Resumen de On the acoustical characteristics of a balloon
When measuring the acoustical properties of large rooms, we know from experience that an inflated balloon can be an effective and consistent sound source in the far field. Aside from some data presented by Watters and Griesinger, there is very little documentation in the literature regarding the near-field sound pressure spectrum or the directional characteristics of this common acoustical source. The present paper describes some experimental measurements of balloons exploded both in a large room and also in a free sound field. In the free-field case, the sound pressures at one meter were measured by an array of microphones distributed over the balloon's surface. The data from the microphones were recorded on a multi-channel tape machine along with a synchronizing signal from an electrical detonator. The internal pressure and size of each inflated balloon was controlled prior to detonation. We found that the repeatability of the near field sound pressures (in 1/3 octave bands) was within two decibels above 100 hertz.
