Definition of Echo and Reflected Sound – In everyday life, did Readers ever realize that all sounds that Readers can hear actually have the ability to reflect?
Just like a basketball being bounced off a wall, sounds that can be produced by anything including humans, animals, plants, and also inanimate objects also have the ability to bounce, it’s just that the reflected sound has no form because sound also has no exist, right? Readers needs to know that sound is also a form of energy that can be utilized in human life.
Then, what are the kinds of reflected sounds? Come on, let’s look at the following article so that Readers can understand reflected sounds better!
What Is Meant By Sound?
Before discussing the types of reflected sounds, Readers needs to first understand the meaning of the sounds. Sound and sound actually have the same meaning. Sound can be produced by all things including humans, animals, plants, and even inanimate objects around.
According to the Big Indonesian Online Dictionary, sound means something that can be heard by the human ear. If illustrated, sound has a wave-like shape. As previously explained, sound is also a form of energy. Sound energy generally comes from vibrating objects and vibrations can propagate.
The definition of sound is a longitudinal wave that propagates tightly and at the same time tenuously formed by air molecules and can be generated from a sound source that is capable of vibrating. From the propagation of the sound will later be heard by the ear and in the end can be understood by the brain.
In general, sound can be measured using Hertz (Hz) units, and the loudness of sound can be measured using decibel units.
What Is Sound Energy?
Sound energy is all abilities that arise as the influence of sound.
When Readers is talking, he must make a sound, or when he doesn’t intend to make a sound, he can still make a sound, for example when he runs, hits, and opens a door. Well, of course all of these sounds are produced by a sound source.
Sound sources are all objects that have the ability to be able to produce a sound and have various types because not all sounds can be produced by just one source. An example is the ukulele, the source of the sound is in the form of strings. In addition, the workings of sound sources to be able to produce a sound also have various kinds.
Discussion about sound sources will not be far from resonance. Resonance is the vibration of an object caused by another object, so that the sound produced becomes louder and stronger. The existence of this resonance is generally used for musical events, using a resonator.
The existing sound has several characteristics, namely strong, weak, shrill, and low pitch.
Based on the frequency, sound can be divided into 3 types, namely:
Infrasound is a sound that is classified as weak because it has a number of sound vibrations of less than 20 Hz per second. The human ear is generally unable to hear infrasound, only certain animals can hear it, such as cats, crickets, dogs, and so on.
Audiosonics is a type of sound that has a number of vibrations of approximately 20-20,000 Hz per second. With this number of vibration sizes, audiosonic sounds can reach and be heard by the human ear.
Ultrasonic is a type of sound whose frequency is very strong, and its level is above audiosonic sound. The number of sound vibrations is more than 20,000 Hz per second. However, even though the ultrasonic sound has a strong vibration, the human ear is unable to perceive and hear it. Just like infrasound, ultrasonic sound can only be heard by certain animals. For example, like bats and dolphins.
Kinds of Reflective Sounds
Readers must know that reflected sound is sound that is created as a result of a sound wave hitting a reflective plane and then the sound wave is reflected back. There are three types of reflected sound, namely echo, echo, and amplify the original sound.
1. Echo Sound
Echo sound is a type of reflected sound that occurs after the original sound. This means that the sound of the reflected sound will be heard with a short pause after the original sound has been created. Echoes can occur because there is a considerable distance between the sound source and the reflecting wall.
In contrast to the echo type of reflected sound, this echo sound often occurs on hillsides, cliffs, caves, and soccer stadiums. The similarity of these places is that the distance between the reflecting walls is more than 20 meters. For example, when Readers is in a cave, when Readers shouts “Hi”, then the reflected sound of the word “Hi” will come out after the original sound is no longer heard.
An echo sound is a type of reflected sound that sounds as if it is not clear, even the clarity is not the same as the original sound. This echo sound can occur as a result of mixing the original sound with the reflected sound.
Reverberation generally occurs at a distance between reflective walls of about 10 to 20 meters, such as inside buildings, such as cinemas, concert halls and conference halls.
For example, when Readers is watching a concert from a singer he likes, then the singer shouts the word “Biar”, later as a result of the echo sound, Readers will listen to the word “Biar” with a pause. Here’s an illustration:
Original sound: bi – ar
Reflected sound: bi — ar
Sounds heard: Let ———— ar
3. Amplify Original Sound
The next type of reflected sound is that which has the properties of amplifying the original sound. In contrast to the type of reflected sound that has been described, in this type the reflected sound will actually become an amplifier for the original sound, this can happen because the distance between the sound source and the reflecting wall is close enough, so the time needed by the sound to reflect back the sound also tend to be shorter.
Therefore, this type of reflected sound will be heard and considered at the same time as the original sound. The original sound can actually sound louder, generally this happens when Readers sings in a small closed room like a bathroom.
Whether the sound is strong or not depends on several factors, namely:
- Amplitude (maximum deviation of a wave that will affect the sound strength) of the sound source
- The distance between the sound source and the listener
- The distance between the listener and the reflecting wall
Benefits of Reflected Sound:
- Can be used to measure the depth of the sea, especially in ultrasonic sound.
