Sound

23.1 Sound travels away from the source
Sound also travels in a similar way. When an object produces a sound, the sound travels away from the object in all directions. The object producing the sound is called the source of the sound.
23.2 Sound requires a medium to travel
Sound requires a medium to travel. When an alarm clock rings, we can hear the sound because the sound travels through the air and reaches our ears, In this case, air is the medium through which sound travels.