Broadband sound absorption plays a vital role in many engineering applications, and evaluating an absorber’s effectiveness often involves calculating the total energy absorbed across a wide frequency range. Given that ambient sound environments are typically characterized by pink noise spectra, integrating absorption coefficients over a logarithmic frequency scale serves as a practical performance indicator. This study examines this integral using a simplified piston model, deriving analytical expressions to gain insights into the underlying physics. Results indicate that reducing stiffness generally improves broadband absorption, while simultaneously decreasing mass and stiffness in a coordinated manner yields optimal performance. The exact values of these, together with the optimal damping, depend on the chosen frequency limits. Although the piston model is a simplified representation, a detailed comparison with more sophisticated sound absorbers is conducted to identify key differences. Based on these findings, practical recommendations are proposed for future absorber designs, emphasizing the importance of tuning stiffness, mass, and damping parameters. These insights contribute to advancing broadband sound absorber development, offering a clearer understanding of how simplified models can inform more effective, real-world acoustic solutions.
Zhang et al. (2025) studied this question.