What Happens When Objects Vibrate to Make Sound?
A sound is a form of energy that can be produced by vibrating any object. For instance, if two vocal cords present in the human body or any other organism may get vibrated with the help of airflow, then a sound will come out. The sound can be produced by using three mechanisms. Namely - respiration, phonation, and articulation. All these are concerning human beings. This may vary from organism to organism, but the final way to produce sound is by only using the vibration of an object. Now we are going to learn what are the various vibrating objects to produce sound.
Sound is Produced by Vibration
Yes, Vibrating bodies produce sound. Let see how is a sound produced? Whenever the vibrating body moves in one direction, the aid undergoes compression, which is moving in the opposite direction. Whereas if the object moves in the opposite direction, it gets released freely, which leads to expansion. These expansion and rear fractions lead to the formation of longitudinal waves. For one longitudinal wave, it requires one compression and one expansion. Hence the air molecules more back and forth, the formation of more refractions and expansions take place. It helps in the formation of several longitudinal waves.
Intensity and Pitch
Intensity and pitch are two different factors that play a predominant role in producing sound.
If the pitch of the vibrating body is high, the sound can be produced with high frequency. Whereas if the pitch is low, the frequency of sound is also low. These both are directly proportional to each other.
The next one is intensity. It is defined as the amount of energy released from the object in a unit area's unit time. It can be calculated in the SI system, watts per square meter. The intensity also has an impact on the loudness of the sound. It is also directly proportional but slightly varies from the picture. If the intensity is more, the loudness will be high—similarly, vice versa.
The intensity can be measured in decibels. There is a logarithmic relation between the intensity and loudness of the sound. The following equation can represent it and is denoted by β, a Greek letter.
β = 10 log I/ I0
Where,
β is the intensity in decibels,
I is the sound intensity, and
I0 is the intensity of the threshold of hearing.
Examples of Sound Produced by Vibrations
Let us consider an example that gives a clear idea about how sound is produced by vibrations in physics.
One of the simple and best examples of sound produced with vibrating objects is the guitar. If we observe the guitar, some parallel strings will be there. Here the air is the medium. It helps to produce sound when we create vibration among the strings.
[Image will be Uploaded Soon]
Another well-known example is the tuning fork. It also explains how sound is produced with vibrating objects. The tuning fork is like the handle with the two tunes. Suppose we hit the tuning fork with the rubber hammer. In that case, it creates vibration among the two tines as the air molecules surrounded by the tuning fork get disturbed and undergo compression or expansion according to the tines' reaction. If we hit Victor the rubber hammer multiple times, they keep on undergoing either compression or expansion, which results in the formation of multiple waves. These waves lead to the propagation of sound. The append soundwaves can be transmitted with the help of pressure waves available in the object itself. In this way, the sound can be produced by the vibrating objects as far as we can apply some force on the medium or object.
[Image will be Uploaded Soon]
Conclusion
Hence we came to know the vibration of objects can produce that sound. Whether it is a human being or a substance or an object, A vibration is the only major source that can produce sound with different frequencies. It can be influenced by objects, targeting surface, medium, etc. We have several laws and a formula to calculate the sound's wavelength, frequency, intensity, etc. It has different properties like reflection, refraction, etc., based on the object. Hence the sound is a vast topic that everyone should understand adequately.
FAQs on How Sound Is Produced by Vibrating Objects
1. What is the fundamental principle behind how all sounds are made?
The fundamental principle is that sound is produced by vibrating objects. An object must vibrate, meaning it must move back and forth rapidly, to create a sound wave. This vibration disturbs the particles of the surrounding medium (like air, water, or solids), causing them to vibrate as well and pass the energy along as a wave until it reaches our ears. Without an initial vibration, there can be no sound.
2. What are some everyday examples of objects producing sound through vibration?
Many objects in our daily lives produce sound through vibration. Here are a few examples:
Musical Instruments: The strings of a guitar, the skin of a drum, and the air column inside a flute all vibrate to produce musical notes. You can learn more about how a guitar instrument works on this principle.
School Bell: When a bell is struck with a hammer, the metal body of the bell vibrates rapidly, creating a loud ringing sound.
Human Voice: Our vocal cords in the throat vibrate as air from the lungs passes over them, allowing us to speak or sing.
Buzzing Bee: The sound of a buzzing bee is caused by the rapid vibration of its wings.
