Waves are caused usually by a movement in any form of matter caused by energy flow or by any disturbance made to a certain material. Waves can move through space and time at the same time.
They can be present in water, electricity, light, air, pressure, etc. Electromagnetic waves are those that do not need a material to be created such as lights, microwaves, x rays, etc. Mechanical waves are those that need a material to be created such as sound waves. Longitudinal waves are those that movement of the medium is parallel to the direction of the wave. Can be made from a gas because they do not need to be propelled. An example can be sound waves in the air. Transverse waves are those that the movement of the medium is perpendicular to the direction of the wave.
The wave usually moves vertically and the medium usually moves horizontally. Can be made at the surface of a liquid or a solid like a wave of a pond. Wavelength: The distance between two consecutive crests or two consecutive troughs of a wave.
Crest: Maximum value going up of the waveAmplitude: Maximum value of length of a waveTrough: Maximum value going down of the wavePeriod: Time it takes the wave to make a full expansion of the waveFrequency: Amount of waves made per unit of timeHow does a piano create sound?Sound in general is made in mechanical and longitudinal waves. Even though pianists are constantly playing, some never analyze what happens inside the piano. Some, however, may wonder: how can this instrument produce waves? To understand how the sound of a piano is produced, the parts of the types and parts of the piano must be understood first.
Even though there have been many variations in the piano throughout history, some are more commonly used than others. The two main types of pianos: the vertical pianos and the grand pianos. The vertical pianos are usually put against the wall and have different, less advanced, functions of the pedals. On the contrary, the grand piano has a tail and is usually put in the center of the room. This piano has more advanced functions in its pedals and is mostly used for concerts. These two pianos have most of their parts in common except for the way their pedals work. The first part of the piano is keyboard that, as its name says, has all of the keys of the piano. There are a total of 7 musical notes which repeat themselves usually 7 times in octaves.
The second part of the piano is the lid which makes the sound be softer and more contained when it is closed or louder and more spread around when it is open. The third part of the piano is the hammers which has the purpose of hitting the sting and making it vibrate so that it can sound. Every 3 strings have a single hammer. The fourth part is the strings which have 2 types: the treble strings and the bass strings. The treble strings have a sound that sound is acute and are physically shorter and thinner.
The thinnest cords have to sound more so there are usually 2 sets of chords of them per note. The bass strings have a sound that is deep and they are physically long and thick. The fifth part of the piano is the dampers which helps the vibrations of the chords stop after the key is released by the pianist. This does not happen when the pianist is holding certain pedals. The sixth part is the soundboard which is located at the base of the piano.
Its goal it to make the sound be heard. When made with dense and high quality wood (different types of brown) the sound waves are amplified better. This is the interior of a piano.
The keyboard can be seen at the very front of the image. Next, it is possible to see the dampers and the hammers that hit the chords. Also, it is possible to see the two types of strings and the wooden structure at the bottom which is the soundboard. This holds the entire piano and makes it sound.
Furthermore, the seventh part of the piano are its three pedals located at the bottom of the piano: one on the right, one on the center, and one on the left; these pedals are played with the feet. The pedal on the right of a piano makes all of the dampers go up so that the chord still vibrates and the sound fades slowly. Next, the pedal on the middle works differently for the grand piano than it does for the vertical piano. On the vertical piano, this pedal makes the sound weaker, which is also known as a sordina. This is made by putting a cloth between the hammer and the chord which makes the hammer hit the chord softer and the sound is not as loud. On a grand piano, however, this pedal is not used as often but it keeps the sound of the chords that are being played at the moment even if the keys are released. Only the dampers of the keys played are released and when the musician removes their foot from the pedal the sound is over. The last pedal, the one on the left, works differently on both pianos too.
On the grand piano, the hammers are moved so they do not hit the three chords of a key but they only hit two of them. On the vertical pianos, the keys move forward instead of to the side which makes them closer to the chords and the sound is lighter.This are the three pedals of the piano.
The one on the right puts all the dampers up. The one on the middle either makes the sound lower of keeps the chords playing even after released. The pedal on the left moves the hammers to the side or makes the keyboard move to the front more to either hit 2 out of three chords or to make sound lighter. The piano has a soundboard that is made out of wood which helps amplify its sound so people can hear it. This soundboard is essential because no sound could be heard even by the pianist if it wasn’t for it. This board holds a frame made of molten iron that helps keep the cords in place and helps them with tension. As a matter of fact, a piano has 230 cords made of steel that can be tight and all work because of the molten frame. When a key is played, the hammer (one per key) plays the cord precisely.
When the hammer hits the chord, the chord vibrates and produces the sound. The soundboard is a closed part so the sound vibrates in there and therefore we can hear it. If there is no soundboard, the cord vibrates but there is no contact with air so the sound is minimal. That is why the sound is so weak and needs an amplifier (no energy is transferred to the surface that helps it make contact with the air). To make the vibrations, the chords cross a bridge that is made of steel. That bridge helps transmit the vibration of the chords to the soundboard that sounds and sends amplified waves to the air surrounding the piano. The little dent in the grand piano helps take the sound and transmits with a better volume and a tone that is more tuned.
Finally, the damper goes up and lets the chord vibrate freely to make the sound. When the key is released, the damper and the little hammer go to their places and that is why the sound stops.As already mentioned, the sound of a piano is air that is being displaced when a chord vibrates as it moves particles of air around it and forms the waves that get to our ears. Sound waves can be affected by the piano’s imperfection of the wood. If the soundboard has a higher quality, the more the sound waves travel with a higher speed and lighter though the wood. Also, if the wood that makes the soundboard is strong, the sound waves can be transferred in a way that is uniform per wave through the table.
When it gets to our ears, we listen to a stronger sound than the one made by the chord on the soundboard initially; hence, the stronger the pianist plays, the more energy and sound the chord has. If the pianist plays really soft, the energy is very little from the chord so the sound is really low. In conclusion, the piano needs all of its parts to make it sound as it does and for the waves to get to our ears. As once said by Maria Cristina Mena, “The piano keys are black and white but they sound like a million colors in your mind.”