Sound pressure level measurement and spectral analysis of brief acoustic transients.

The sound pressure level (SPL) of an acoustic transient can be quantified in several ways. The SPL value obtained is dependent on measurement procedure, in addition to signal and transducer characteristics. The acoustic spectrum of a signal shows sound pressure as a function of frequency. The acoustic spectrum can be determined by the use of analog filtering or by Fourier transformation. A constant electrical signal can produce different acoustic spectra due to varying transfer functions across transducers. Signal center frequency, rise/fall time and plateau influence acoustic spectrum. Recording parameters, such as constant bandwidth versus logarithmic bandwidth filtering, or the time domain windowing function used prior to Fourier transformation, also influence the acoustic spectrum.