The majority of people in this world must have heard the sound of something. But have you ever
thought about where the sound we hear actually comes from? Why can sound appear?
When it’s silent, then someone suddenly opens the door, what will you hear? Or when
it’s silent then someone drops an object, surely we will hear a sound or sound right?
According to science, sound is produced in the form of pressure waves. When a certain object
vibrates, it causes the air molecules around it to vibrate, starting a chain reaction of vibrating sound
waves throughout the medium. While the definition of sound itself is a vibration in the air.
It should be understood that all things that can vibrate can certainly make a sound.
For example, when you talk, of course it will make a sound, right? Why?
Because there are vocal cords that vibrate in the throat.
Meanwhile, according to the law, sound will indeed sound louder if we are near the source of the sound.
Vice versa, the sound will be weaker if we are far from the source of the sound.
Therefore, if you talk to people at a considerable distance, of course you will hear their voices
that are vague and unclear.
Because various kinds of things related to sound exist in our lives, we must also understand the nature of
the sound itself. So, in this article, we will discuss the nature of sound, understanding, and
various other things related to the sound itself.
What Is Sound?
The definition of sound itself is a vibration in the air. Sound can be obtained from various
objects. Not only that, almost all living things in the world can produce a sound.
Where sound is wave energy that comes from a sound source, namely a vibrating object.
Because sound comes from a vibrating object, it causes the following phenomenon, that is, the
stronger the object vibrates, the stronger the sound will be produced.
Vice versa, if an object vibrates weakly, the sound produced will also be smaller. Each sound
has its own frequency depending on the sound energy source it has.
Sound Energy
Sound energy is a vibration that can produce sound. Where sound energy is also associated with
various kinds of abilities that occur due to the influence of sound. Thus, the source of sound
energy does not solely come from musical instruments. If there are two objects that rub against
each other, then these objects will also produce sound that we can hear.
Maybe a musical instrument is a source of sound energy that is familiar to our ears. However,
there are various sources of sound energy. Then, objects that can produce sound are called
sound sources. Humans themselves have a natural sound source. Like our vocal cords
which can produce sound when we are talking, singing, and so on. It is important to learn more
about sound and the various interesting facts contained in it.
Examples of Sources of Sound Energy
The simplest example of a sound is when a motorcycle is running from two different directions.
Then the motorbikes collide, so there will be a sound or sound that we can hear when there is a
collision between the two motorbikes.
Sources of sound energy can be found in musical instruments. Why can a musical instrument be a
source of sound? Because every musical instrument must have a resonator.
Meanwhile, a resonator is an air chamber that is useful for being able to amplify sound, for
example on a violin or guitar. When you pluck the strings on a guitar or violin, there will be
vibrations on those strings. From the existence of these vibrations, a sound will appear.
This phenomenon is often referred to as resonance.
Sound Wave
Sound waves are mechanical waves that can propagate through a medium and are also known as longitudinal
waves. Sound is a form of energy that exists in this world. In everyday life, of
course, we will always hear a sound that comes from various sounds. Starting from the sound of
music, the sound of motorbike horns, the sound of trains, the sound of people talking, the sound of
television, and many other sounds. We can hear all these sounds because of the source of the
sound or the sound itself.
Types of Sound Energy
The following are several types of sound energy that need to be understood:
1. Infrasound
Infrasound is a sound that tends to be weak. Where the number of sound vibrations in
infrasonic energy is less than 20 vibrations per second. Of course we cannot hear this type of
sound. However, animals such as crickets, dogs, geese, and also elephants can hear this type of
sound.
2. Audiosonics
Audiosonics are sounds that we can hear because the number of vibrations ranges from 20 to 20,000
vibrations per second. Not only humans, animals can also hear this sound.
3. Ultrasonic
Ultrasonic is a very strong sound and its level is above audiosonic. The number of sound
vibrations from ultrasonic reaches more than 20,000 vibrations per second. We cannot hear this
type of sound. Only bats and dolphins can hear this type of sound.
Sound Properties
Sound energy has the property that it can move to another place by way of propagating in certain media.
Not only that, a sound can also be reflected and also absorbed. Below are some of the
properties of sound that must be understood.
1. Sound Can Travel Through Liquid, Gas,
and Solid Substances
Sound vibrations will propagate in the form of waves. Therefore, sound that can propagate is
called a sound wave. Sound waves can travel through solids, gases and liquids.
Sounds that can travel through solid objects usually occur and we find them in toys, such as toy
cell phones. As for the propagation of sound through liquid objects, we can find it when two
stones are pitted against each other in water. Then we can hear the sound that will be
produced.
The sound propagation will take place quickly through the air. Therefore, sound cannot be
heard in a vacuum, for example, in outer space. An astronaut who goes into outer space will
definitely not be able to hear sounds without using aids. They may be able to speak with the
aid of radio communication. Thus, sound can propagate if there is an intermediate substance
through which it passes. The denser or denser the medium is, the greater the speed of
sound.
2. Sound can be absorbed and reflected
It should be understood that sound can experience reflection or reflection. This happens
because sound is included in the longitudinal wave. When propagating to another place, sound
can hit objects that are around it. Sound that hits the surface of an object can be reflected
or absorbed. When the sound hits the wall, the sound will be reflected. That way,
the sound will experience reflection. Generally objects that are hard, shiny, and dense have
the property of reflecting sound.
