Hearing protectors

When hearing protection all kinds of protective devices and protective equipment are called to protect the ears from loud noises and acoustic trauma prevented.

Areas of application

In an environment with a high noise level, as when working near loud machinery (airport, road construction, industrial machinery, etc. ), use of hearing protection in the workplace in February 2006 from 85 dB ( A) is prescribed. Furthermore, it is also required that the part of the employer from 80 dB ( A) suitable ear protection is available. Even with music events of all kinds (concerts, nightclubs, festivals, parades, etc.) this sound pressure level is often exceeded by far. For all types of events, the EU Directive applies to workers who DIN 15905-5 for the permissible sound levels, which the public may be exposed and the Council to take the hearing protection into their own hands.

Other areas of use: Making music with loud instruments (drums, whistle, recorder head, ratchet etc. ), traveling in noisy transport (train, bus, car, plane, motorcycle), with snoring bed neighbors or other sleep-disturbing environmental sounds, New Year's firecrackers, Carnival, shooting sports, motor sports events and etc.

Evaluation of the insulating value of ear protection

The insulation of ear protection is a maximum of about 25-40 dB, where it is ultimately highly frequency -, material- and anatomy -dependent. To achieve higher insulation values ​​, a to in-ear hearing protection system (Otoplasty or bud) can be combined with ear muffs.

The after a test standard approved for the labor protection ear muffs are always brought with details of their insulation properties ( HML ) values ​​in the market. To simplify comparison of different products, a damping value is specified, which indicates the average loss over the relevant frequency range, and therefore only the approximate orientation and for easy comparison of different damping means is useful. Condition and use of ear protectors have a decisive influence on its effect in the application. Also, different damping means differ significantly in terms of the effect at different frequencies.

In practice, a trigger from the specified attenuation value is made ​​in comparison with already safety reasons. This deduction is for:

• Plugs 9 dB ( A)

Hearing Protection for the visitors of events is governed by the permissible sound level in DIN 15905-5. The public may be exposed in Germany average levels of 99 to 100 dB ( A).

These are often not respected. In recent years, the levels have been sentenced in hearing damage incurred to pay damages variously organizer for non-compliance.

According to the regulations of the trade association applied for the selection of hearing protection plugs and caps, as equivalent. As of 80 dB ( A) the wearing of hearing protection in the workplace is recommended from 85 dB ( A) it is prescribed.

Hearing protection types

Earmuffs

Especially short term use (eg in building construction ) used a ear muffs. This is the case of closed headphones similar, circumaural capsules that can be easily and at any time created and removed again. The ear is completely enclosed with such equipment from a hard plastic shell which is padded at the contact point and otherwise lined with sound-proofing and polsterndem foam. They are available in the version with a headband, neckband and universal bracket which can be worn both on top and in the neck. The universal bracket is additionally provided with neck wear fashion with a headband for better fixation of hearing protection. This type of ear protection is based on the division of the German Social Accident Insurance to the "conventional earmuffs ".

Another type is the " special earmuffs ". This can be prepared in the form of a level-dependent insulation, with a communication device, Active noise reduction or a radio. In the level-dependent damping, a microphone is mounted on the outside of the earmuff, which receives the ambient noise, processed by a small amplifier and supplies the interior of the capsule through a small speaker. The amplifier has a built-in, very fast control, the. Sounds only up to a certain volume level ( in Germany 85 dB ( A)) processed (peak clipping [PC ] Automatic Gain Control [ AGC] ) A loud bang, for example, is thereby effectively insulated; Calls are still possible. This system is, for example, at shooting ranges police, used in teaching the practical use of weapons or even in hunting, where the hunter is dependent on the acoustic perception of the environment. With ear-muffs communication device, a speaker is installed in the capsule, so that instructions and other communications, such as a cable or a wireless device despite hearing protection and ambient noise can be understood. It may also be the support given the opportunity to talk through a microphone attached to a bracket itself. Earmuffs with radio receiver are built basically the same, but they contain an FM receiver. In both species the level of the speaker to 82 dB ( A) are limited.

" Ear muffs in combination with other personal protective equipment " include provided for mounting to helmets and form in Germany, the third type of ear muffs.

Earplugs

Prefabricated Earplugs are also known as ear plugs or ear plugs. Colloquially, they are often referred to simply as the manufacturer of the widely used product " earplugs ".

In Germany, from the statutory accident insurance in

• Ready-formed earplugs including hearing protection ear molds,
• Before use to be molded earplugs and
• Strap pegs.

Distinguished.

Before use, to be molded earplugs are made of wax- impregnated wool, silicone, foam and can be used multiple times or once, depending on the type. The wax balls made ​​by kneading soft, coarse pre-formed and then inserted directly into the ear canal. They deform slightly when inserting and removing. The cleaning is not usually possible. Foam earplugs are first rolled and then inserted into the ear canal where they expand. Ready molded earplugs are made ​​of soft plastic ( fin design). They are completely formed and must only be inserted into the ear canal. However, depending on the size and shape of the ear canal plastic plugs can be audiologically unsuitable and uncomfortable. Both types can be connected to a neck strap, finished molded earplugs with a plastic strap ( strap pegs ). Through the clamp, which can be worn on the neck under the chin or above the head, produced only a slight feeling of pressure in the ear canal and ear protection can be easily used. Strap pegs are used primarily as ear muffs.

