As a first approximation, sound waves can be described using rays to express position, propagation direction,...
As a first approximation, sound waves can be described using rays to express position, propagation direction, and propagation path. An equation describing echo can be defined as; y(n) = x(n) + Ža,x(n-de) k=1 where : x(n) represents the straight path signal a, is an attenuation factor between 0 and 1 for reflected signals d. is a time delay for reflected signals In this equation y(n) is the sound sink and the straight path ray from the sound source is represented by x(n). The summation represents any reflected rays that make it to the sink. The summation takes into account the energy loss due to reflection ak and the increase in time, or delay dk, taken to reach the sink. The scenario for three rays is shown in the figure 11. Here the source is the speaker and the sink is the microphone.