The field experiments of the noise propagating over the ground were carried out, varying the combination of height of an artificial noise source and a receiving point. We pay attention to the excess attenuation obtained from the noise propagating over the ground. The results obtained are as follows: (1) The excess attenuation of the low frequency obtained from the noise propagating over the soft ground is larger than we expected and also affected by the wind; (2) the excess attenuation obtained is, as a whole, larger in summer than in winter. From the data obtained, the empirical equation predicting the excess attenuation is introduced. [T. F. Embleton, J. E. Piercy, and N. Olson, J. Acoust. Soc. Am.59, 267–277 (1976)] Furthermore, referring to the data measured by other researchers [P. H. Parkin and W. E. Scholes, J. Sound Vib.2, 353–374 (1965)], it is shown that the equation is applicable to predict the excess attenuation over the ground.