A method of assessing noise involves evacuating air from a vacuum chamber to a pressure less than about 1 Torr and stimulating a device positioned in the chamber by shaking it or by operating a component of the device. Measuring vibrations in a low pressure environment decreases or eliminates propagation of sound waves, thereby enabling isolation and identification of vibrations caused by mechanical noise. These measurements may be useful for more precise acoustic characterization of audio devices containing multiple components.