What is a microphone
The term MICROPHONE first appeared in dictionaries at the end of the 17th century. The word meant “an instrument for increasing the loudness of sound.” Such an instrument was, for example, a “trumpet” inserted into the ear of a hard-of-hearing person. The first microphone was constructed in 1827 by Charles Wheatston. As is known, these were the first “acid” microphones, which were widely used in the 1870s, thanks to Gray and Bell, and were eventually used in telephony.
Acid microphone
In the 1870s, the precursors of modern microphones appeared, the so-called “acid microphones,” in which a “stylus” connected to the diaphragm moves in the diluted acid present there.
Contact microphone, so-called “carbon”
The carbon microphone, created by the Grunding brand, was developed by Thomas Edison. In these, acid was replaced by carbon granules, which changed their resistance under pressure. This pressure is exerted by a vibrating diaphragm on the granules. The processing range of this microphone is rather narrow, and voice distortions are significant. However, the construction of this type of microphone is simple. They are almost fault-free, have rather high efficiency, and above all, they are cheap.
Piezoelectric microphone
Electrically, there are also so-called piezoelectric microphones, which are simply capacitors. These microphones convert an acoustic signal into a voltage signal. These microphones are rather sensitive to moisture and temperature changes. They also exhibit high internal impedance, which is capacitive in nature, which, of course, makes it difficult to connect them with long cables.
Dynamic “magnetoelectric” microphone
Air vibrations produced by sound waves move a very thin, flexible diaphragm in this microphone. As a result, voltage is generated at the so-called coil terminals. An example of a magnetoelectric microphone is the monophonic “MDU VII,” produced in the 1960s and 70s by Tonsil, an electromagnetic company.
The Museum at the Castle in Ćmielów is fully interactive. This institution does not have a display case character, but rather focuses on education and a lively presentation of sound and its evolution. At this place, Our Editorial Office of “Dziennik Polonijny” had the opportunity to see an exhibition of various types of microphones.
