Pitch and loudness

Sound is a fascinating phenomenon that happens around us every day. Whether it is the chirping of birds, the sound of cars or the sound of someone speaking, we interact with sound in various ways. Two important characteristics of sound that we often discuss are pitch and loudness. These aspects help us understand what differentiates different sounds from each other. In this article, we will learn about pitch and loudness in detail, find out what they mean, how they work and their significance in the world of sound.

What is sound?

Before we dive into pitch and loudness, let's briefly understand what sound is. Sound is a type of energy created by vibration. When an object vibrates, it creates a sound wave that travels through a medium, usually air, causing a change in pressure. These waves travel to our ears, where our brain interprets them as different sounds.

Pitch: the high and low pitch of a sound

Pitch refers to how high or low a sound is. This is determined by the frequency of the sound wave. Frequency is the number of vibrations that occur per second and is measured in hertz (Hz). Higher frequency means more vibrations per second, and thus, higher pitch. Lower frequency means fewer vibrations and a lower pitch.

Frequency and pitch

Frequency (f) = Number of cycles / Time (seconds)

For example, the flute sounds high because its frequency is high. The cello sounds low because its frequency is low. When a singer plays a high note, he or she produces a higher frequency sound than when he or she sings a low note.

Imagine a guitar string. When you play it, it vibrates and produces sound. If the string is short and tight, it will vibrate fast and produce a high pitched sound. If it is long and loose, it will vibrate slow and produce a low pitched sound.

This diagram shows how a taut string vibrates and produces a high tone.

Imagine that if you adjust the tension or length of the strings, this will change the frequency, and therefore the pitch of the sound produced. In real life, musical instruments use this principle to produce different notes. For example, a guitar player changes the pitch of the strings by applying pressure to different frets, effectively changing the tension and length of the strings.

Pitch in everyday life

Tone plays an important role in music. Musicians tune their instruments to produce exactly the tone they want. Tone helps us recognize familiar tunes and melodies. In addition to music, tone is also very important in spoken language. Changes in tone can change the meaning of words or sentences, especially in tonal languages such as Chinese.

Loudness: the volume of the sound

Loudness, on the other hand, means how powerful or intense a sound seems. It is measured in decibels (dB) and depends on the amplitude of the sound wave. The larger the amplitude, the louder the sound will sound. Compare a large wave in the ocean to a small one. The larger the wave, the more "force" it has. It's the same with sound waves.

Amplitude and loudness

The amplitude of a sound wave is the maximum extent of vibration or oscillation, measured from an equilibrium position. Higher amplitude means the particles of the medium move more, resulting in a louder sound.

Think of a drum. When you hit it softly, you create a small amplitude, which produces a softer sound. When you hit it hard, you create a larger amplitude, and the sound gets louder.

This diagram shows that the amplitude of the vibration can be small (black circle) or large (red circle), which affects the intensity.

Different activities produce different amplitudes of sound. For example, whispering produces smaller amplitudes of sound waves, while shouting produces larger amplitudes of sound waves.

Noise in everyday life

Loudness affects our everyday interactions to a great extent. It affects how we communicate and understand each other. In conversation, adjusting loudness helps to convey emotions and intentions. Loudness also affects our environment; for example, loud noise in a busy city is often perceived as noise pollution.

Imagine you are sitting in a quiet park: the sounds around you are probably soft, like the chirping of birds or the rustling of leaves. Now imagine yourself at a rock concert where large speakers play loud music with high amplitude sound waves. You will immediately notice the huge difference in sound levels.

Relation between pitch and loudness

Pitch and loudness, although distinct, interact in interesting ways. You can see that sometimes increasing the pitch also seems to increase the loudness, even if there is no change in amplitude. Still, these should be considered as independent characteristics. For example, a high-pitched whistle can be very soft or very loud, and a deep drum sound can also vary in loudness without changing the pitch.

Explore both concepts with examples

Example 1: A violin and its strings

The violin is a great example to understand pitch and loudness. By tightening or loosening the strings, pitch changes due to a change in frequency. By changing how hard the bow is pulled across the strings, loudness changes due to a change in amplitude.

This picture shows a violin string; changing the tension affects the tone, and applying force affects the loudness.

Example 2: Speaking or singing

Pay attention to this when you speak or sing. When you sing louder, your vocal cords vibrate faster, increasing the intensity of the sound. To make your voice louder, you force more air out of your lungs, which increases the amplitude of the sound wave.

If you sing softly or loudly, it conveys a sense of calm. In contrast, singing loudly or loudly can produce a dramatic and powerful sound. Similarly, a calm and soft voice conveys a message of peace, while a loud and soft voice conveys a sense of urgency.

Scientific instruments and measurements

In the technical field we use special instruments to measure pitch and loudness. An instrument called an oscilloscope can display the wave pattern of sound. The frequency (pitch) and amplitude (loudness) of the wave can be analyzed. Loudness is usually measured with a decibel meter, which measures the intensity of sound in the environment.

Pitch is often adjusted using a tuner to precisely match desired sound levels in musical instruments or music production.

Summary

Understanding pitch and loudness helps us understand the fundamental and fascinating properties of sound. Pitch gives sound its musical tone, allowing us to experience melodies and communicate the nuances of language. Loudness refers to the strength or intensity of sound, which affects how we perceive and interact with our surroundings.

Sound is an integral part of life, and appreciating its dynamics enhances our ability to engage with the world in a rich, auditory dimension. Armed with this knowledge, we can better understand the various sounds in our daily environment, from quiet whispers to energetic symphonies.

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