Imagine a world without sound? Seems impossible! The fact that we can hear is a blessing to human kind. The reason we can listen to good music, enjoy conversations with friends or even speak- is sound. Sound is nothing but a vibration that propagates as an acoustic wave; that means anything that vibrates creates sound. Sound needs a medium to travel hence it can never propagate through vacuum. It travels in a pattern called waves and sends off waves of energy in to our ears. The quality of the sound is known as the pitch and it depends on the frequency of the vibrations.
There is plethora of interesting facts about the sound but we have compiled a list of top ten for you:
- Use of infrasound in horror movies
Did you know horror film makers make use of infrasounds? These sounds are used as they create anxiety, shivering and at times heart palpitations in us when played. This gives essence to horror movies which people watch to experience the thrill of it. Infrasound is below human hearing range and is also referred to as low frequency sound. Inaudible to humans, these sounds have frequencies below 20 Hz. Human ear senses low sounds as it is the primary sense organ for sound but these infrasound at higher intensities cause vibrations that can felt in different parts of the body. Hence a great tool to be used or horror movies.
2. Loudest natural sound on earth
Source: Wired
The loudest ever natural sound made on earth was that of a volcano eruption. August 1883 marked the event that made history. The volcano of the Krakota island bursted making a sound that was heard thousands of miles away. The sound circled the earth several times in all directions. It was heard in the Andaman and Nicobar Islands (1300 miles away from the eruption) as some gun firing sound; new guinea and western Australia (2000 miles away) also witnessed a series of loud sounds and even 3000 miles away in the island of Rodrigues near Mauritius. it was the loudest sound reported at 180 Db.
3. The study of sound and its production
Acoustics is the branch of physics that deals with the study of sound and its production. A researcher who studies it is known as an acoustician and someone who works in the acoustics technology is known as an acoustical engineer. Acoustics find its application majorly in making music. Other applications also include warfare, medicine, architecture and more.
4. Vibrating ears
Our ears vibrate similar to the sounds we hear as they are vibrations too. Vibrations enter through our outer ear causing the ear drum to vibrate too. Hammer, anvil and stirrup are the three tiny bones that are attached to the ear drum and vibrate too. These bones amplify the vibrations within the inner ear that are then picked up by the auditory nerve. These three bones are the smallest in our body and are pea sized put together.
5. Bats and their technique of echolocation
Source: Birdlife.org
Bats use a technique called echolocation by which they determine the location of the objects around. This is possible because of the sound objects reflect. This helps bats to move around even in the darkness and identify obstacles and enemies by this mind-blowing navigation technique. Bats generate these sounds in their larynx and emit them through their mouths. These sounds can have a frequency of upto 140 decibels (that would be similar to the sound of a jet engine 30 meters apart). Bats close their inner ears while making such sounds so they don’t go deaf. They can detect their prey up to 5 meters away and can even calculate its size and stiffness. They can also detect wires as thin as human hair.
6. Determining thunderstorms
Did you know you could actually tell how far is a thunderstorm from you? Since light travels faster than sound, we see lighting first and then hear the thunder. So when you see the lightning start counting 1-Mississippi, 2-Mississippi and so on till the time you hear the thunder. Divide your count by 5. The result is your answer to how far is the storm from you.
7. The Mabaans
The mabaan is a tribe in the South Sudan and is known for its hearing ability. The tribe is very quiet and peaceful and doesn’t use any guns or drums unlike nearby tribes. A study was conducted in the 1960’s by Samuel Rosen. It revealed that mabaan people could converse even being 300 feet apart from each other with their backs facing each other. They talked softly and were still able to hear. It was found that mabaans in their 70’s could hear far superior to that of Americans in their 20’s. their extraordinary hearing power is said to be due to their low-fat diet and because of the extremely quiet environments they dwell in.
8. The whip crack
SOURCE: The border mail
The sound that is made when someone cracks a whip is because the tip of the whip travels so fast that it breaks the speed of sound barrier and creates a sonic boom. Sound of it is enough to scare anyone, imagine someone being a victim there!
9. The shadow zones
Shadow zones are regions where one cannot here any sound. This is because the sound changes direction and bends upwards based on temperature changes. Sounds travel above cold temperatures and this phenomenon is used to the advantage of the submarines when they want to make themselves invisible to the sonar.
10. Whales sing to each other
Just like bats, whales have a unique technique to communicate in frequencies inaudible to humans. They sing to each other in the ocean. The sound of their song travels as far as 800 kilometers of distance. They can hear very low frequencies ranging from 10 hertz to 800 hertz and hence are able to communicate in a way that no one can hear. They like being private!