These designs are relatively inexpensive and therefore very good for the irregular use. However, they are not very durable; especially the remarks made ​​of foam and wax are quickly contaminated with earwax and should therefore not be used for long. Furthermore, the foam loses its ability to adequately expand again after rolling together to seal the ear canal.

When a maximum sound absorption is desired, it may, from audiological point of view, come with the use of any such protectors to " operator error ", as the depth at which the hearing protection is located in the ear canal, can be determined at the onset itself. The depth at which the hearing protection sits in the ear, namely determines how large the remaining air - residual volume in the external ear canal between the eardrum and ear protection is - the smaller this volume is, the higher the possible sound insulation.

Earmolds

Besides the use of industrially produced earplugs, it is also possible to leave with a hearing aid acoustician make a personal hearing protection as otoplasty. For this purpose, the hearing care professional may take an impression of the external auditory canal and part of the auricle to customize a Maßohrstück it.

As materials for ear devices can be used:

• Silicone: soft plastic - easy to clean - long life - very comfortable to wear, because the ear mold the movements of the ear canal adapts ( talk / laugh / chewing movements ).
• Fotoplast: hard plastic - better quality material than acrylic because it contains less residual monomers and the shrinkage rate is lower.

The hearing protector may be provided with a handle for ease of insertion or by a joining tape. The color of ear protection can be individually selected, to the extent permitted by the material used.

The seat depth of hearing protectors in the ear and the resulting residual volume between the eardrum and ear protection is the same when using a custom-made hearing protection at each insertion, the insertion errors as with other earplugs can therefore unlikely to occur.

As with other types of hearing protection can cause distortion in the sound, as it depends on the material the different frequencies and sounds are different degrees insulation, which can be detrimental particularly when used by musicians. In certain designs can acoustic filter into the ear mold, partly for self- change, are used. These filters regulate the insulation of hearing protection and can also ensure depending on the filter type that the so-called linear sound remains.

A disadvantage of the individual hearing protection is the substantially higher price (up to 200 € per couple ), which can be qualified according to the material by a longer life but. The very high wearing comfort due to the adaptation to the anatomical conditions of the support and the ability to change filters advantageous earmolds to be used, thus allowing to adapt to the prevailing conditions (eg strong or weak damping, linear damping).

The around 15 euros per ear cheapest method is the production of ear protection made ​​of addition silicone which, after casting of the ears, which takes about 15 minutes, can be completed within 20 minutes directly to the retailer. However, this variant has a somewhat shorter life than coated silicone variants. All other materials with a negative mold of the ear mold has to be prepared prior to the actual manufacturing of the ear device. As this takes more time and the materials are more expensive, the price of any such protectors is higher.

Hearing protection ear mold made ​​of transparent acrylic

Hearing protection Schmuckotoplastik of acrylic with rhinestones

Hearing protection earmolds with filter element

Ear molds made ​​of silicone can also be used for protection against water at tympanic membrane or of carriers of tympanostomy tubes. However, it must be ensured that must not be immersed with a hearing protection and the eardrum is intact. Because with increasing ambient pressure under water the pressure balance of the in- ear air remaining volume is hampered by the surface transformation between outside and inside of the ear protection and strong sealing the ear canal and it threatens a Trommelfellriß.

Emergency plugs of pulp ( as individual -made )

In acoustic emergency situations (night clubs, air travel, etc.), it is possible themselves (eg pulp tissue or toilet paper ) to produce effective hearing protection from pulp. For this first one rolls a 2 cm wide strip of cellulose to form a cylindrical rolls with about diameter of the ear canal. By humidities (eg saliva) and kneading (eg with the teeth ) makes this roll malleable and soft. It can then push well into the ear canal. Body heat dries out within a short time of cork and forms with proper output a good custom paper Machee - stopper. The achieved soundproofing here depends largely on the depth of insertion. From an aesthetic and hygienic point of view it is not recommended to the multiple use of own products.

Sound protection suit

Higher insulation than with a conventional hearing protection can be achieved only by special soundproofing suits of textile - leather combinations. The reason for the limited maximum insulation of an ear plug or hearing protection capsule is that the inner ear and the sound waves recorded, taken over the body. The airborne noise will sound body, spreads throughout the body and is passed via the skeletal apparatus to the inner ear, which is embedded in the skull bone. Hence, to achieve a very large insulation, the structure-borne noise must be prevented over a large area and thus the human being encapsulated by a sound protection suit of the environment. Also may be caused by the sound pressure and balance disorders. The use of such a suit is useful from time noise levels of about 125 dB. They can be found at airports or in the army. It is worn in combination with a suitable hearing protection.