Human Hearing Aid
Patients with a conductive defect which does not respond fully to treatment may be helped with a hearing aid.
A hearing aid is an electronic, battery-operated device that amplifies and changes sound to allow for improved communication. Hearing aids receive sound through a tiny microphone, which then converts the sound waves to electrical signals. The amplifier increases the loudness of the signals and then sends the sound to the ear through a speaker in an ear piece which fits into an outer ear canal. The electric signals are converted back to sound waves.
A volume control on the aid usually operated by turning a tiny wheel enables the level of incoming sound to be adjusted.
More powerful aids that amplify sound to a greater degree are available. In these aids the microphone, amplifier and battery are contained in a larger case worn on the body; the currents is carried to the ear piece by a thin wire. Some people with conductive deafness especially if there is an infection or discharge in the ear canal may be given a bone condution hearing aid. This type of hearing aid may be fitted to a glass frame or hair band.
Other devices available for the hard-of-hearing include amplified telephone receivers, flashing lights instead of door bells and telephone bells, vibrators that respond to sound, head phone for television sets, teletype writers and guide dogs for the deaf.
The term noise is derived from the Latin word Nausea refering to the feeling of sickness in the stomach with an urge to vomit. Any unpleasant and unwanted sound is considered as noise. It is one form of pollution. Noise pollution can be defined as unwanted or offensive sounds that unreasonably intrude into our daily activities. It is responsible for various adverse effects. In recent years noise is recognized as a major pollutant on par with other chemical pollutants of air, water and biosphere. Noise has many harmful effects on man and the damage incurred is irreversible.