If large echoes are to be avoided, focusing of the sound wave must be avoided. Smooth, curved reflecting surfaces such as domes and curved walls act as focusing elements, creating large echoes and leading to bad texture. Improper blend results if sound from one part of the…

…familiar in the phenomenon of echoes is reflection. This plays a critical role in room and auditorium acoustics, in large part determining the adequacy of a concert hall for musical performance or other functions. In the case of light waves passing from air through a glass plate, close inspection shows…

The reflected echoes are received by an electronic apparatus that determines the intensity level of the echoes and the position of the tissue giving rise to the echoes. The images thus formed can be displayed in static form, or, through the use of rapid multiple sound scans,…