What term is used for any disturbance that causes undesired change or degradation of a wave?

• A. Interference
• B. Noise
• C. Echo
• D. Reverberation

Answer: (A)

Describing any disturbance that causes undesired change or degradation of a wave points to noise. Noise is the broad term for unwanted energy that masks or distorts the original signal, reducing the clarity or integrity of what’s carried by the wave. It can be random, broadband, and present even when no other structured signal is present, which is what makes it a general nuisance in communication and sensing systems.

Interference, while related, refers to the interaction of two or more waves that meet and superpose. It can produce constructive or destructive effects depending on their phases, and isn’t inherently framed as an unwanted disturbance in every context. Echo is specifically a delayed reflection of a signal that returns and can disrupt timing or cause repetition. Reverberation is the persistence of sound due to many overlapping reflections, smearing the signal in time. Noise is the overarching term for the kind of undesired disturbance that degrades a wave in a general sense.