Recruitment

Recruitment is a condition commonly associated with the discomfort of hearing loss. The condition of recruitment is experienced by people who have hyper-sensitive ears and are unable to tolerate ordinary levels of noise.

Recruitment patients often find normal loudness of sounds extremely painful and too loud for their tolerance. Often with an older person, having difficulty in hearing they would say "Speak up a bit... I can't hear you" and then after you speak up they say, "Don't shout! I'm not deaf".

Hearing becomes impaired, due to the loss of tiny hair cells in the inner ear, called the cilia. This can be caused by a high frequency sounds such as bird calls, a telephone ringing, loudspeakers, sirens or car horns. Recruitment can mean any of the following:

• A collapse of loudness tolerance
• An increase in the response and a decreased number of neural elements to a sound stimulus
• The feeling of the distortion of loud sounds

A person with recruitment may not be able to hear high frequency sounds, below 50dB (decibels), but may find any sounds above 80dB uncomfortable and liable to produce distortion.

Recruitment is usually due to a reduction in neural elements in the inner ear (the hair cells), a small change in the stimulus intensity produces a bigger change in response of the inner ear. More of the nerve fibers are switched on "'recruited" for a corresponding sound stimulus.

Noise that contributes most to hearing loss and ear infections are environmental. There are different sources of noise in our environment that can contribute to one's condition of Recruitment or intolerance of normal sounds or noises... These sources are daily activities that cannot be eradicated, but they can be avoided in most cases:

• Various kinds of Traffic noises - This include day to day noise from automobiles, police or ambulance sirens, motor vehicles, aircraft, railways and ships etc.
  
• Workplace and Industrial noise - This includes noise caused by computers and other machinery at work, as well as noise radiating from industrial plants and building sites in the neighborhood.
  
• Noise from the residential and leisure activities e.g. - noise from radios and TVs, telephone ringing, or sound emanating from leisure activities (e.g. from sports, music events, shooting practice, toy pistols and fireworks).

Who is more likely to get recruitment?

Recruitment or hearing loss is often associated with old age and exposure to high noise levels. However, anyone who gets excess noise exposure may have their inner ear damaged, which may result in impaired hearing.

Most young adults are said to get too much exposure to noise due to certain activities that are often associated with high sound levels. These high levels of noises like loud earphones (portable music player) may cause as much damage to one's hearing as those encountered in the workplace.

Toys that make too much noise and electrically amplified games like playstation2 can make as much noise as workplace machines. This causes even young babies to have as much exposure to high noise levels as adults. In most cases babies are said to have a higher tolerance level to noise than adults. This is due to the fact that they develop it from young age and learn to live with it as they grow.

Anyone working in a noisy environment must wear ear protection to lessen the possibilities of having their inner ear damaged. People who work with loudspeakers like Disc jokies are more likely to experience ear infection if they disregard ear protection.

Topics that may be of interest on ear or hearing problems:

A person that is hard of hearing may have both recruitment and hyperacusis at the same time.

Hyperacusis is defined as a reduced tolerance to normal environmental sounds while everyday sounds are unbearably or painfully loud. People with hyperacusis feel as though the volume control in their brain is stuck on HIGH! It can also be known as any of the following:

• Dysacusis
• Oxylacusis
• Hypersensitive hearing
• Phonophobia

Click on each of these topics to learn more:

1. Vertigo
2. Hyperacusis
3. Meniere's disease
4. Tinnitus