The Loudness of a Sound: How It Is Related to Its Amplitude

Sound is a form of energy that travels in waves through a medium, such as air, water, or solid objects. We can hear sounds when these waves reach our ears and cause our eardrums to vibrate. The sounds we encounter in our daily lives vary in many ways, such as their pitch, quality, and loudness. In this article, we will focus on the loudness of sound and how it is related to its amplitude.

What is Loudness?

Loudness is a subjective measure of how loud or soft a sound is perceived by a listener. It depends on several factors, such as the intensity of the sound wave, the distance from the sound source, the sensitivity of the listener’s ear, and the background noise level. Loudness is usually measured in decibels (dB), which are units that express the ratio of two sound intensities.

According to Vedantu, loudness is directly proportional to the square of the amplitude of the sound wave. Amplitude is the maximum displacement of the particles in the medium from their equilibrium position when a sound wave passes through them. It reflects how much energy the sound wave carries. The larger the amplitude, the more energy the sound wave has, and the louder it sounds.

Examples of Loud Sounds and Their Amplitudes

To illustrate how loudness and amplitude are related, let us look at some examples of common sounds and their approximate amplitudes and loudness levels.

  • Normal breathing has an amplitude of about 0.001 micrometers (µm) and a loudness of about 10 dB.
  • A soft whisper at 5 meters has an amplitude of about 0.01 µm and a loudness of about 30 dB.
  • A normal conversation has an amplitude of about 0.1 µm and a loudness of about 60 dB.
  • A busy traffic has an amplitude of about 1 µm and a loudness of about 70 dB.
  • An average factory has an amplitude of about 10 µm and a loudness of about 80 dB.

As we can see from these examples, as the amplitude increases by a factor of 10, the loudness increases by about 20 dB. This means that every time we double the amplitude, we increase the loudness by about 6 dB.

How Does Loudness Affect Our Hearing?

Loud sounds can have both positive and negative effects on our hearing. On one hand, loud sounds can make us more alert, excited, or entertained. For example, listening to music at a high volume can enhance our mood and enjoyment. On the other hand, loud sounds can also damage our hearing, cause stress, or disturb others. For example, exposure to noise above 85 dB for prolonged periods can cause permanent hearing loss or tinnitus (ringing in the ears).

According to Toppr, noise is defined as sounds above 80 dB that are unpleasant or harmful to our ears. Some sources of noise pollution include industrial machines, vehicles, aircrafts, fireworks, concerts, and loudspeakers. To protect our hearing from noise-induced damage, we should avoid or limit our exposure to loud sounds, wear earplugs or headphones when necessary, and seek medical attention if we experience any signs of hearing problems.


In conclusion, the loudness of a sound is most closely related to its amplitude, which is the measure of how much energy the sound wave carries. The larger the amplitude, the louder the sound. Loud sounds can have both positive and negative effects on our hearing, depending on their intensity and duration. We should be aware of the sources and levels of sound around us and take appropriate measures to protect our hearing health.

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