Which of the following factors determines the loudness of a sound?
a. frequency of the sound wave
b. amplitude of the sound wave
c. the temperature of the medium
d. the density of the medium
The correct answer is b. amplitude of the sound wave.
To understand why the amplitude of the sound wave determines the loudness of a sound, we need to understand a few concepts.
Sound waves are vibrations that travel through a medium, such as air or water. When an object or a source produces a sound, it creates vibrations that cause particles in the medium to vibrate, creating a wave of compression and rarefaction. These waves eventually reach our ears and are perceived as sound.
The amplitude of a sound wave refers to the maximum displacement of particles from their resting position as the wave passes through. In simpler terms, it is the distance between the highest and lowest points of the wave.
When the amplitude of a sound wave is greater, the compressions and rarefactions are more intense. This results in a larger variation in pressure, which our ears perceive as a louder sound. In contrast, when the amplitude is smaller, the variation in pressure is smaller, and the sound is perceived as softer.
So, to determine the loudness of a sound, we look at the amplitude of the sound wave. The greater the amplitude, the louder the sound, and vice versa.
Factors like the frequency of the sound wave, the temperature of the medium, and the density of the medium can affect other characteristics of a sound, such as its pitch or speed, but they do not directly determine its loudness.