Deafness

To understand deafness, you must understand that it is the lack of sound, due to damage within the ear. Another student group has produced an excellent website about it. First sound is the result of air particles moving in the air, for example look at violin and how the string vibrates. Second, the sound waves hit your ear and excites your eardrum and other portions of your inner ear. Then this vibration gets translated into electrical signals by hair cells, which act like little neurons and then go to the brain for processing. This signal travels through various parts of the brain and get processed into pitch, timbre, volume, and all the other parts of sound. Damage to any of these pathways can create deafness.

What is deafness?

What is auditory deprivation?

What are some treatments?

Where is some information on hearing aids?

What is ABI?

Useful links

Deafness refers to the inability to hear. Approximately 1 out of 12 Americans have hearing problems (http://www.cdc.gov/nchs/). The causes for deafness can be hereditary, accidental, or due to illness. The inheritance of hearing loss is due to certain genetic factors, complications or viral infections the mother may have had during pregnancy. It does not, however, mean that either of the parents had to be deaf. Accidents may include high noise levels which damage the ear drum, physical damage, or drug effects. Illnesses which may cause deafness are tumors and lesions.

The Auditory deprivation effect occurs when there is a lack of adequate auditory stimulation. The neural pathway which is involved in this process gradually dies off when it is no longer used. Studies have shown that those who wear only one hearing aid end up with reduced speech recognition ability in the unaided ear. One may wonder what the effect of auditory deprivation is on those looking to receive cochlear implants. The central auditory system changes in response to auditory deprivation and it can continue to change and reorganize itself for a number of years. Young children are more adaptable in this sense. The plasticity level in their central auditory system, as well as their ease of learning allows them to obtain significant benefits from cochlear implants.

There is not yet a cure for deafness, but there is the possibility of a cochlear implant. Early detection of deafness can help in coping preparation and a reduction of the stress level. Sign language is a form of communication which helps to integrate them into the hearing community.

Hearing aids are electronic devices used by those who have a hard of hearing by selectively amplifying weak sounds through a speaker. Due to modern technology, hearing aids can also moderate loud sounds. The basic parts to a hearing aid include a microphone, an amplifier, a receiver to deliver the sound into the ear, and batteries. Based on the different needs of various people, hearing aids have adjustable amplification, volume control, a variety of special features, and they come in different sizes and designs.

An auditory brainstem implant (ABI) directly stimulates the brainstem’s auditory processing centers (depending on the type and sophistication, it can stimulate either the surface or deeper into the ventral cochlear nucleus). For those people who are not eligible for the cochlear implant because their auditory nerves are damaged or absent. this means that they may still be able to benefit from an ABI. The basic design of an ABI is similar to a cochlear implant: there is an external speech processor that translates the sound into electrical impulses that stimulate the ventral cochlear nucleus by means of an electrode array. The current models of ABIs do not allow for a wide range of frequency to be heard (the “sound” range would be similar to that of a single channel cochlear implant), making it very difficult for speech to be understood.

If a person is deaf for many years then the lack of stimulation can cause the auditory nerves to start deteriorate: in this case a cochlear implant is no longer an option, but a person may still be assisted with an ABI because the brain and brainstem is intact.

Also, there are a number of services, clubs, and organizations which act as support groups: