The first hearing aid. History of the development of hearing aids. century - suitcase devices

Candidate of Technical Sciences D. MERKULOV. Based on materials from foreign press.

PASSIVE ACOUSTICS

Science and life // Illustrations

According to legend, the Egyptian king Ramses II (c. 1327-1251 BC) had hearing problems. While talking, he tried to sit in corners that would amplify the sound.

The founder of modern cosmonautics, K. E. Tsiolkovsky (1857-1935), used bells made according to his own sketches.

Portuguese King VI of Goa sits on an acoustic throne chair with lions on the arms (photo from London's Amplivox Wax Museum).

Sound transmission table for confidential “closed” negotiations for two persons. The “microphone” was an audio cane (right).

Samples of transceiver acoustic wiring for collective use (above). Bottom: A vase in the middle of a table, a means of communication, is experienced by museum visitors.

Dentaphones are flat collectors of sound vibrations that implement auditory bone conduction.

An example of using the resonating cavity of a headgear to improve hearing (the oval contours in the front are the entrance holes for sound).

a, b - passive headphones, differing in the shape of the sound collectors; c - the headphone bells are directed forward.

Siemens' "Phonophore" was the first hearing aid with a telephone speaker and a carbon microphone powered by direct current.

The famous inventor and innovator T. Edison suffered from hearing loss; the invention of sound recording helped him and millions of others listen to music.

The first single-tube hearing aid (1921). The hole on the side is a microphone; Dimensions: width - 10 cm, thickness - 18.4 cm, height - 18.3 cm.

The first portable tube hearing aid with a microphone (front) and headphone output; polished metal case with battery inside; Dimensions: height - 16 cm, width - 8 cm.

Modern digital behind-the-ear hearing aid.

Science and life // Illustrations

In a digital hearing aid for two ears, the specified volume level in each of them is maintained automatically thanks to the established wireless data exchange between sound receivers.

The equipment and power data of a modern home musical theater make it possible to take into account individual hearing characteristics and smooth out its deficiencies.

A specially equipped classroom at the faculty for the hearing impaired at the Kazan Institute of Continuing Education. (Photo from TV screen.)

Science and life // Illustrations

Listening, a person instinctively puts his hand to his ear. Placing your palms on your own ears can significantly enhance the perception of sound. Modern acoustic measurements show that in this case the hearing threshold increases by 3-10 times (5-10 dB) (for the conversion of the ratios of sound volume levels into decibels, see “Science and Life” No.). Even better amplifier-resonators were the shells of sea mollusks, turtle shells, and the horns of domestic animals. All these devices are natural hearing aids. The first images and description of a passive hearing aid of the horn (cone) type are given in the book “The Magic of Nature” published in 1588 by the Italian physicist, physiologist and philosopher J. Porta (Giovanni Battista della Porta, 1535-1615). The author described and recommended for use for the hearing impaired wooden imitation ears of well-hearing domestic and wild animals.

Discussions about the benefits of applying pipes to the ears of the hearing impaired are also contained in the works (1625) of the Englishman F. Bacon (1561-1626). At the end of the 17th century and in the 18th century various kinds tubular conical “collectors of air disturbances manifesting themselves near the head” were very common. Materials for auditory tubes Wood, bone, tin, and copper were used. Thanks to their amazing ability to amplify and capture sound, conical bells brought distant objects closer “by ear”; they began to be used even in the army and navy, long before the invention of binoculars for the eyes (1825).

The famous composer L. Beethoven (1770-1827), having weakened hearing towards the end of his life, used parabolic resonators, cylinders, tubes, public speaking hid conical ear tips in his hair. Largely thanks to mechanical hearing amplifiers, being already almost deaf, he wrote his last, Ninth Symphony. The famous scientist K. E. Tsiolkovsky also had to use bells. The disease does not spare celebrities.

