What is sound?
What is sound?
Simply, sound is a form of energy made by vibrations. Vibrations are back and forth movement of particles around us, such as air particles. The vibrations cause the particles to bump into another particle, which causes that particle to bump into another one until all the energy is used up. The movement made by these vibrations is called a sound wave.
Sound waves are formed by compressions and rarefactions. Compressions are formed when the particles are close together while rarefactions are formed when particles are far apart.
Sound waves can be shown in two ways: one showing waveforms and another showing compressions and rarefactions.
Simply, sound is a form of energy made by vibrations. Vibrations are back and forth movement of particles around us, such as air particles. The vibrations cause the particles to bump into another particle, which causes that particle to bump into another one until all the energy is used up. The movement made by these vibrations is called a sound wave.
Sound waves are formed by compressions and rarefactions. Compressions are formed when the particles are close together while rarefactions are formed when particles are far apart.
Sound waves can be shown in two ways: one showing waveforms and another showing compressions and rarefactions.
Properties of Sound: pitch and amplitude
What is pitch and amplitude?
First, let's figure out what a wavelength is. Wavelength is the distance between one point of the wave to the same point in the next wave. Pitch is how high or low the sound is. It depends on the wavelength. The longer the wavelength, the lower the pitch -- the shorter the wavelength, the higher the pitch. You can also look at the frequency of the wavelength. The more wavelengths produced in a given amount of time, the higher the pitch. The illustration on the left tells us that the pitch is different BUT the amplitude is the same. Amplitude is the amount of energy in a sound wave. The greater the amplitude, the louder the sound. The illustration on the left tells us that the amplitude is different, but the pitch is the same. The illustration on the left puts together what you have just learned... |
How fast does sound travel?
What is the speed of sound?
Well, it depends on which state of matter -- solid, liquid, or gas -- it is travelling in. Since sound travels through the vibrations of particles, bumping each other to transmit the sound energy, where do you think it will travel the fastest?
If you said SOLIDS, then you are right! Why? Take a look at the illustration to your left. Compare the particles of a solid, liquid, and gas. What is the main difference?
If you answered "the distance between the particles", then you are right again! The solid particles are very, very, very close to each other. This means that the particles can quickly transmit the sound vibrations.
Just how fast is the speed of sound?
Check out this table:
Well, it depends on which state of matter -- solid, liquid, or gas -- it is travelling in. Since sound travels through the vibrations of particles, bumping each other to transmit the sound energy, where do you think it will travel the fastest?
If you said SOLIDS, then you are right! Why? Take a look at the illustration to your left. Compare the particles of a solid, liquid, and gas. What is the main difference?
If you answered "the distance between the particles", then you are right again! The solid particles are very, very, very close to each other. This means that the particles can quickly transmit the sound vibrations.
Just how fast is the speed of sound?
Check out this table:
How do we hear sound?
As the saying does, the bigger your ear, the better you hear. Well, let's make that more specific. The bigger your pinna or outer ear is, the better you hear.
Why do you think this is?
Let's do an experiment. Listen to your surroundings for about 10 seconds. Next, cup your hands behind both outer ears. Listen again for about 10 seconds. Is there a difference?
You should be able to hear a bit better with your hands cupped behind each outer ear. This is because you have collected more sound waves. That is why bats (which are blind) have enormous ears compared to their body size. They "see" by listening to the echos of ultrasonic (super high pitched sounds) that they send out. This is called echolocation.
Why do you think this is?
Let's do an experiment. Listen to your surroundings for about 10 seconds. Next, cup your hands behind both outer ears. Listen again for about 10 seconds. Is there a difference?
You should be able to hear a bit better with your hands cupped behind each outer ear. This is because you have collected more sound waves. That is why bats (which are blind) have enormous ears compared to their body size. They "see" by listening to the echos of ultrasonic (super high pitched sounds) that they send out. This is called echolocation.
Bats are blind creatures. To find their way around, they send out ultrasonic or high pitched sounds from their mouths or noses. The sound travels until it hits an object. When this happens, the sound echoes or returns to the source. The bats enormous ears pick up the echo. They can determine the distance of the object by the amount of time it takes the sound to get back to them. This is called ECHOLOCATION. Amazing, isn't it? |
How about humans? How do we hear sounds?
Sound vibrations are collected by the pinna or outer ear. Sound vibrations travel through the ear canal and then hits the ear drum. This causes the ear drum to vibrate... ...which in turn causes the hammer (malleus), anvil (incus), and stirrup (stapes) to move as well. By the way, the hammer, anvil, and stapes are the three smallest bones of the human body. Together, they are called ossicles. The ossicles transmit the vibrations to the cochlea (the spiral shaped part of the inner ear). Inside the cochlea, the fluid and cilia (really tiny hair) move sending the vibrations to the auditory nerves. The auditory nerve sends the signals to the brain which interprets the sound vibrations into something we understand. And all these, sound vibrations travelling from the pinna to the brain, happen in a split second! |
Making sound
Now that we know what sound is and how we hear, let's make sound using everyday items around us!
Gigamind's P4 classes were given sound tubes, drinking straws, glass containers, plastic water, chopsticks, metal spoons, and water to produce sound. They also experimented on how to change the pitch of their "instruments"!
The students discovered that the amount of water can change the pitch of their glass xylophone and plastic bottle blower bu in very different ways! With the plastic bottle blower, more water in the bottle raised the pitch. With the glass xylophone, more water in the glass containers decreased the pitch.
Why is this so? Share your ideas with me by completing the form below!
The students were also able to change the pitch of their drinking straw kazoo. How do you think they did it? Again, share your ideas with me by completing the form below!
That's it, boys and girls! Until the next science workshop, enjoy some of the photos and videos of your class!
Gigamind's P4 classes were given sound tubes, drinking straws, glass containers, plastic water, chopsticks, metal spoons, and water to produce sound. They also experimented on how to change the pitch of their "instruments"!
The students discovered that the amount of water can change the pitch of their glass xylophone and plastic bottle blower bu in very different ways! With the plastic bottle blower, more water in the bottle raised the pitch. With the glass xylophone, more water in the glass containers decreased the pitch.
Why is this so? Share your ideas with me by completing the form below!
The students were also able to change the pitch of their drinking straw kazoo. How do you think they did it? Again, share your ideas with me by completing the form below!
That's it, boys and girls! Until the next science workshop, enjoy some of the photos and videos of your class!
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Try this sound test!
As we grow older, our hearing degenerates (becomes weaker). Do you believe that there are sound frequencies that YOU can here but your teachers or parents (adults in general) cannot?
Try this out BUT DO NOT USE HEADPHONES!!! Listen with the whole family and see up to which level your parents and you can hear!
Share the results with me through email. Just click the button below!
Have fun!
As we grow older, our hearing degenerates (becomes weaker). Do you believe that there are sound frequencies that YOU can here but your teachers or parents (adults in general) cannot?
Try this out BUT DO NOT USE HEADPHONES!!! Listen with the whole family and see up to which level your parents and you can hear!
Share the results with me through email. Just click the button below!
Have fun!