| 摘要 |
This invention concerns environmental noise monitoring, and more particularly a system and method for environmental noise monitoring. The environmental noise monitoring system comprises three or more sound level transducers arranged apart from each other in an environment containing one or more noise sources. Each transducer is arranged to pick up sounds arriving from all directions and to transduce the sounds into electrical signals. The sound level and direction measuring equipment includes signal samplers connected to respective transducers to receive electrical signals representing environmental sounds and to sample the electrical signals. A computer processor is further provided to perform cross correlation calculations to generate a cross correlation function for each pair of sampled signals. The processor identifies local maxima in the cross correlation functions, estimates the angle of arrival of the sound associated with a local maximum and the sound pressure level associated with the maximum, and uses the estimates of the angles from all cross correlation functions to identify a source of noise in a particular direction and the level of noise from that source, and then identifies additional sources of noise in different directions and the levels of noise from those sources. Noise levels from sources in particular directions may be accumulated, displayed and saved for reference.
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