Equivalent Continuous A-weighted Sound Pressure Research Articles

Moments of probability distribution of equivalent continuous A-weighted sound pressure level(LAeqT).

When a noise arises from several individual noise events, then its equivalent continuous A-weighted sound pressure level (LAeqT) depends on the number of noise events (N), the A-weighted sound exposure levels (LAE) and the equivalent continuous A-weighted sound pressure level of the background noise (LAeqT). At least some of those quantities are random variables. Thus, the values of LAeca, measured within a constant time interval, are random as well. The results presented here make it possible to predict the mean and variance of LAeqT in terms of some characteristics of N, LAE, and LAeqT.

Traffic noise attenuation in an urban area in terms of A-weighted sound exposure level

This paper presents a method for calculating the A-weighted sound exposure level of noise generated during passage of a single vehicle. The excess attenuation of an urban area is taken into account. The Ground Area Index is used for urban area description. The results can be used for the approximation of the equivalent continuous A-weighted sound pressure level of traffic noise.

The ground effect in terms of A-weighted sound exposure level.

This paper presents contour charts for the A-weighted sound exposure level of noise generated during passage of a single vehicle. The ground effect has been taken into account for two types of surfaces. The results can be used for prediction of the equiv alentcontinuous A-weighted sound pressure level of traffic noise.

Sound levels from personal cassette players.

Techniques have been devised whereby the levels at which users of personal cassette players listen to tape-recorded sounds through lightweight headphones may be measured and expressed in terms of free-field equivalent continuous A-weighted sound pressure levels. Data have been obtained on over 60 users of such devices who variously listened, in laboratory and field conditions, to music and speech against quiet and noisy backgrounds. The results have been interpreted in terms of noise exposure. Comparison with damage risk criteria indicates that 5% of the sample are listening in such a manner that habitual use would constitute a damage risk to hearing.

Occupational noise exposure on construction sites

An exploratory study of the noise exposure of operators of plant and equipment on construction sites is described. Noise at the ears of operators has been measured in terms of maximum sound pressure levels and short-term values of the equivalent continuous A-weighted sound pressure level. It is shown that some operators are exposed to levels of noise at which it is currently recommended that hearing protectors should be worn. It is suggested that it may be possible to determine where hearing protectors should be worn either by reference to the type of plant or, for some equipment, by reference to the equipment's sound power level.