It is often useful to quantitatively measure (or at least estimate) the amplitude of an acoustic event such as a bird song. The desired measurement could be, for instance, that a bird sang at 105 dB SPL (re 20 uPa) at 1 m.
However, I am unsure how to best estimate the sound level of an event, even if it is possible to record the event at a known distance with a calibrated microphone or a sound level meter. For the purpose of this question, let's assume that we record a sound event originating from a point source which has well defined boundaries in frequency and time and a high signal to noise ratio above background noise. We record the event exactly 1 m from the source. We are not concerned with directionality, we assume all measurements are “on axis”. How should we quantify the sound pressure level in dB SPL @1m (or some other measure of sound pressure) of the event?
- Should we measure some average (such as rms) over the duration of an event or the peak value?
- Should we take a measurement at specific frequencies or across the frequency spectrum?
- Should the background noise measurement be subtracted in some way from the signal measurement, as in the methods of