Every time a sound is made, there is some vibrating object somewhere. Something is moving back and forth rapidly. Sound starts with a vibrating object.
But sound must travel in something. It requires something to carry the sound from its source to the hearer. This is called “a medium.” A medium can be practically anything-air, water, objects, even the earth. The Indians used to put their ears to the ground to hear a distant noise!
No medium-no sound. If you create a vacuum, space containing no air or any other substance, sound cannot travel through it. The reason for this is that sound travels in waves. The vibrating objects cause the molecules or particles in the substance next to them to vibrate. Each particle passes on the motion to the particle next to it, and the result is sound waves.
Since the mediums in which sound travels can range from wood to air to water, obviously the sound waves will travel at different speeds. So when we ask how fast does sound travel, we have to ask: In what?
The speed of sound in air is about 1,100 feet per second (750 miles per hour). But this is when the temperature is 32 degrees Fahrenheit. As the temperature rises, the speed of sound rises.
Sound travels much faster in water than in air. When water is at a temperature of 46 degrees Fahrenheit, sound travels through it at about 4,708 feet per second, or 3,210 miles per hour. And in steel, sound travels at about 11,160 miles per hour!
You might imagine that a loud sound would travel faster than a weak sound, but this isn’t so. Nor is the speed of sound affected its pitch (high or low). The speed depends on the medium through which it is traveling.
If you want to try an interesting experiment with sound, clap two stones together when you are standing in the water. Now go under water and clap those two stones together again. You’ll be amazed how much better sound travels through water than through air!