The original introduction of acoustics achievements into furniture items was presented to the civilized world at the beginning of the 18th century. The famous French theologian, interested in the acoustics of churches and cathedrals, J. Duguet (Jacgues-Joseph Duguet, 1649-1733) is credited with the invention in 1706 of a special seat - an elevation in the altar for one of the hard-of-hearing high-ranking ministers of the episcopate. Founded in 1800 in London, the company "F.C. Rein&Son" began to produce specialized upholstered furniture on orders for the hearing impaired. It is known that from 1819 until his death in 1828, the original sound-transmitting throne chair was used by the King of Portugal, John VI (also called King of Goa VI), who did not want to put up with deafness. The king's associates and visitors had to kneel down and speak into the open mouths of the sculpted lions located at the front ends of the armrests. Important messages and reports were relayed “upward” by a resonator hidden under the seat, ending in a flexible tubular sound duct.

Inventive thought did not stand still. The British "aurist" (phoniatrician) and otorhinolaryngologist D. Curtis (Jon Harrison Curtis, 1778-1860), the Irish physicist W. McKeown (Willian A. McKeown, 1844-1904) proposed the design of the chairman's chair (each his own). In both designs, the sound intensity increased to 30 dB.

The company "F.C. Rein&Son" has launched other products that are distinguished by their originality. For example, an acoustic table for confidential negotiations, designed for two people with both limited and normal hearing. The table top had four round holes at the end, of which two large ones were designed for connecting tapering flexible air ducts with tips for ears. In the other two, smaller in diameter, cylindrical branches of canes were inserted, hollow in the upper part, which acted as speech receivers. In modern terms, a single-table means of communication was an acoustic quadripole: a resonator vase was fixed on top of the table cover, and hollow wiring was hidden underneath it. It was assumed that a specially designed device would allow conversations to be conducted at a lower volume without attracting the attention of others. Acoustic tables were produced with three and four seats spaced in a circle. In another transceiver acoustic device of that time, a decorative vase 30 cm high installed on a table masked metal cone horns that caught sound vibrations coming from people talking at the table. The same horns simultaneously served as emitters of the directed action of spoken phrases and expressions for the interlocutors. Any one person was given the opportunity to listen to everyone present through a flexible sound conduit stretched under the table.

For patients with hearing impairment in the middle ear, but who have retained the connection between the organ of Corti (cochlea) and the outside world thanks to bone conduction solid and folding “dentaphones” (dentaphon) were produced, clasped by the teeth at their ends when listening colloquial speech or music. Among the fair sex, “dentaphones” were replaced by elegant membrane fans. For both men and women, bell hats with masked entrance (for sound) holes in the front or at the top were recommended for street walks; headgear resonators excited the cochlea inner ear directly through the oval of the skull or air vents into the external auditory canals of the ears. In the army units of individual countries, metal helmets of a similar design were used for certain types of operations (for example, night reconnaissance). At the end of the 19th and beginning of the 20th centuries, passive headphones were common, which were simple sound detectors attached to the ears. In the absence of active loud sound reinforcement at that time, they were also rented to spectators in the back rows of drama and musical theaters. Such headphones are still in use today. They are also good because they do not require any energy supply.

ELECTRICAL BOOST

In the years preceding the filing of a patent application for the telephone, its inventor, Scottish-American A. Bell (Alexander Bell, 1847-1922), taught at a youth school for the deaf. He soon married one of the school students. In the year the new means of communication was presented to the world, the inventor was only 29 years old. Bell's biographers believe that the ongoing work on researching the information capabilities of wired networks was also stimulated on a personal level: he wanted to quickly help his wife, as well as his hard-of-hearing mother and sister.

In 1878, the American physicist D. Hughes (1831-1900) developed a carbon microphone with improved electrical conductivity, which is still used in recording and film studios, radio and television. In the same 1878 in Germany, W. Siemens (Werner von Siemens, 1816-1892), based on Bell's telephone and Hughes' microphone, created a sound amplification device for the hearing impaired. It was called a "phonophore". In 1890, A. Bell founded the Association for Hard of Hearing and Deaf Children in the USA, which from then until now has supported the scientific development and production of electronic devices in its chosen field.

