Noise Control, 2nd Edition

4

Sound Propagation Outdoors

LEARNING OBJECTIVES

In this chapter, the reader is introduced to the analysis of outdoor sound propagation, including:

• various phenomena affecting the sound pressure level arriving at the receiver, such as:

  • o spherical divergence;

  • o atmospheric absorption;

  • o ground reflection;

  • o atmospheric wind and temperature gradients and turbulence;

  • o source height;

  • o absorption by foliage;

  • o shielding by barriers, houses and process equipment/industrial buildings;

• commonly used methods of prediction, including the CONCAWE and ISO 9613-2 (1996) propagation models; and

• uncertainty.

4.1 Introduction

Sound propagation outdoors is a complex process, with the sound pressure level produced at a receiver by a source, at a ...