If based on the distance of the sound source and the reflecting wall, the reflected sound can be divided into
three types, including:
a. Reflected Sound Amplifies Original
Sound
The first type of reflected sound is reflected sound which can strengthen the original sound.
Generally this occurs when the conditions between the sound source and the reflecting wall are not
too far away or approximately 10 meters.
b. Echo
Echo is a type of reflected sound that sounds less loud and not as clear as the original sound.
This type of reflected sound occurs because the reflected sound has been mixed with the original
sound. This causes this reflected sound to interfere with hearing. Usually the
echo occurs at a distance of between 10 and 20 meters. Reverberation can occur in concert
halls, cinema halls, or meeting halls. Therefore, to eliminate echoes in a building, sound
absorbing materials must be installed on the walls of the building.
c. Echo
Echo is a type of reflected sound that will be heard after the original sound. Usually the
echo will sound as clear as the original sound. This type of reflected sound occurs when the
distance between the sound source and the sound reflecting wall is far enough. Generally the
echo occurs at a distance of more than 20 meters. We can hear this echo if we scream in the
middle of a football stadium or on a hillside. Another type of reflected sound is reflected
sound which can strengthen the original sound. The nature of this reflected sound is that it
can amplify the original sound. For example, our voice when singing in the bathroom.
Meanwhile, objects that can absorb sound are called sound absorbers. These sound absorbing
materials, for example, styrofoam or cork, carpet, foam, and others. These materials are widely
used on the walls of music studios or recording studios. With this sound absorbing layer, loud
music sounds will not be heard from outside the studio. Not only that, the installation of
sound absorbers also aims to avoid echoes.
3. Sound can be refracted
One of the next properties of sound is that it can experience refraction or refraction. For
example, the phenomenon of lightning that will sound louder at night than during the day. This
happens because the upper air temperature during the day is cooler than the air temperature below.
Whereas at night it is the opposite.
4. Sound waves are included in
longitudinal waves
The next characteristic of sound is that sound is a longitudinal wave. That means,
longitudinal waves are waves that have a direction of propagation parallel to or the same as the direction
of the vibration of the sound itself. If the direction of sound is to the left, the sound will
also propagate to the left.
5. Sound Can Experiencing Flexion
The fifth property of sound is that sound can experience bending or commonly known as diffraction.
This happens because sound waves have a length in the range of centimeters to several meters.
So it makes it easier for sound waves to experience bending.
An example of the nature of this sound is when we hear the sound of a motorcycle or car passing around a
corner. Even though we haven’t seen the motorbike or the car yet, we can already hear the sound
produced from the car and motorbike.
6. Sounds Experiencing Mix
Sound can also experience a combination or interference which can be divided into two, namely constructive
interference or sound reinforcement and destructive interference or sound attenuation. For
example, when we are between two loudspeakers with the same frequency and amplitude, we will hear
alternating loud and weak sounds.
7. Sound Needs a Medium
The next characteristic of sound is that sound requires a medium to propagate. This is because
sound is a moving wave. Therefore, in its movement, earth waves need a medium or a conducting
medium.
Benefits of Sound Waves
In practice, sound waves that arise due to the presence of certain sound energy have various benefits for
human life. Below are some of the benefits of sound for human life.
1. To check the content using ultrasound
(USG)
Who doesn’t know about ultrasound? Surely almost everyone knows, especially for pregnant women
and married couples. Ultrasound is a tool that is usually used to observe the development of a
baby in the womb or uterus. The way ultrasound works is by utilizing ultrasonic waves.
The ultrasound device will emit ultrasonic waves into the uterus of the pregnant woman.
It then tracks changes in the frequency of the reflected sounds of the beating heart and flowing
blood. Not only that, ultrasound is also used to detect tumor tissue growth, brain conditions,
and so on.
2. Ultrasonic therapy
Ultrasonic waves are also commonly used in the health sector. Which is generally used for
therapy. This is usually known as ultrasonic therapy. This type of therapy is used
to relieve pain in the joints and muscles.
3. Ultrasonic Testing
We can see ultrasonic testing in everyday life. For example, in the industrial sector which
utilizes ultrasonic waves for the milk homogenization process. Not only that, ultrasonic waves can also be
used in the field of pest control which will have a depressing effect on rats and cockroaches.
4. Ultrasonic Cleaner
The dishwasher is an example of an object that utilizes ultrasonic waves. Where water and
detergent will be vibrated by ultrasonic vibration and the particles can rub dirty dishes and clean them at
the same time.
5. Sonars
Juice ultrasonic waves are often used in sonar. For example, the use of ultrasonic waves by
ships is used to determine the depth of the seabed. The workings of these waves are carried out
based on the concept of sound reflection. Where at the bottom of the ship, there will be a tool
that can convert electrical energy into ultrasonic waves. Then it will be emitted to the
seabed. The sound waves originating from the ultrasonic waves will then propagate straight down
to the seabed. When the waves reach the seabed, some of the waves will be reflected back to the
ship, where they will be captured by the detector.
Those are some explanations about the nature of sound, understanding, types, and also the benefits of sound
for everyday life. Hope it is useful.