Question

In Acoustics, 'Noise' is generally characterized by:

• A. Irregular and non-periodic vibrations.
• B. A constant pitch and frequency
• C. Vibrations that follow a harmonic series
• D. Regular and periodic vibrations

Hint:

Music has patterns; Noise has none.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
In acoustics, a distinction is made between "musical sound" and "noise." Musical sound is produced by regular, periodic vibrations that create a recognizable pitch. Noise, however, lacks this structure.
Step 2: Key Formula or Approach:
Analyze the waveform: Periodic = Musical; Non-periodic/Random = Noise.
Step 3: Detailed Explanation:
Noise is the result of sound waves that have no definite frequency or pattern. Because the vibrations are irregular and do not repeat at set intervals (non-periodic), the human ear cannot assign a specific pitch to the sound. This is why white noise or a crashing sound feels "discordant" compared to a piano note.
Step 4: Final Answer:
Noise is characterized by irregular and non-periodic vibrations.