# What happens to the energy of the sound wave as it moves away from the source?

## What happens to the energy of the sound wave as it moves away from the source?

Sound vibrations, then, travel outwards in all directions in waves from a sound source. As they travel outwards the energy they contain becomes dissipated and therefore the sound becomes weaker the further it is from the source.

## What else can make sound fainter?

Two things are happening: Sound spreads in a sphere, like a balloon that gets inflated. As the sound spreads over a larger area the sound gets fainter. This will cause the sound to go lower and lower but also to sound fainter.

How does the intensity of a sound wave change if the distance from the source?

As a sound wave carries its energy through a two-dimensional or three-dimensional medium, the intensity of the sound wave decreases with increasing distance from the source. The intensity varies inversely with the square of the distance from the source.

### How does movement affect sound?

A fast moving vehicle or sound source will demonstrate a change in frequency/pitch as it passes an observer. As the firetruck passes and moves away, a drop in pitch will be heard (observer B) because the wave crests are arriving less frequently. The Doppler effect describes the changing pitch of the siren.

### Why does the sounds become weaker or fainter as it moves away from the observer?

The wave gets smaller because it spreads out (spreading loss) and because some of the sound energy is absorbed by seawater.

How does sound decrease with distance?

For every doubling of distance, the sound level reduces by 6 decibels (dB), (e.g. moving from 10 to 20 metres away from a sound source).

#### How does distance affect sound?

As distance from the sound source increases, the area covered by the sound waves increases. The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source.

#### When a light or sound source moves toward you is there an increase or a decrease in the wave speed?

When the source moves toward you it is still emitting a wave every 5 seconds but because the speed of sound is relatively constant and the moving source can not increase the speed of sound it causes an increase in frequency when moving toward you by “chasing” the previous wave emitted, effectively reducing the distance …

Why does a sound sound fainter as you move away from its source?

Sound grows more faint as you move away from the source for two reasons: attenuation and diffusion. Sound energy attenuates as it passes through a medium, until eventually all the sound energy is lost to friction. So the further away you are from the source, the more the sound has attenuated before reaching you. .

## How does distance from a sound source affect how loud it will?

As you move away from the clock, the alarm sounds quieter, so our distance from the source of a sound will affect how loud it seems. After viewing the clip, ask the children to sit at one end of the classroom. Put a loudly ticking clock at the opposite end.

## Why does sound become softer when the noise is further away?

As you are moving away from the source of the sound it takes more and more time between the arrival of the start of a soundwave and the end of a soundwave. This will cause the sound to go lower and lower but also to sound fainter. Originally Answered: Why does a sound become softer and finally dies out as we move away from its source?