Abstract

This paper studies the behaviour of circular membranes when stimulated by impact on different points. Taking into account properties of the excitation, patterns were searched between the oscillation of the membranes, hearing perception and changes in sound spectrum. For the development of this investigation, several instruments with circular membrane were used and their acoustic emission was recorded and analyzed. The results of this experiences showed that as closer to the perimeter the stimulation occurs, greater amount of vibration modes can be found and the oscillation pattern becomes less predictable. This causes in the sound spectrum an increase in number and levels in the superior partials.