10 Surprising Facts About Sound

The term “sound” refers to what is heard when sound waves travel through a medium to the ear. When the vibrating air molecules reach our ears, they cause the eardrum to vibrate as well. The bones of the ear vibrate in the same way as the object that caused the sound wave to begin. These vibrations allow you to hear various sounds.

1. Sound is created when something vibrates and sends waves of energy (vibration) into our ears. The vibrations travel through the air or another medium like solid, liquid, or gas to the ear is what we call sound. The stronger the vibrations, the louder the sound will be. Sounds get fainter the further you get from the sound source.
2. On Aug. 27, 1883, in the morning the eruption of the Krakatoa volcano in Indonesia made the loudest sound known to the history of mankind — a terrifying roar that sent sound waves around the world four times and was heard 3,000 miles away on the island of Rodrigues in the Indian Ocean.
3. Sound can travel in the air at approximately 332 meters per second. This is fast but not nearly as fast as light which travels at 300 000 kilometers per second. This difference in speeds means that sound takes time to travel.
4. Sound travels more easily in liquids and solids as the molecules in these are denser than air. The sound in water can travel at a speed of 1480 meters per second.
5. Sound does not travel at all in space. The vacuum of outer space has essentially zero air. Because sound is just vibrating air, space has no air to vibrate, and therefore no sound can be heard in space. Radio is a form of electromagnetic radiation just like light and can therefore travel through the vacuum of space just fine.
6. The human hearing range is from 20 Hz to 20 kHz (20 to 20000 vibrations per second), whereas the dolphins have one of the strongest hearing abilities.
7. The hearing range of dolphins is 20Hz to 150 kHz, which is five times more than dogs.
8. The blue whale, the largest animal on earth, can produce the strongest sound by any other land or marine animal. The sound of a blue whale can reach up to 188 dB and can be heard from 500 miles underwater. The sperm whale can produce sounds reaching 230 dB.
9. A lion roar can be heard from 8 km away and could reach 114 dB. Whereas the normal speaking pitch of humans is about 30dB and can scream up to 100 dB. The world record for shouting is been held by Annalisa Wray from Northern Ireland since 1994. Her Scream was ear-piercing 129 dB.
10. Bats use a special technique called echolocation. They listen to echoes of their ultrasonic calls. They use this technique to avoid obstacles and find food.