Do interference effects occur for sound waves?

Yes, the interference effect occurs for sound waves despite the fact that sound waves are longitudinal waves. When two sound waves of the same frequency and same amplitude in the same direction superpose then the interference of sound waves occurs.

For example, two loudspeakers emit two harmonic sound waves of fixed frequency produced by an audio generator. When these waves combine at a point in phase, the intensity of the resultant wave increases, and a loud sound is heard. This is known as constructive interference. While at some other point, these waves arrive in such a way that they are out of phase, so they cancel each other’s effect. Hence a faint or no sound is heard. This is known as destructive interference.