Hearing loss and Types

In a normal ear, the sound hits on an intact eardrum. Three small bones work as a lever mechanism to increase the movement, and the third bone (stapes) works as a piston to convey this amplified vibrations to the fluid system of the inner ear. Some mechanical problem, such as fluid in the ear, perforation of the eardrum, or damage to the lever mechanism of the three bones which amplify the sound, or fixity of the eardrum or the bones or piston or new bone formation may result in a hearing loss, where the amplified sound is not reaching the inner ear. However, if the inner ear is stimulated directly by the bone, the nerves, hearing organ and hearing is normal. This is called conductive hearing loss. This is often reversible, and may be corrected by surgery.

Here there is a damage to the inner ear (sense organ), or damage to the auditory nerve which conducts the signals to the brain (Neural Hearing Loss). These occur when there is physical or other damage to the end organ or the nerve. Mostly sensory-neural hearing loss is not reversible (except for sudden onset hearing loss due to certain causes). No surgery can correct this loss and a hearing aid is the only solution. Sudden onset sensory-neural hearing loss can be due to a viral infection, or a “mini stroke”: blockage of blood supply. This can be reversed by urgent medical management.

Is a combination of conductive loss, with sensory-neural loss also present. The conductive part may be correctable. Screening for hearing loss is now recommended in all newborns. In children, hearing problems may cause speech to develop slowly, along with other learning handicaps. By early screening, congenital hearing loss (sensory-neural hearing loss present from birth) can be detected early and suitable measures like Hearing aids, or cochlear implantation can be done at an early age, so that the child does not also become mute. In childhood, ear infections are the most common cause of temporary hearing loss. Fluid can linger in the ear following an ear infection. Although this fluid can go unnoticed, it can cause significant hearing and learning problems. Any fluid that lasts longer than 8-12 weeks is cause for concern, and needs to be treated by a minor surgery to drain the fluid. In this surgery, electrodes are inserted into the inner ear, and the hearing aid (speech processor) fitted behind the ear thus sends electrical signals straight to the hearing nerves. This is not suitable if the nerve itself is damaged. The implant is very expensive  and has its own share of complications.

Which Hearing Aid Type is best for you?

There are many hearing aid types, features, prices and styles to consider. When determining which hearing aids are best for you, you need to consider various factors to ensure you make the right choice. The following is a guide on the most important considerations you need to take into account when you are considering your hearing aid choices. Not all hearing aids are suited to all hearing losses. You need to consider the type of hearing loss you have, the extent of loss (how bad your hearing is), and the configuration of your hearing loss (what your test results look like). The configuration of hearing loss is usually the main consideration when a particular style is recommended to you The most common hearing loss configurations are a sloping loss and a flat loss.

The sloping hearing loss is the most common configuration seen by audiologists. These types of losses are common for those suffering presbyopia (age-related hearing loss), or noise induced hearing loss. Broadly speaking, hearing aid style can be broken up into two categories, behind-the ear and in-the-ears styles. Behind-the-ear (BTE) Australian Hearing aids come in a few sub-categories, Standard, Open fit, and receiver in canal. They all are comprised of the hearing aid which sits behind the ear, and something which delivers the sound into the ear canal. Open fit BTE’s are designed for sloping losses. They reduce the amount of occlusion effect the wearer may experience, and will minimize the adverse effect (echo, loudness) of your own voice that you perceive whilst using the hearing aid. People with sloping losses are most susceptible to this effect, which and is a high area of concern for hearing aid users. The drawback of open fit hearing aids is the higher risk of acoustic feedback (or whistle) which the user may experience.

If you have hearing loss which goes into the moderately-severe range, you may be best suited to a standard BTE. This will minimize feedback whilst leaving the ear canal as open as possible through venting of the ear mold. Cosmetically, the open fit BTE or RIC aid are the most appealing on the market, particularly if the wearer has hair covering the behind the ear part of the device. Receiver-in-canal (RIC) hearing aids share almost all the beneficial properties of open fit aids, but often have a larger volume range before feedback is an issue. These hearing aids are now some of the most popular on the market. They have the same cosmetic appeal as open fit BTE’s, and are able to fit much more severe losses than them.