The World of Sounds

From day to day, being engaged in our activities, having a rest, or even just moving around in the city, we hear hundreds of sounds. All of them differ with their pitch of a tone, their duration and volume.

So, what’s the sound, at long last? Let’s remind the school curriculum of the physics and refresh our memory on these notions.

The sound is a wave, which is distributed to the surroundings, which makes mechanical vibrations. Some physical systems are unable to conduct the sound – for example, the vacuum, as far as there is nothing to cause vibrations in the vacuum. Some materials conduct sounds better than others – because of the greater density of molecules. Thus, the metal, for example, conduct the sound better than the air.

I’m sure, that ones of the most melodious sounds in the world are the sounds of music, but how the music could exist without musical instruments?

Musical instruments

Musical instruments can be divided to 3 types:

1. 1. Wind instruments: the sound is made by the air, which is passed through a little hole at great speed so, that straight in front of the hole, the zone of the high pressure arises. This zone makes the coming-out molecules move even quicker at that and creates, in so doing, air vibrations, which are enough to be caught by a human ear on the proper frequency.

It’s possible to put down to them organs of diverse modifications as well as accordions.

There is one peculiarity in this type: the sound stops as soon as the air injection does.

2. Stringed and membrane instruments: diverse guitars, violins, harps, drums, tambourines, and pianos.

Here the sound is elicited by disturbance of the oscillating systems: strings or membranes.

According to the structure, it’s possible to reckon to suchlike instruments: musical triangles, tuning forks, non-membrane percussive instruments (e.g., hats). The peculiarity of these systems is that they keep on uttering the sound even after the disturbance stops. (in the pianos, for example). Different dampers are used for this purpose.

3. The last and the smallest group of instruments is where the sound is made by physical reciprocal action of two matters: different types of percussions, maracas. Here the sound also stops as soon as the interaction of matters does

So, we sorted out how the sound is made in the musical instruments. Now, let’s try to sort out how we hear them.

Human ear

Every person has tympanic membrane in his ears. It represents the pure and simple membrane, which oscillates beingdisturbed with any sound. The membrane vibrations are conducted to the malleus, it beats to the anvil in its turn. From there, the vibration goes to the ear bone, which conducts the sound to the inner ear – and further – to the brain. By the way, the malleus, the anvil and the ear bone are the smallest bones in the human body, their size makes no larger than a rice grain.

With the time the hearing apparatus wears out, and a person becomes unable to hear the top range of frequency. Thus, people under 18 usually hear the sound frequncy to 20 000 Hz, under 30 – to 16000, under 40 – to 15 000, under 50 – 12000, and under 60 – 10000, for example.

Often we don’t even think about the evident mechanisms in the functioning of our organisms, such as: walking, speech, and hearing. We just walk, speak and listen. But once thought, the essence of our abilities is so amazing! It turns out that the hearing system never takes a rest, it functions round-the-clock, and is able to retain its functionality during tens of years! It proves once again that, probably, the human will still spend a very long time, poring over drawings to be able to create artificial systems, which can compete with their natural analogues. Finally, the human is not the Lord of Nature, but just the most intellectual child of it.