Destructive interference results in:

Destructive interference results in:

• A. A louder sound
• B. A higher pitch
• C. A quieter sound
• D. A lower pitch

Answer: (C)

Destructive interference happens when two sound waves meet with opposite phases, so their highs line up with the other’s lows and they cancel each other out. This lowers the overall amplitude of the combined wave, making the sound quieter. Pitch, or how high or low a note sounds, depends on the frequency of the waves, not how they add together, so interference doesn’t make a sound higher or lower in pitch. If the waves cancel perfectly, you could even reach silence. That’s why a quieter sound is the best answer. (Noise-canceling technology uses this idea to reduce unwanted sound by creating destructive interference.)

Destructive interference happens when two sound waves meet with opposite phases, so their highs line up with the other’s lows and they cancel each other out. This lowers the overall amplitude of the combined wave, making the sound quieter. Pitch, or how high or low a note sounds, depends on the frequency of the waves, not how they add together, so interference doesn’t make a sound higher or lower in pitch. If the waves cancel perfectly, you could even reach silence. That’s why a quieter sound is the best answer. (Noise-canceling technology uses this idea to reduce unwanted sound by creating destructive interference.)