Attention Getting Question:
How do movements make sound?
Energy is the ability to cause motion or create change in matter. Sound is a form of energy that carries vibrations through solids, liquids, and gases. Vibrations, or movements that go up or down, are what make all sounds. The energy in a vibration is transferred through matter in a wave.
Sound waves travel through solids, liquids, and gases. Sound bounces off the particles in different forms of matter as it travels. Think about how the particles are spread out in a gas. When sound goes through a gas, some of the sound is lost because the particles are far apart. If you are talking to your friend outside on a windy day, you have to speak louder in order to be heard. Did you know that sounds travel faster through water and even faster through solids? It’s because the particles in liquids and solids are closer together than they are in gases.One way to explore sound through a solid is to make a cup and string phone. When the string is tight, the sound will travel through the string, which is a solid.
How do you hear sounds? When a sound is made, the sound waves travel to your ear. Your eardrum vibrates when a sound is heard. There are tiny bones and liquid behind your eardrum that also vibrate with sound. Auditory or hearing nerves then carry those vibrations to the brain and interpret the sound. So, if you’re riding your bike and the sound wave of a car behind you travels through the air to vibrate your eardrums, your auditory nerves will carry the vibrations to your brain. Your brain will then recognize the sound as a car so you can safely move out of the way.
Scientists and engineers study the properties of sounds. If you want to know how loud or soft a sound is, you can measure the amplitude. Decibels (dB) are the unit of measurement for amplitude. A car passing on the street is around 70 dB.Leaves rustling in the wind are around 20 dB.Sounds above 120 dB are painful to your ears. So, if you’re ever within 100 feet of a jet engine, you’ll need to protect your ears. Jet engines measure at 150 dB.
Another way to study sound is by measuring the frequency of sound. The frequency measures how high or low a sound is or the pitch of the sound. Frequency is measured by counting the number of wavelengths that pass by a particular point in a given length of time. Low sound frequencies have wavelengths that are farther apart. Sound waves that are closer together have higher frequencies. The unit of measurement for frequency is the hertz (Hz).The human ear can hear frequencies ranging from 20 Hz to 20,000 Hz.
You know that sound is energy. Scientists are working on using sound energy as an alternative energy source by developing a way for the sound vibrations to be converted into electricity. Imagine being able to charge your cell phone by talking on it. In the future, sound energy may be used as a way to conserve our natural resources!
Sound is a form of energy that carries vibrations through solids, liquids, and gases. Vibrations are movements that go up or down. Amplitude measures how loud or soft a sound is while frequency measures how high or low a sound is. Think about the sound energy that is all around you right now!