The role of air hole in hearing aid

Many customers don’t understand why we need to add air vent. They think it’s not good, and it’s easy to be blocked by earwax. In fact, it’s a misunderstanding! The air vent of hearing aid is to change the frequency response of hearing aid The frequency response of hearing aids can be changed by their own fine-tuning. However, when some hearing aids do not have fine-tuning or it is difficult to achieve a desired frequency response by fine-tuning, they can be improved by different forms of vents Even if the air vent is very small, it can relieve the feeling of fullness and pressure in the ear Keeping the ventilation between the ear canal and the outside can reduce the dampness in the ear and the possibility of secondary infection.

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Reduce ear blocking effect. The ear blocking effect can make the patient feel that his voice is very loud and empty, just like talking in a bucket. This is because after the ear canal is blocked, the patient’s own voice can enhance the low-frequency voice through the bone conduction function. Compared with normal hearing, the blocking effect mostly occurs below 500Hz.

To reduce low frequency gain, low frequency sound usually needs to be reduced, because patients do not need too much low frequency compensation. The decrease of low frequency can increase with the increase of vent diameter. When customizing the ear mold, in addition to the severe deafness, you generally need to customize the air vent. If not, you can also plug the air vent. However, if the acoustic hole of the ear mold itself is very long, the frequency response of the hearing aid will not be significantly changed due to the size of the air hole, because at this time, the frequency response of the hearing aid mainly depends on the acoustic hole.

The size of vent: the size of vent mainly depends on the balance between howling and ear blocking and the size of ear canal. Whistling (sound feedback) is due to the amplified sound returning to the microphone, which makes the microphone lift the amplified and UN amplified sound at the same time, causing resonance at a certain frequency, so the producer produces audible whistling, even if the sound cannot be heard, it is also a distorted amplified sound. When there is an audible howl on the real ear, it often changes due to the wearer of the hearing aid, the type of the hearing aid, the ear mold and the size of the air hole. The possibility of whistling will increase with the increase of vent.

Type of air hole: parallel type: the diameter of the hole parallel to the acoustic hole can be large or small, but it is limited by the volume of the ear mold itself. Side branch type (type): This is the hole intersecting with the acoustic hole in the ear mold. This kind of vent can also reduce the gain on the high frequency (the frequency above 1000Hz can be reduced by more than 10dB), which is generally not used. Outer edge vent hole: when there is not enough space to drill the inner vent hole, drill the vent hole along the edge of the ear mold outside the ear mold.

So vent is very important. We should understand its use and the benefits it brings to me!

Jinghao hearing aid reminder: hearing aid wearing requires professional “matching”, so it is very important to choose a professional hearing aid matching center and a hearing aid tester! If you have any hearing problems, you can call Jinghao for consultation, or come to the matching center for experience. Hearing aid free consultation Tel.: + 86-18566295705