Sound and Its Properties

Sound and Its Properties

Open Ended

What sounds make you happy? What sounds make you sad?

Sound is a form of energy.

Vibrations produce sound which travels through solids, liquids, or gas.

Animals make use of sounds to communicate.

Human beings can hear sounds from 20 Hz to 20,000 Hz.

Many animals can hear beyond that.

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Sound

Sound is produced by vibrations

String instruments like guitars produce sound when their strings are strummed

When something vibrates, it moves the surrounding medium, like air, and carries the sound to our ears.

The force of the vibration creates a sound wave.

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How Sound is Produced

Multiple Choice

Sound can travel when there is no air.

• True

• False

Multiple Choice

Humans can hear sounds from 20 Hz to 20,000 Hz.

• True

• False

Sounds differ because of their properties.

Different materials can create various noises, and that is why musical instruments are so diverse.

People of the same age have widely different voices

The properties that affect sound are: pitch, volume, and frequency.

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Properties of Sound

Sounds can be low or high pitched.

High-pitched sounds are produced by objects that vibrate very fast.

Low-pitched sounds are made by objects that vibrate slowly.

Harmony is produced in music when different pitches come together to create pleasing sound.

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Pitch

It is the softness or loudness of sound.

Volume is measured in "decibels".

Loud sounds which are unpleasant are called "noise".

Noise pollution is the harmful or annoying levels of noise specially in the city.

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Volume

The number of times that sound waves vibrate is the frequency.

High-frequency sounds have high-pitch, and conversely, low-frequency means low-pitch.

Sound waves can also be deflected or bounce on objects.

An echo occurs when sound waves bounce back towards the source.

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Frequency