A Review of Acoustic Measurement Techniques

Abstract

One traditional method for measuring the AIRF of a music performance hall is to generate a brief, omnidirectional impulse of finite amplitude. These types of signal sources are typically produced by a starter’s pistol or through popping a balloon [10]. The impulse response of the hall is recorded on either a digital audio tape (DAT) machine or a computer (with appropriate software) for subsequent processing and analysis. Impulsive sources such as a starter’s pistol or balloon might provide a usable recorded signal-to-noise ratio (SNR) but there are problems of stability, repeatability, and bandwidth of the frequency response. Consequently, there is the absence of a normalized or consistent spectrum for the test signal, which makes it difficult to determine both the absolute spectral response of the hall being measured and the absolute sound pressure level (SPL) of the source.