To meet the stringent image placement error budgets for the insertion of 157-nm lithography in the sub-65 nm regime, photomask-related distortions must be minimized, corrected, or possibly eliminated. Sources of distortions include the pellicle system, which has been previously identified as a potential cause of image placement error. To characterize the many aspects of static pellicle-induced distortions, experiments have been conducted, and comprehensive finite element simulations have been performed for hard pellicle systems. The results of these benchmarking studies showed the capabilities of modeling and simulation to accurately predict static pellicle-induced distortions. In addition, the dynamic response of hard pellicles during exposure scanning was determined, taking into account both inertia effects and fluid / structure interaction. This paper focuses on the vibratory response of modified fused silica (hard) pellicles due to acoustic / dynamic pressure loadings during exposure scanning, studied both experimentally and numerically. A modal analysis was performed, the structural damping of the pellicle system was assessed, and a harmonic study was conducted to characterize the effects of acoustic excitation. The results obtained facilitate the timely establishment of viable hard pellicle designs and related standards for 157-nm lithography.