Question

Sam is standing in an empty auditorium. He yells and hears his voice echo. What is happening to the sound to cause this echo?
A.
distribution of the sound waves through the auditorium
B.
absorption of the sound waves by his voice
C.
reflection of sound waves off the walls
D.
transmission of the sound waves within his ears

Answer 1

C. Reflection of sound waves off the walls.

When Sam yells, sound waves travel outward, hit the walls and other surfaces, and are reflected back to him. If the reflected sound arrives sufficiently later than the direct sound, he perceives it as an echo.