Who - People with hearing impairment
To be able to hear well, the entire trajectory, from ear canal, eardrum, middle ear, cochlea and auditory nerve up to and including the cerebral cortex, must function properly. In the first part of the trajectory, up to and including the middle ear with the ossicles, sound vibrations are transmitted. Hearing impairment in this part of the trajectory is called conductive hearing impairment.
1.6 million Dutch people are hard of hearing. That is almost 10% of the population. The largest group consists of the elderly. In addition, of all the over-85s in a care home, one in thirteen elderly people is both hard of hearing and visually impaired. In nursing homes this is even one in five elderly people. Due to the increasing aging of the population, the number of hearing impaired people will increase in the future. Hearing impairment is also common in people with intellectual disabilities and in severely disabled people: almost one in three people with intellectual disabilities has hearing impairment. For people with Down syndrome, that is even more than half. Hearing loss is usually also more severe in people with intellectual disabilities.
Causes and types of hearing impairment
To be able to hear well, the entire trajectory, from ear canal, eardrum, middle ear, cochlea and auditory nerve up to and including the cerebral cortex, must function properly. In the first part of the trajectory, up to and including the middle ear with the ossicles, sound vibrations are transmitted. Hearing impairment in this part of the trajectory is called conductive hearing impairment. Sound is mainly perceived softer. Electrical incentives are transmitted in the second part of the route. A hearing disorder in this section is called a perception disorder (perception disorder). Sound is hereby softer or, on the contrary, louder, distorted and sometimes perceived with noise. It is harder to distinguish details in the sound. People are therefore less able to understand speech if there are noises in the environment.
As you age, the hearing gradually deteriorates. This age-related hearing impairment (presbyacusis) is usually about perception or hearing impairment. People with Down syndrome often have hearing impairment at a young age; from the age of 35, age-related hearing impairment is added.
What do the hearing impaired hear?
That is different for every hearing impaired. Examples can be heard at http://www.oorcheck.nl/gehoorschade/hoe-ontstaat-schade/zo-klinkt-het/.
It is not even the most annoying thing that hearing impaired people do not hear soft sounds properly. The biggest problem is that they have more difficulty understanding what others are saying (understanding speech). That is because of two things. First, the hearing threshold has been raised: what others say is often too soft to be able to understand properly. This is especially the case with hearing impairment.
In the case of perception or perception impaired hearing, people are at the same time hypersensitive to loud sounds. This is called recruitment. This makes it more difficult to see details from the whole of sound. Understanding a conversation when there are other sounds (large company, radio, hum of an air conditioner) often fails. In addition, sound is distorted. Sometimes the hearing impaired spoken words can hear, but cannot understand.
Living with hearing impairment
The hearing impaired and the deaf depend on visual information. The hearing impaired pay attention to body language, but sometimes misinterpret it. They do not hear when their name is announced in the waiting room of the practice or in the pharmacy. They don't hear you coming and can't hear who you're talking to. When people around them have fun, a hearing impaired person can easily think that they are laughing at him. He misses a lot of information that you, as hearing, catches casually, at the coffee machine, on the bus, in the break, at a meeting or party (see videos on www.zie-zo.nl). The hearing impaired is partly dependent on others for his communication. He often has to ask the other person to repeat something or to look at him when he talks. Listening takes a lot of energy.
Sign language is the first language that a deaf child learns. Spoken and written language is a second language for deaf children, just as English is a second language for the hearing impaired. They often do not control them well; it is more difficult to indicate nuances.