Continue with Microsoft TeamsHearing Sounds
Vocabulary
Read the vocabulary terms to understand the reading better.
Decibels
Decibels (dB) are used to measure how much energy is in sound.
Hertz
The pitch of sounds is measured in Hertz.
Pitch
Pitch is the way that noise may sound high or low.
Vibration
Vibration means to move back and forth very rapidly and steadily.
We hear with our ears. Our ears are special organs that pick up vibrations made by sound.
The ear is made up of three different sections: the outer ear, the middle ear, and the inner ear. These parts all work together with our brain so we can hear and understand sounds.
Most animals have ears that help them hear sounds. Animal ears come in many shapes and sizes. Most of the time, ears are found on an animal’s head. Some animals have hearing organs that do not look like ears. For example, crickets have small, pale spots on their front legs that sense sound. Snakes do not have an outer ear, but they do have an inner ear. Snakes also feel vibrations through the ground. These vibrations travel through a snake’s lower jaw, and into the inner ear.
Measuring Volume
Sounds can be loud or soft. This is called the volume of sound. Sounds that have more energy are louder. Sounds with less energy are softer. Decibels (dB) are used to measure how much energy is in sound. If you have good hearing, the softest sound you can hear is 0 dB. One of the loudest sounds ever heard was the eruption of a volcano in 1883. Scientists estimate that the sound was 180 dB. People 3000 km away from the volcano heard the eruption.
Measuring Hearing Range
People and animals can hear a range of sounds, from low-pitched sounds to high-pitched
sounds. The pitch of sounds is measured in Hertz (Hz). One vibration per second is one Hertz. Low-pitched sounds have lower values of Hertz. High-pitched sounds have higher values of Hertz.
People can hear sounds that range from 20 Hz to 20 000 Hz. Dogs can hear sounds that range from 40 Hz to 45 000 Hz. This means that dogs can hear sounds at a higher pitch than people can. Have you ever heard a dog whistle? The whistle makes a sound with a pitch that is too high for you to hear, but dogs can hear it.
The chart shows the lowest-pitched and highest-pitched sounds that people and various animals can hear.
To learn more about hearing sounds, watch the video by SciShow Kids on YouTube.
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