Invention American engineer L. Forest (Lee de Forest, 1873-1961) of a three-electrode radio tube in 1906 revolutionized sound amplification (see "Science and Life" No. 6, 2004). It is clear that engineers immediately began constructing low-frequency tube audio amplifiers for hard-of-hearing citizens. However, serial portable loud-sounding hearing aids appeared only a decade and a half later. The first company to produce a prototype in 1921 was Western Electric (USA). The microphone was used carbon. The amplifier consisted of one tube. One earphone with headband was connected to the output circuit. The device was large and heavy, but it fit in a briefcase. For the three-lamp version released later, a suitcase was required, and women needed a porter to carry it even over short distances. Both developments, like all other later ones, had to be connected to the mains; the filaments of the lamps in them were powered by a separate battery. The same "Western Electric" in 1932 managed to create the first portable hearing aid with an output to two headphones held together by a headband and placing a metal rectangular assistant on the belt or chest (using a cord). The power battery was fastened with a belt under the arm, and for women, sometimes slightly below the waist, on the thigh - under a wide skirt.

HEARING TEST

In the early 1930s, in the American "Bell Laboratories" under the leadership and with the direct participation of the already famous scientist - physicist and acoustician H. Fletcher (Harvey Fletcher, 1884-1981) measurements were carried out frequency characteristics ear at low and high volume levels (see "Science and Life" No.; No.) The upper and lower thresholds of audibility were determined (see "Science and Life" No.). At the same time, it is stated that the dynamic range of the hearing organ is naturally designed for changes in the volume of human speech and is therefore 60 dB. However, when strong noises it shifts to the region of the upper threshold of audibility, and in silence it is near the lower limit. The travel time constant (response time) is quite small, which allows a person to listen to popular and classical music with a characteristic dynamic range of 100 dB. The work performed allowed us to formulate technical requirements to relatively inexpensive household equipment that has begun to be produced en masse, and to hearing aids that have also become significantly cheaper.

In these years, audiometry essentially became established as a scientific and practical discipline. Audiometers came to clinics, where they began to test the hearing not only of hard-of-hearing patients, but also of pilots, railway workers, sailors, drivers, police officers, and others entering work. Nowadays, such tests are also recommended for developers of the now very popular home speaker systems, specialists and managers for their operation and sales, as well as radio amateurs who are passionate about high-quality Hi-Fi sound.

The establishment of mass production of an increased range of receivers and amplifiers that expanded the capabilities of the hearing organ, research undertaken into the characteristics of the ear in the 1920-1930s led to the creation of areas of electrical radio measuring equipment focused on interaction with human ears. Over the years, various types of standard electrical bridges for measuring inductance, capacitance, resistance, radio wave meters, and frequency standards were produced and used until the end of the 1970s, in which high-precision indication of zero beats was carried out “by ear” using headphones. For military purposes, until the advent of radar, sound direction finders for approaching aircraft were produced. These, for example, successfully participated in the defense of Moscow in the fall of 1941 (see “Science and Life” No.).

DIGITAL INVASION

In December 1947, a public presentation of the invented transistor took place in the USA at Bell Laboratories. Physical experiments, laboratory experiments, and metrological measurements associated with the epoch-making breakthrough were carried out in the research department, headed by X. Fletcher. Already at the beginning of 1952, the American company "Raytheon" began producing miniature semiconductor triodes specifically for hearing aids. However, the device, developed in the same year, still contained three radio tubes with hair leads and only one transistor. After just a few months, an “Acoustion” appeared with one transistor with a high gain, and a little later a “louder” device with a low-frequency amplifier with three transistors appeared. The new small-sized hearing aids did not yet have a compartment for batteries; they were still attached to the wearer's belt. Despite the apparent obviousness and simplicity of the technical solution, the constructive integration of the device’s wiring diagram with the power source occurred several years later. At the same time, hearing-improving devices have again noticeably dropped in price at retail, mainly due to cheaper batteries (compared to batteries for lamps), which also extended their service life thanks to sharp decrease current consumption in the load. Mass production of microcircuits, which began approximately 10 years after the release of the transistor, contributed to the arrival of a new generation of hearing aids, further reducing their size and energy consumption while simultaneously increasing efficiency, expanding functionality, and improving hygiene.

