How does increasing the Amplitude of a sound wave affect the sound produced?

Question

How does increasing the Amplitude of a sound wave affect the sound produced?

1. A. The loudness increases (Correct answer)
2. B. The pitch increases
3. C. The frequency decreases
4. D. The speed of the sound increases

Correct Answer

Option A — The loudness increases

Detailed Solution & Explanation

The correct answer is The loudness increases.

Key Points

• Amplitude is the maximum displacement of particles from their rest position, and it determines the energy the wave carries. Greater amplitude means greater energy, which the ear perceives as greater loudness.
• Each distractor names a property governed by something else:
  • Pitch depends on frequency, not amplitude.
  • Frequency is fixed by the source and does not change when amplitude does.
  • Speed depends on the medium — its density and elasticity — not on the wave's amplitude.

Additional Information

• The three characteristics of sound and their determinants are worth holding as a set: loudness ← amplitude, pitch ← frequency, quality or timbre ← waveform.
• Loudness is measured in decibels (dB) on a logarithmic scale, and intensity is proportional to the square of the amplitude — doubling amplitude quadruples intensity.
• The audible range for humans is roughly 20 Hz to 20,000 Hz; below is infrasound, above is ultrasound.
• Sound travels fastest in solids, slower in liquids and slowest in gases, and cannot travel through a vacuum at all — it needs a material medium.