We live in an ocean of sounds. The world around us is filled and even sometimes full of sounds. Knock like a door slamming, ringing the water jet, continuous rumble of cars outside the window, the noise of the tram, voices speaking people, the roar of the vacuum cleaner, the hum of the electric shaver. It is a city. It's his voice. Or the chirring of crickets, discordant chorus of birds, the rustle of leaves, the sound of distant trains, chugging boat on the river, coming from somewhere hooters... it All sounds. We hear them. Thanks to them we fuller, brighter perceived surroundings.
What is the sound? From the point of view of physics this wave. Wave that occurs as a result of fluctuations of some elastic body. Its oscillation is transferred to the air, and the air wave, in turn, affects our eardrum, and we hear the sound.
But the sounds are very different. Those that are heard around us and create a constant background of our life - sounds that are not organized in any coherent system, not related to each other. And sounds special qualities: a cleaner, more mellow, with a certain height, having a semantic expressiveness - the sound of music. Publish their musical instruments or voice is also a kind of musical instrument, with the most perfect. The sound wave in them arises from the vibration of the string, metal, stretched skin, or, finally, the column of air contained within a metal or wooden tube.
Sounds differ in height; in duration, i.e. the length, duration of the sound; voice - specific color, which depends on the material, size and shape of the instrument, the method of sound production; and, finally, the dynamics, i.e. the power of the sound. All these properties, you can read the stories of "pitch", "Duration", "Voice" and "Dynamic tints.
Sounds immeasurably much, but the music can be applied relatively limited. Experiencing these restrictions because of the properties of the sounds themselves and because of the nature of human perception.
For example, too high or too low sounds the human ear does not perceive. This so-called ultrasound and infrasound. They are used by man. Ultrasound treated; infrasound effect on the psyche: causes fear. In other words, we perceive them, but not in sound quality. Or limitation of the duration: the short may be the sound that people are still able to publish or to remove from the tool, but its length cannot be excessive. There are boundaries and dynamics: too strong sound ceases to be an aesthetic category. It can even cause real physical pain, not to mention the negative impact on the psyche. By the way, so bad that in recent years the hobby too loud sounds. You should not enable the full capacity of the tape player or radio. At the very least, what this will lead to a hearing loss, partial deafness.
What is bad headphones
Love to listen to music on headphones? But this is very, very harmful and can lead to partial or even complete loss of hearing! Especially if you like to enjoy music at high volume using besides ear plugs or liners that are inserted inside the ear. The fact that these headphones fit very close to the inner ear. This leads to damage to the nerve endings of the eardrum, which is responsible for transmitting impulses to the brain. The optimal volume of the sound in the headphones, if you listen you can hear your own voice and speech of the people around you, and they, in turn, do not disassemble the words of the songs that sound in your headphones. Experts advise to adhere to the rule "60/60": listen to music in headphones no more than 60 minutes in a row and on the volume not more than 60%.
And even prolonged listening music in headphones can cause headaches, increased blood pressure and intravenous voltage.
In the XX century there were special kinds of music - the so-called concrete and electronic music. In particular the music used non-musical sounds such as rattles, noises and rattles screeching saws and other, which the composer organizes in its sole discretion. In electronic music sounds, arising out of or converted with the help of different devices. Both types of music are often used in movies. Especially love the composers to use electronic sound in sci-Fi movies.