IN last years circuits became digital with microprocessor control. In practice, it means, for example, automatically adjusting the polar pattern of a microphone, increasing or decreasing its sensitivity, noise suppression and selection, that is, selection, selection of speech signals in a wide variety of situations - on the street, a noisy meeting, in the theater.

Any headphones must be connected to the output of an amplifier. Hearing aid from regular headphones differs in that the amplifier is located inside and near his ear. With the indicated advantages, it can be rationally used by everyone who has good hearing, including, perhaps, during negotiations in the office, at lectures at the institute, while on guard duty, walks in nature, etc.

When two devices communicate wirelessly to provide the ears with balanced data from the surrounding sound field, the microprocessor automatically increases or decreases the gain of their amplifiers or regulates the flow of signals in any one of them. Normally hearing people can also use a combination of two hearing aids, for example, when talking on a mobile phone, replacing the recommended lower-quality wired connection with one earphone.

In recent years specialized organizations in Europe and America, they launched the production of miniature and light-weight in-ear devices placed in the outer ear canal ear. The devices are reliable and practically invisible to others. However, for them the issues of compatibility with the sufficiency of the width of the amplitude-frequency response have not yet been fully resolved.

SAFETY

Quite often in popular magazines, managers medical institutions and their qualified specialists tell how well they treat diseases. This, of course, makes you happy, but it’s better to try not to rush to get to them, and do more preventive measures - stick to a diet, exercise. In general, take care of your hearing, dear readers.

It should be noted that hearing, from the standpoint of transmitting data to the brain, is several times less informative compared to vision. However, even a slight deterioration in hearing by 20-30 dB in schoolchildren and students can affect academic performance and immunity to the sense of danger in a certain environment.

Research conducted in 2002 in the USA showed that long-term exposure to hearing loss loud music(4-5 hours) through the headphones of an MP3 player or at a disco causes thickening and swelling in nerve fibers, connecting the cochlea of ​​the inner ear with the brain. It takes about two days for them to heal (see “Science and Life” No. 11, 2002). With daily “rape” of the ears, conditions for cell regeneration are not created, hearing loss occurs, and more informative right ear suffers first.

If a gun is fired over the ear of a person sleeping in silence, he will become deaf, since during sleep the hearing organ is most sensitive to noise. In conditions, however, less exotic, quite often the ear is also not prepared for surprises - when children shoot from a “scarecrow”, adults on a hunt, all together using pyrotechnics at a festival, etc. By the way, pets (dogs, cats) instinctively Hearing the gunfire, they run away. In the laboratories of the research institute, production workshops Noises with a level of 80 dB or more are considered hazardous to hearing.

In offices and at home, excessive noise is created by fans of obsolete PCs, large memory devices, and measuring instruments. Their level rarely exceeds 60 dB, but daily exposure to them for 8 hours or more traumatizes the psyche and impairs the audibility of high frequencies (more than 5-6 kHz).

Young children and the younger generation are less resistant to noise than adults. Unfortunately, they may experience irreversible phenomena. Walking in the forest, reading literature and sleeping in silence, listening to quiet classical and popular music, “loaded”, help restore hearing. high frequencies(see "Science and Life" No. 12, 2006), on high-quality radio equipment. For lovers of modern "club" music there is good news- vibration of the peritoneum and abdominal diaphragm from various types of electronic subwoofers has virtually no harmful effect on health. From which we can conclude that loud mid-frequencies, to which the ear is most sensitive, are dangerous for hearing.

POST FACTUM

Engineering thought has stepped far forward. Modern technology now allows many people who were unable to enjoy simple human joys to feel equal to everyone else.

