What is a tuning fork? Description of the reference height and ideal sound source
The musical world is built on harmony and pleasant sound. This means that all instruments and voices must have the same build. It was not easy to achieve this, I needed a certain standard on which tuners and musicians could rely. Through trial and error, the world still learned what a tuning fork is.
Setup does not tolerate delay!
John Schur, the pipe maestro at the court of the great Queen of England - Elizabeth, adhered to this position. He listened a lot and memorized, possessing absolute pitch. In 1711, the trumpeter invented a strange object - a metal plug, from which a subtle sound was heard from a blow.
Oddly enough, this sound was clear and pleasant enough. It was decided to tune the instruments in it, right down to the organs and choral ensembles in the temples. The pitch was assigned to the note for the first octave.
What does a real tuning fork look like?
Musical device looks very much like a fork for fruits in high society. By analogy with the cutlery, it has two absolutely equal teeth, connected exactly in the center by a diverging handle.
Hearing the question of what a tuning fork is, often English-speaking tuners say so - tuner-fork, which literally means "tuning fork."
An interesting fact is that the sound of the tuning fork itself is very quiet, so it needs a resonator. Most often in his role is a wooden box located under the device. In order for the vibrations to resonate and the sound to grow, this box in length is made equal to of the sound wave.
A bit of frequency theory
If, what is a tuning fork, is already known, it is interesting to know what kind of standard it symbolizes and how it is determined. Initially, the height was 420 Hz, but as it improved in manufacturing increased. In Vienna and other theaters of European capitals, vocalists were indignant - the setting was inaccurate. So, in 1885 in Austria the standard of musical tuning was defined, where the frequency of oscillation of the tuning fork for the note of the first octave was 435 Hz.
At the beginning of the 20th century, the ideal sound again changed, stopping at around 440 hertz. The main reason for this is the ensemble form. The instruments of the orchestra, from wind instruments to strings, are tuned to the most convenient frequency, from 440 to 442 Hz. Found that the difference in 2 hertz is not detectable by the human ear, but different instruments may require it to complete the sound. The increased standard gave the sound brightness and greater expressiveness.
The frequency of oscillation, as is known, depends on temperature. Therefore, tuning the tuning fork should occur at exactly the specified temperature, and further verification of the sound with the instrument - at the maximum approximate to it. What is the reason for this?
The French master of acoustic equipment Koenig found out that with a temperature increase of 1 degree Celsius, the number of vibrations decreases by 1 to every 10,000. Therefore, manufacturers try to adjust the tuning forks by 20 degrees, which is the standard room temperature.
Achieving the desired sound
When you strike the tuning fork, you can first hear higher tones, which almost instantly fade away and leave only the main one.To achieve maximum accuracy and volume, as already mentioned, a resonator is attached - a wooden box, and sometimes other cylindrical or spherical structures made of glass or metal.
In the resonators, standing waves are generated, which are caused by the vibrations of the air from the impact. Thus, the sound is amplified, but stops faster. The most optimal is a steel tuning fork, since it needs less resonance, and the sound is clear and without strong amplitude. With slight fluctuations in temperature, it is the steel “plug” that is considered to be the standard of pitch.
Application in physics and other sciences
Tuning forks have become widespread among acoustics researchers in general. They achieve the longest sound with an electromagnetic tuning fork, keeping the oscillations at the same level for an unlimited amount of time (more precisely, limited solely by the flow of current).
An electric current is passed through the magnet coil, based on a galvanic cell (current source). Since any charged object is a magnet, the "horns" of the fork are attracted to each other.The overlapping current causes them to return to their original positions. The handle in this case acts as a circuit breaker. The invention of the device is assigned to Mercadier.
In practice, the device is used in the method of Sheybler and Lissajous to determine the exact number of oscillations over a period of time. Also, the Helmholtz microscope adopted the principle. With its help, string vibrations are much more effective to study. Tuning forks with resonators help to form standing waves in various devices, as well as used in chronographs.
Secrets of quality settings
Immediately before performing on a keyboard instrument, in no case can the piano be rebuilt to the same 2 Hz for “brightness”, from 440 to 442. The system will instantly crawl, which will become noticeable not only for the absolute, but also for the ordinary listener.
Pianos of the late 19th and early 20th centuries may not be adapted to those adopted later than 440 Hz, therefore they are tuned to the Vienna standard - 435 Hz at the desired temperature of 15 degrees Celsius. Attempts to adjust the above can lead to stretching and breaking the strings, and it is no longer possible to replace them with such an instrument.
Modern modified instruments in the orchestra, as a rule, can obey a single standard. Therefore, it is not worth experimenting with height. Everything is checked by simple electronic keyboards - always at 440 Hz, without the slightest deviation. Convenient for verification building in large ensembles.
Despite the abundance of modern gadgets for tuning, like tuners, the simplest steel device remains the most reliable and beloved. Every tuner knows what a tuning fork is - a reference sound accepted worldwide and established by centuries of research.