Reflection

Acoustic reflection occurs when a sound wave encounters a surface and bounces back into the room rather than being absorbed or transmitted. The angle of reflection equals the angle of incidence for specular (mirror-like) reflections from large, flat, hard surfaces. Reflected sound energy contributes to reverberation, early reflections, and the perceived spaciousness of a room. In room acoustics, early reflections (arriving within 50 ms of the direct sound) can enhance speech intelligibility by reinforcing the direct signal, while late reflections contribute to reverberant tail and potential echoes. Hard, smooth surfaces like concrete, glass, and plaster have reflection coefficients above 0.95. Controlling reflections through absorption and diffusion is central to acoustic design for any room type.