One of the most beautiful young women, for the first time in the world, being deaf almost from birth, won the prestigious beauty contest "Miss America 95". Heather Whitestone knows for sure that the impossible is possible, and she proved it by example. She was one and a half years old when she lost her hearing after suffering from the flu. Overcoming the illness, she studied at a regular school, studied ballet, and completed a three-year rehabilitation course at a special institute for the deaf.

A modern miniature hearing aid helped her take part in the competition.

Whitestone considers his victory an inspiring example for thousands of disabled people. At the Best Hearing Institute, founded in 1973 in Alexandria, Virginia, she gives lectures and mobilizes deaf people to overcome barriers that prevent them from living a full life. At the same time, it is worth mentioning that those suffering from the disease also worked at this institute and are actively collaborating with it - one of the pioneers of the Internet (see "Science and Life" No. 11, 2004) Dr. V. Cerf (Vinton Cerf), former presidents USA J. Carter, R. Reagan and their wives, many famous people from financial circles, industry, culture, and sports.

In Russia, 13 million people live in silence and, overcoming inevitable difficulties, live full life thanks to the All-Russian Society of the Deaf (VOG). This society has existed in the country since 1926. It introduces people with hearing impairments to work, increases the level of general educational and professional knowledge, and organizes cultural recreation and leisure. The state also cares.

Recently, the country’s second department for the hearing impaired was opened at the Kazan Institute of Continuing Education. (The first, as you know, exists at Moscow State Technical University named after N. E. Bauman.) In addition to subjects common to everyone, students study sign language, learn to read lips, and speak a lot. The learning process uses an interactive whiteboard, the Internet, and sign language. There are mirrors hanging on the walls throughout the classroom: here, vision is the only way for students to observe what is happening around them.

Next year they will all study together with healthy children and at the end of their studies they will become highly qualified specialists - accountants and will work in ordinary Russian institutions.

The first official mention of hearing aids appeared in a book published in 1588 called Magia Naturalis. In it, the Italian doctor, scientist and cryptographer Giovanni Battista Porta describes devices made of wood and repeating the shape of the ears of animals, naturally endowed with acute hearing.

Over several centuries, the device has evolved into a tiny device that is practically invisible to the naked eye and does not even remotely resemble the hearing organs of representatives of the animal kingdom. The speed of development of technology can hardly be called rapid - until the discovery of electricity, people with limited hearing abilities had to use all kinds of tubes, the size of which often reached half a meter.

XIII-XVIII century

As early as the 13th century, people with hearing loss were using hollowed-out horns from cows and rams as primitive hearing aids. Their design did not change until the 18th century, when more modern pipes were invented. The funnel-shaped ear tubes were man's first attempt to invent a device for treating hearing loss. Most of these early devices were made from animal horns or shells and were quite large - 40-60 cm in length and approximately 15 cm at the widest part. They did not amplify the sound, but “collected” it and directed it through a narrow tube into the ear.

In the 18th century, the effect of bone conduction was also discovered. During this process sound vibrations transmitted through the skull to the brain. Small fan devices were placed behind the ears, collected sound waves and directed them through the bone behind the ear.

Until humanity discovered the possibilities of electricity and the telephone in the 19th century, ear tubes remained the only possibility Help people with hearing loss live full lives.

19th century

Later, metals such as copper and brass began to be used to make pipes. The craftsmen have learned to design auditory tubes in various styles, depending on the client’s preferences and the degree of hearing loss. Ludwig van Beethoven is considered the most famous fan of auditory trumpets. The composer suffered from a severe form of tinnitus - ringing in his ears prevented him from perceiving and appreciating music, and around 1796 he began to lose his hearing. The Beethoven House Museum in Bonn houses a large collection of ear tubes that helped him hear music and speech.

Ludwig van Beethoven's Ear Trumpet Collection

In the 19th century, the disguise of hearing aids was given great importance. Although the devices were still quite large, craftsmen managed to turn them into attractive decorative accessories and incorporated them into collars, hats and hairstyles. Sometimes they were covered with enamel in flesh color or the color of the client's hair. Some men have tried to completely hide the devices in their beards.

