Measurements are presented of the sound power radiated by panel excited by turbulent boundary layers with air velocities up to Mach number 0.64. The test panels were mounted in a test section of an acoustically quiet air duct that was enclosed in a concrete reverberation room. The mean‐square exciting pressure fluctuation of the wall and the mean‐square panel displacement in broad and narrow bands were measured. The radiated sound power and mean‐square displacement was found to vary proportional to (Mach No.)A× (panel thickness)−B, depending on the predominant modes of vibration. Some of these results are compared with flight‐test data.