of converting electromagnetic energy into structural damping through dielectric loss. This study supplements parameter sensitivity analysis and literature benchmark comparison to compensate for the lack of experimental data, confirming the stability and rationality of the simulation results. The established cross-field coupling framework of “dielectric regulation–density optimization–impedance matching–sound insulation enhancement” fills the theoretical gap of the coupling mechanism of MXene in the field of subwavelength sound insulation, and provides new theoretical and technical pathways for the design of broadband active sound insulation materials in the 200–1000 Hz frequency range.

Active sonar serves as a critical technological means for detecting, locating, and countering underwater targets. Addressing the inherent issue of poor concealment in active detection, achieving undetected underwater detection capabilities presents a significant research challenge. Drawing inspiration from biomimicry, this study adapts biological intelligent acoustic signals, detection logic, and processing capabilities to conventional sonar systems. By integrating intelligent algorithms, it aims to resolve the challenge of covert detection of underwater targets in complex marine environments. Results demonstrate that the WaveGAN-based intelligent fitting algorithm effectively achieves biomimetic signal feature adaptation. A combined optimization method adjusting pulse intervals and pulse source levels significantly enhances system efficiency, reducing sampling points by approximately 45% and processing time by about 42%, while markedly improving overall system energy efficiency. This research provides valuable insights for biomimetic underwater detection applications.