Members of some royal families owned devices built directly into their thrones. Special tubes collecting voices and sounds were passed through the armrests. The sound was directed into echo chambers and amplified, then exited from an opening near the monarch's head.

One of these cleverly disguised hearing aids was made for King John VI of Portugal: the armrests of the throne were made in the shape of lions with open mouths. Each of them housed a resonator that picked up sound and sent it to the earphone.

Throne of John VI

Around the same period, another type of hearing aid was invented: the speaking tube. Its wider end was held towards the speaker's mouth, and the other was placed directly to the listener's ear. Not very convenient, but more effective.

XX century

In the early 1900s, with the advent of electricity and the telephone, a new generation of hearing aids with an electronic sound amplifier, a carbon microphone, and a battery began to develop. Such devices were bulky boxes that had to be worn around the neck. Long wires protruded from the box and were connected to a heavy battery that only lasted a few hours. To extend the life of such devices, some people carried even heavier and larger batteries. In addition, the more severe the hearing problems, the larger the microphone had to be used.

One of the first electric carbon hearing aids

Such devices, despite all the technological improvements, did not show much improvement. Most of them only amplified speech to 15 dB, which is not very much when speech volume typically averages 60 dB. And even amplified speech did not sound very good: the sound was noisy, creaky, and a person could only distinguish a very narrow range of acoustic signals.

The advent of the vacuum tube greatly accelerated the progress of hearing aids. They were able to transmit sounds that were much louder and clearer than carbon electric hearing aids. Some could amplify the sound to 70 dB or higher. However, this improvement has affected the size of the device. Early lamp-powered apparatuses were about the same size as early coal-fired ones. The first tube hearing aid was invented in 1920 and was about the size of a brick.

Lamp apparatus

Like carbon electric hearing aids, tube hearing aids have become smaller over time. Later designs could be tied around the chest or arm. Vacuum tubes and batteries prevented further reduction of the apparatus.

The invention of the transistor in the 50s completely changed all types of technology, and especially influenced the technology of hearing aids. They worked in much the same way as vacuum tubes, but were much smaller. Transistors were used in hearing aids two years before they first appeared in transistor radios.

Transistor hearing aid

The first deliveries of transistor hearing aids occurred in 1953. The devices quickly gained popularity: in the year of release, about 50% of sales were transistorized, and in 1954 - 97%.

The earliest transistor devices were about the same size as later tube devices. By 1956 they were small enough to fit behind the ear. This design solution is still found today.

Another popular device at that time was hearing glasses developed by Otarion Electronics. By 1959, half of all transistorized devices were made in the form of glasses, and even people with excellent vision preferred to wear them.

Hearing glasses

In the 1960s, the first devices were developed that were placed directly in the auricle. Back then they were not as reliable as their larger contemporaries, but over time the technology has been refined.

The advent of silicon transistors made it possible to create hearing aids close to what we know today. The first such device was developed by Zenith Radio in the 60s. In these versions, the microphone came out of the ear and was connected by a small wire to an amplifier that was attached to the ear. This technology remained virtually unchanged until the 1980s, when digital signal processing chips came into use for hearing aids.

All devices of that time, transistor or tube, worked on the same principle: they caught sound waves, amplified them and sent them to the ear. In other words, they simply provide the ear with loud sound. All their work relies on properly functioning inner ear, which converts sound waves into nerve signals. The devices could not help those whose ears did not function properly.

Cochlear implantation came to the aid of these people. Cochlear implants sent electrical signals directly to the cochlea, the part of the ear that senses and recognizes sounds. They were intended for patients with profound hearing loss who cannot use conventional hearing aids.

The microprocessor, invented by Edward Hoff, allowed the miniaturization of logical functions in electronic equipment. Hearing aids using microprocessors began to appear in the late 1980s. The earliest wearable digital hearing aid, Audiotone, appeared in 1983. It had behind-the-ear parts that included A/D, D/A and DSP switches. Digital devices created during this period could effectively reduce noise environment while improving speech quality. All hearing technologies on the market today are primarily digital.