3. How does a school bell produce such a loud sound when it is struck?
When a school bell is struck by a hammer, the kinetic energy from the hammer is transferred to the bell, causing its metal body to vibrate rapidly. These vibrations are typically large and forceful. The vibrating surface of the bell pushes and pulls on the surrounding air particles, creating strong areas of high pressure (compressions) and low pressure (rarefactions). This powerful disturbance travels outwards as a sound wave, which we perceive as a loud ring.
4. How do humans produce different sounds like speaking and singing?
Humans produce sound using the larynx, or voice box, located in the throat. Inside the larynx are two vocal cords. When we speak or sing, air from our lungs is pushed through the vocal cords, causing them to vibrate. The pitch of the sound is changed by muscles that adjust the tension and thickness of the vocal cords—tighter cords vibrate faster to produce a higher pitch, while looser cords vibrate slower for a lower pitch. The final sound is then shaped by our tongue, lips, and mouth. You can explore more about sound produced by humans to understand this process better.
5. What is the difference between sound produced by regular and irregular vibrations?
The nature of the vibration determines the type of sound we hear:
Regular Vibrations: When an object vibrates in a consistent, periodic, and uniform pattern, it produces a pleasant sound called a musical sound or a tone. Examples include the notes from a flute, violin, or a tuning fork.
Irregular Vibrations: When an object vibrates in a random, non-periodic, and inconsistent manner, it produces an unpleasant sound called noise. Examples include the sound of a hammer hitting a wall, traffic sounds, or a plate breaking.
Thus, the key difference lies in the predictability and consistency of the vibration pattern.
6. If all sound comes from vibration, why can't we see most objects vibrating when they make a sound?
We cannot see most objects vibrating because their vibrations are often too fast and too small for the human eye to perceive. The characteristics that determine this are:
Frequency: The number of vibrations per second. Most sounds we hear are produced by objects vibrating hundreds or thousands of times per second, which is too fast for our eyes to follow.
Amplitude: The maximum displacement of the vibrating object from its rest position. For many sounds, the amplitude in physics is microscopic, meaning the object moves back and forth by an incredibly small distance that is not visible.
Only objects with slow, large-amplitude vibrations, like a ruler flicked at the edge of a table, are easily visible.
7. How does the vibration of an object actually travel through the air to reach our ears?
A vibrating object acts like a piston, pushing and pulling on the surrounding air particles. As the object moves forward, it compresses the air particles in front of it, creating a region of high pressure called a compression. As it moves backward, it leaves a space with fewer particles, creating a region of low pressure called a rarefaction. This process repeats, creating a chain of compressions and rarefactions that travel away from the source as a longitudinal wave. This wave, which is the propagating disturbance, is what we call a sound wave. For this to happen, sound needs a medium for propagation; it cannot travel in a vacuum.
8. Why is sound classified as a mechanical wave?
Sound is classified as a mechanical wave because it requires a physical medium (like a solid, liquid, or gas) to transfer energy. The vibrations from the sound source need to be passed from particle to particle. Without particles to vibrate, the sound cannot travel. This is why there is no sound in the vacuum of space. In contrast, electromagnetic waves like light do not require a medium and can travel through a vacuum.
9. Do all vibrating objects produce a sound that humans can hear?
No, not all vibrating objects produce a sound that humans can hear. The ability to hear a sound depends on its frequency, which is measured in Hertz (Hz). The range of human hearing, known as the audible and inaudible sound range, is typically between 20 Hz and 20,000 Hz.
Infrasound: Vibrations below 20 Hz are inaudible to humans (e.g., some earthquake waves).
Ultrasound: Vibrations above 20,000 Hz are also inaudible to humans but can be heard by animals like dogs and bats.
Therefore, an object can be vibrating, but if its frequency is outside this range, it will produce no perceptible sound to us.
10. What is resonance, and how does it make a sound from a small vibration much louder?
Resonance is a phenomenon where an object is forced to vibrate at its own natural frequency by an external vibrating source. When this happens, the amplitude of the vibration increases dramatically, resulting in a much louder sound. For example, when a single vibrating guitar string is plucked, its sound is faint. However, the vibrations from the string cause the large, hollow wooden body of the guitar to vibrate at the same frequency (this is called forced vibration). Since the guitar body's shape is designed for resonance, it vibrates with a very large amplitude, moving much more air and producing a loud, rich sound.
