CONTENTS Foreword Summary Introduction Facilities, Equipment, and Procedure Experimental Results Tree-Covered Land-Forms --- Bare Land-Forms --- Actual "Live-Sound" Tests --- Octave-Band Analysis --- Special Application Study--Site 4--I-80 Rest Area Statistical Analysis Site 1: Hastings Tape-Recorded Sound --- Sites 2 and 3: Milford Highway Cuts and Fills Observations and Conclusions Tree-Covered Land-Forms --- Bare Land-Forms --- Tree-Cover Effect --- Land-Form Height Effect --- Wind Effect --- Trees vs. Land-Form Considerations --- Limitations and Requirements of Outdoor Noise Control---Establishing Trees and Shrubs on Land-Forms Recommendations Appendix A. Glossary of Technical Terms Appendix B. Selected List of Trees and Shrubs Appendix C. References