Present tense

By 2000, hearing aids were programmable, allowing the addition of a range of custom settings. By 2005, digital devices accounted for approximately 80% of the hearing aid market. Digital technology uses the same circuit as in mobile phones and computers.

Modern hearing aids can be adjusted by audiologists depending on the individual characteristics patient. They can adapt them to different listening environments and connect additional devices - computers, TVs and phones. Antennas, Bluetooth and FM connections ensure compatibility with and access to other electronic devices in in public places. In 2011, renowned technology device manufacturer Siemens released Aquaris, one of the first waterproof, dustproof, shockproof hearing aids.

Today, hearing aids continue to evolve along with the world high technology. Smart devices are appearing on the market that adapt to various situations automatically, without user intervention. In 2015, ReSound developed the first hearing aid for a smartphone that does not require intermediate sensors. It is designed specifically for iPhone to help you hear the device better.

Replacement therapy, as mentioned above, includes hearing aids and training in face reading.
The term “” is somewhat inaccurate, since prosthetics usually means the replacement of an organ, and devices that can replace a person’s lost hearing have not yet been created.

It's clear how hard it is transferred patients with hearing loss or impairment and how this affects their mental state and ability to work. Although this issue has been studied for a long time, the problem of replacing lost hearing has not yet been completely resolved.

Since ancient times it has been observed that faces with reduced hearing, place a bent hand to your ear during a conversation. This increases the size of the pinna and thereby increases the perception of spoken language (Lucae et al.). On this basis, various ear tubes have been proposed. Thus, Archigenes was the first to propose the use of special tubes that collect sound. Further, in the 17th century. Kirchner proposed a device consisting of a funnel and a curved tube. Then hearing aids appeared in the form of a horn (Nuck), a hunting horn (Politzer). Syk recommended the Politzer straw as less conspicuous.

Meaning of application auditory tubes is that s. with their help, sounds entering the ear are significantly amplified, but they cannot improve the perception of sounds. And currently, hearing tubes are being found limited use, mainly with senile hearing loss. The latest model of the auditory tube was proposed by I. A. Lopotko and L. D. Kudryavtsev.

Due to the development technology To amplify the transmitted sounds, it was proposed to use electric and radio tube devices. The first electric hearing aid was manufactured in 1875 by Bell. It should be noted that for almost 50 years the first hearing aid was not modernized. It was not until 1922 that Leiter, by modifying the air telephone, significantly reduced the cosmetic disadvantages of the first electric hearing aid. Then, in 1924, a microtelephone amplifier was introduced into the device circuit, which improved the amplifying properties of the hearing aid. Further improvements concerned improving the quality of the microphone, amplification devices and power supplies. The introduction of a volume control (potentiometer) into the circuit of a hearing aid allows a person with reduced hearing to adjust the sound intensity according to the degree of hearing loss.

Creation of a piezoelectric microphone with tube amplification led to an improvement in the quality of the hearing aid (A. Ya. Chebotarev). In addition, the hearing aids were equipped with a tone control, which made it possible to change their frequency response

Hearing aids is an artificial amplification of speech to use surviving remnants. It is important that the hearing aid provides sufficient speech intelligibility, and this can only be achieved if excessive volume does not reduce speech intelligibility. Improvements in the acoustic and performance properties of hearing aids have contributed to their widespread use, and recently hearing prostheses have begun to compete with surgical interventions aimed at improving hearing.

However, when hearing aid recommendations You can sometimes encounter prejudice from patients. What matters here is:
1) the patient’s reluctance to show that he has difficulty hearing,
2) fear that after using the device for a long time it will be impossible to do without it and
3) fear that the device may be harmful to the remaining hearing. Regarding the first objection, advances in radio electronics have contributed to the creation of prosthetics that can be camouflaged. This includes hearing glasses and hairpins for women (they will be described below).
The second consideration is not without some grounds, but it should be remembered that a hearing aid is prescribed mainly to patients with persistent forms of hearing loss for constant wear.

