Sound and distance

In a nutshell

A sound source is an object that produces a sound. Sounds get quieter as you move further away from the sound source.

Sound source

Definition

A sound source is an object that is producing a sound.

Example

For music playing from a radio, the radio speakers are the sound source.
When speaking, your vocal cords are the sound source.

Sound and distance

Sounds get fainter as you move away from the source of the sound. As the sound wave travels through more and more particles it loses energy. This makes the vibrations weaker as the distance from the sound source increases.

Sound also get fainter because some of the vibrations are absorbed by the obstacles they meet.

Example

You have to shout to get the attention of someone far away. But you can talk at a normal volume to someone standing next to you.