A broad‐band acoustic instrument consisting of a white‐noise generator and a damped piezoelectric receiver has been used to analyze the frequency spectra of 0–3 MHz acoustic surface waves on complex structures. By varying the path length, the frequency dependence of attenuation can be obtained. This attenuation data are used in the design of acoustic emission monitoring systems, where the frequency‐dependent characteristics of the acoustic paths between possible acoustic emission sources and the detection transducer are needed. In addition, the data can be directly used in characterizing structures such as honeycomb sandwich panels where defects produce changes in the surface wave attenuation. The system used to make these measurements are described and results for a variety of structures are presented.