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This is a complex microelectronic device that allows you to recognize the sounds of the surrounding world.

Today, hearing aids will no longer surprise anyone; it allows people to lead a normal life, despite hearing loss and deafness, and children to develop normally and keep up with their peers.

17th-18th century - ear horn

Several centuries ago, people could not even dream of prosthetics. There was no way to cure hearing loss. However, the doctors did not give up and tried to fight. The first prototype of the hearing aid was shaped more like a baby's horn: a large tube tapered to one end, which was inserted into the ear - this made it possible to collect large quantity surrounding sounds.

19th century - suitcase devices

The next stage in the development of hearing aids is associated with the discoveries of Alexander Graham Bell and Thomas Edison. Bell invented the telephone, and Graham, using a carbon microphone and a battery, was able to amplify the sound in the telephone.

But Thomas Edison was able to turn the ear horn into an electronic device. He created a carbon transmitter - a device that turned sounds into electrical signals, and then translated them back into sound.

Mass production of the first devices began at the end of the 19th century. Several companies in Germany, the USA and other countries began developing devices to improve hearing. Each of them created their own design and applied their own approach. But the first was the American corporation Dictograph Company.

Due to the heavy carbon battery, the first hearing aids were so bulky that they were carried by hand. But this did not stop the patients; the exorbitant price did not stop them either.

Mid-20th century - transistor hearing aids

Equipment manufacturers quickly responded to the advent of hearing aids, and in 1920 the first hearing aid with vacuum tubes appeared. The sound quality and volume have improved, but the equipment remains heavy. The main reason larger sizes were the same coal batteries.

The problem was solved as soon as transistors were invented. This happened in 1952. Initially, the hearing aid was placed in the temple of glasses, but this was not always convenient, so over time, devices were developed that were attached behind the ear. This is exactly how the hearing aid came to us.

21st century - digital and invisible

Modern hearing aids are miniature, with good selection they are practically invisible to others. Complex microcircuits ensure high quality sound transmission, and digital technologies make it possible to make devices “smart”. The program not only perfectly conveys sounds, but also highlights human speech, enhancing its sound.

Qualified selection of a hearing aid is the most important point in hearing care. Technology has reached high levels, so even “unpromising” patients are not left without help. But note that this concerns professional selection, and not a “finger in the sky” selection. Devices that are purchased spontaneously will not only affect your personal funds, but also your health.

A variety of hearing aids on the market meet many parameters, and if you are buying a hearing aid for the first time, then seek help from a specialist. It is best to entrust the selection to a hearing prosthetist. The medical device market is now diverse, so you won’t be able to understand all the intricacies and nuances on your own, but a qualified specialist will be able to do everything for you and give detailed advice.

First, your hearing care professional will review your audiogram, report, and referral from your audiologist. Some devices have contraindications. For example, intra-ear (intra-canal) earbuds cannot be used for inflammation of the middle or outer ear. People with musculoskeletal disorders are also contraindicated to use intracanal and in-ear hearing aids, and epileptics are not recommended to use the devices at all.

An audiogram is a characteristic of the patient, “instructions for action” for the hearing professional. An audiogram can help you understand the degree of hearing loss. This is also taken into account when choosing a device. For example, when heavy losses It is more reliable and expedient to use a convenient behind-the-ear digital hearing aid. The power should be appropriate for the level of hearing loss.

A competent specialist must learn about the peculiarities of your lifestyle. For example, you constantly travel and actively communicate with people, play sports, here the device can only be an obstacle, but the task of the SA is to improve and maintain your lifestyle, to be invisible and in no case be a hindrance. In such cases, in-ear devices would be a winning option.

The CA is required to ensure maximum comfort and speech intelligibility. To date. The most popular are digital CAs, which are configured using computer technology. All settings are made individually.

Make sure your hearing aid batteries are replaced on time. It is best if you check the amount of charge remaining in the batteries before going to bed.

Modern devices differ from each other in prices and capabilities. Finding the right one is the task of the hearing care professional, but not yours. Don't risk your health!

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