Assessment of Noise with Low Frequency Line Spectra — Practical Cases

Abstract

Many small power plants have been built in Denmark in recent years. These plants are often situated near dwellings giving rise to complaints about annoyance of low frequency noise and vibration indoors. Normally the annoying low frequency noise is in the frequency range 10–200 Hz. Since it is created by combustion engines the noise has a line spectrum. In Denmark the A-weighted total level in the frequency range 10–160 Hz LpA, LF is used for assessment and legislation about low frequency noise exposure in dwellings. From our experience solving practical low frequency noise and vibration problems LpA,LF seems to overestimate the annoyance of very low frequency noise whereas noise with the major spectral content near 160 Hz seems to be underestimated. This problem is discussed based on our experience.