- To detect the fetus in the womb, usually using infrasound.
- To detect damage to a metal.
- There are speakers on the radio, television, to cell phones. Usually using audiosonic sound.
- For the search for ships or metal treasures on the seabed.
Properties of Sound Energy
Sound energy has special properties, namely it can move to another place, by propagating in certain media. Not only that, sound can also be absorbed and can be reflected.
1. Sound Can Travel Through Liquids, Gases, and Solids
Many think that sound can only travel through solids, when in fact, sound can also travel through gases and liquids.
The vibrations created by sound will propagate through the waveform. Therefore, the propagation is called a sound wave. Well, these sound waves can propagate through liquids, gases, and solids. Even the fastest propagation is when through the air. An example is when ringing the gong.
- Through solid objects, for example when playing a can phone using strings and cans. Sound waves will propagate through the strings to the end of the phone and up to the ear.
- Through liquid objects such as when a rock falls into water
- Through gaseous substances, for example when there is thunder in the rainy season
You also need to know, Readers , that sound cannot propagate in a vacuum. A vacuum is a room that has no air in it.
2. Sound Can Be Absorbed and Reflected (Reflection)
When sound waves propagate in solid objects and the surface of these objects, the sound will be absorbed and even reflected. For example, if sound hits the surface of a cave, it will reflect and create an echo.
3. Sounds Can Experience Refraction (Refraction)
Not only light can experience refraction, but also sound. This is because light and sound both have waves, where the main characteristic of the wave is refraction.
An example of sound refraction is when the sound of thunder sounds louder at night than during the day.
This can happen because during the day, the upper layer of air tends to be colder than the lower layer. Therefore, the speed of sound propagation becomes smaller in cold temperatures when compared to hot temperatures, thus making the speed of sound in the upper layers of air smaller than that in the lower layers.
4. Sound Can Experiencing Flexion (Diffraction)
Sound waves are very easy to experience bending or diffraction because sound waves in the air have wavelengths in the range of centimeters to several meters.
An example of this sound diffraction is when Readers can already hear the sound of the engine of a vehicle at the corner, even though Readers has not seen the vehicle because it is blocked by the buildings around the corner.
5. Sounds Experiencing Mixture (Interference)
It turns out that sound waves can experience symptoms of combination or interference. Well, this interference is divided into two types, namely constructive interference (sound amplification) and destructive interference (sound attenuation).
An example of sound wave interference is when Readers is between two loudspeakers with the same frequency and amplitude, then later Readers will hear alternating loud and weak sounds.
Even though anyone and anything can produce sound, in order for it to be heard by human ears and animal ears, it also requires several conditions, namely there must be a medium, a source of sound, and a listener.
1. There is Medium
Previously, it was explained that sound can travel through solid, liquid, and gas objects. Well, these objects can become a medium for sound propagation to occur. Therefore there is a statement that sound cannot be produced in a vacuum.
The existence of the medium also influences the speed of sound. An example is the sound of thunder. The sound of thunder can be caught by human and animal ears because it propagates through the air. If the air has a temperature of around 20०C then the speed of sound is 343 m per second.
Another thing if the medium is a liquid, then the speed of sound is around 1,500 m per second. The speed of sound is generally used to search for treasure or ships that have sunk on the seabed.
Then in the medium in the form of solid objects, especially steel, the speed of propagation is around 6,000 m per second. This experiment on the speed of propagation of sound in a solid medium can be done simply by tapping the table with a pencil.
2. There is a Sound Source
The source of the sound is the vibration of the object that produces the sound. If Readers’ ear is closer to the sound source, the sound will be clearer and louder. Examples of sound sources are the sound of a guitar coming from plucked strings, the sound of a drum coming from animal skins being beaten, and so on.
3. There is a Listener
So, those who can hear various sounds around Readers are humans and animals. How can sound be heard? Namely by relying on the sense of hearing in the form of ears.
- Tone is a sound that has a regular frequency
- Wheezing is a sound that has an irregular frequency
- Timbre, namely the color of the sound, which is in the form of the overall auditory impression obtained by the ear of Readers from the sound source.
- A boom is a sound that has a large amplitude and is heard suddenly.
Benefits of Sound for Human Life
The presence of sound is of course very beneficial for human life in various fields, even including in the health sector though. So, here are the benefits of sound:
- Detects the presence of tumors in the human body.
- Destroys kidney stones in the human body.
- Ultrasound (Ultrasonography), which is a method for detecting a fetus in a mother’s womb. In this case, it will usually use ultrasonic waves.
- To measure the depth of the sea, detect the presence of mines, search for sunken ships, and locate fish groups using SONAR (Sound Navigating Ranging) tools.
- To detect the oil and mineral content in the earth, especially using ultrasonic waves.
- To measure the length of cave passages and investigate metal damage, using sound reflection.
- Tones sung by humans can be used to study the expression of human thoughts, motivations and emotions.
Well, that’s an explanation of the types of reflected sounds and the benefits of sound for everyday human life. Even though sound is closely related to Readers’ life , without realizing it, it turns out that the existence of sound is very useful