Yesterday, a hearing loss patient asked to wear a bone conduction hearing aid; this situation is not common, so I asked him: “Why do you know the bone conduction hearing aid? Do you understand it?” The other party shook his head and said: “This is my friend’s introduction. I said that I can wear it very well.” So I started to introduce him to a bone conduction hearing aid: not for everyone.
Bone conduction hearing aid style
In the professional hearing aid fitting center, the common types of hearing aids are: behind the ear and in the ear, but these are all air-guided hearing aids. So is the bone-guided hearing aid the same as the air-guided hearing aid? In fact, they are different.
Common styles of bone conduction hearing aids are: glasses type, collapse type, head clip type. This type of machine is non-surgical and can be selected at some hearing aid fitting centers.
Bone conduction sound
Usually the sound we hear in the human ear is collected through the auricle, transmitted through the outer ear and the middle ear, and finally felt by the inner ear, and then transmitted to the auditory cortex through the auditory nerve, etc., to produce hearing. How does bone conduction make us hear the sound?
The bone conduction hearing aid amplifies the collected sound, converts it into an electrical signal, converts the electrical signal into mechanical energy, directly vibrates the skull, transmits the vibration to the cochlea, and finally the inner ear cochlea feels the sound and transmits it to the auditory cortex through the auditory nerve. The sound was heard by us. The transmission of sound does not need to pass through the auricle, the external auditory canal and the middle ear, which is an important difference from air conduction.
Air conduction hearing aids are different in style, or the host is hung behind the auricle, or the whole machine is stuffed into the external auditory canal. The wearing method is simple, easy to use, good concealment and good comfort.
The vibrator of the bone conduction hearing aid must be close to the skull and pressed vertically on the surface of the skull, usually placed in the mastoid, or placed in other parts of the skull; it does not need to be in contact with the auricle, the external auditory canal, etc.; the concealment is poor, Comfort is also poor.
Like air-guided hearing aids, bone-guided hearing aids have a design life of 5-8 years and are also available for long-term use. Only long-term use of bone conduction hearing aids will make the skin in contact with it hard and the contact area is painful; for 3000-4000Hz and above, it provides little amplification (and air conduction hearing aids can be used at frequencies within 125-10000Hz). Magnification processing, wider bandwidth).
Due to its poor sound source positioning, small sound output, narrow frequency range, many distortions, inconvenient to wear, uncomfortable and other shortcomings, it is rarely used clinically; it is not common in the fitting center.
Special bone conduction hearing aid
The bone-fixed hearing aid (BAHA) is a special type of bone-guided hearing aid. It also transmits sound by vibrating the skull. The difference is that it requires surgery to implant a titanium screw in the mastoid, and then attach it to the vibrator. The vibration is transmitted to the skull to make people hear the sound; the skin does not become hard and tender, and the wearing comfort is slightly higher and more beautiful.
Who applies bone conduction hearing aids
The bone conduction hearing aid is suitable for a small number of people, usually used for: conductive hearing loss, congenital external ear hypoplasia (such as external auditory canal atresia, stenosis, etc., or ear deformity), and some of the external ear, middle ear disease ( Such as chronic suppurative otitis media long-term recurrent pus) is not suitable for patients with air-guided hearing aids.
1. The power of traditional non-surgical bone conduction hearing aids: the average value of bone conduction is less than or equal to 55 dB HL; the wearing effect will be affected by different thickness of skull, different thickness of scalp lower fat, and different wearing positions.
2. The power of surgically implanted BAHA: the average value of bone conduction is less than or equal to 65 dB HL; such hearing aids have wounds on the outside of the skull, and daily care needs to be paid more attention to hygiene and dryness to prevent infection.
Jinghao medical hearing aid reminder: hearing aids need to be professionally “fitted”, it is very important to choose a professional hearing aid fitting center and hearing aid fittings! All patients and friends have any hearing problems can call the Jinghao medical consultation, or personally Come to the fitting center experience. Hearing aid free consultation phone: +86-18566295705
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