During summer season and winter season of 1971 and 1972, the acoustic properties, defined as the acoustic climate, of 8 semi-natural plant communities in the Netherlands were investigated. It appeared that each plant community has its own acoustic climate as a consequence of the specific species composition and the specific acoustic properties of the soil. Seasonal changes influenced the acoustic climate to some extent, since during summer there is a better attenuation of low frequencies and in winter of mid frequencies. Comparing all plant communities the total variation in attenuation differed from 29.6 dB/100 m at 1250 Hz (cps) in winter to 74.6 dB/100 m at 10,000 Hz in summer, as is shown in Table 3. In general best attenuation occurred at low and high frequencies in both seasons, which has to be attributed to soil and foliage characteristics.