Define attenuation and describe the 3 main contributors (absorption, reflection, refraction) Attenuation: decrease in intensity, power, and amplitude as sound travels. Determined by path length and frequency of sound. The greater the attenuation, the weaker the beam becomes. Frequency and attenuation are directly related energy may be redirected back to the sound source. Reflection: as sound strikes a boundary, a portion of the wave"s. Likely to occur when the dimension of the boundary is. Specular: when boundary is smooth and sound is reflected large, few wavelengths of sound in only one direction in an organized manner. Ex: light from a mirror, reflections on the calm, smooth surface of a pond, and reflections from polished metal surfaces. Angle of incidence always equals the angle of reflection. Diffuse: wave reflects off an irregular surface, it radiates in more than one direction; lower strength but can still produce reflections that will return to the transducer.