Sound propagation over grass

This study investigates sound propagation over the grass panicum maximum. The attenuation spectrum displays absorption dips at low and mid-frequencies (32 - 63 Hz and 500 - 2000 Hz) with emission peak at 250 Hz and a steady increase in attenuation from 2000 Hz. The band pressure levels exhibit a wide spread for propagation 0.4 - 2.0 m above grass at frequencies of 32 and 63 Hz, and a narrow spread for propagation 1.2 - 2.0 m above grass in all the 1/3-octave bands above 63Hz, where there were observed characteristic dips at 1.8m. The results show possible use of panicum maximum in environmental noise control.