ABSTRACT
Sound propagates from a source as a series of rapidly fluctuating pressure waves which expand spherically as they move away from the source (Figure 3.1(a)). These pressure waves create the sensation of noise when they reach the listener’s ear. Although sound travels as waves it is often convenient to model sound propagation as straight lines or rays, which reach the listener or receiver either directly or indirectly after being reflected or diffracted by intervening surfaces (Figure 3.1(b)). The ray-tracing method is used below to describe commonly occurring screening scenarios.
