ENVIRONMENTAL BASELINE MONITORING IN THE AREA OF GENERAL CRUDE OIL-DEPARTMENT OF ENERGY, PLEASANT BAYOU NUMBER 1--Annual Report Volume IV--APPENDIX III:

as the inverse square of the distance of the rece.iver from the source. [...] The amount of attenuation depends on the type of vegetation and on the path of the Sound wave. [...] , noise) depends upon three things: The strength and character of the intruding noise , The level of background (ambient) noise exist- ing prior to introduction of the intruding noise, and The type of working or living life styles of humans occupying the area under study. [...] The strengh_ and character of intruding noise are de- scribed by (1) the frequency distribution of the noise, (2) the noise level, and (3) the time pattern of noise. [...] The second factor, level of ambient noise, is important because humans tend to judge added and intruding noise on the basis Of the noise that was present prior to the time that the new noise Was introduced.