An audiology exam, admini¬stered by an audiologist, tests the ability to hear sounds. Sounds differ according to their volume or loudness, usually called intensity, and the speed of sound wave vibrations, or tone. Humans hear when sound waves are conducted to the nerves of the inner ear and from there to the brain. Sound waves travel through the ear canal, eardrum and bones of the middle ear (air conduction) or through the bones around and behind the ear, also known as bone conduction.

The intensity of sound is measured in decibels, with a whisper being about 20 decibels, loud music 80 to 120 decibels, and a jet engine being 140 to 180 decibels. The normal range of human hearing is from 20 to 20,000 decibels. Some animals can hear up to 50,000 decibels. Tone is measured in cycles per second, or Hertz. Low bass tones range from 50 to 60 Hertz, and shrill, high-pitched tones range 10,000 Hertz or higher. Sounds greater than 85 decibels can cause hearing loss in a few hours. Louder sounds than that can cause immediate pain, with hearing loss developing a very short time after. Normal hearing is considered to be the ability to hear a whisper, normal speech and the ticking of a watch; ability to hear a tuning fork through air and bone; and if tones of 250 through 8000 Hertz can be heard at 25 decibels or lower. Most loss of hearing occurs because of trauma at birth, viral infections, genetic disorders, exposure to loud noise, certain medications or due to the aging process. Treatment of hearing disorders can range from cleaning the ear canal to fitting and programming cochlear implants (an electronic device implanted in the skin behind the ear to help people who are profoundly deaf or hard of hearing). Noise, aging, disease and heredity have made hearing loss a common problem in our society. Our sense of hearing involves both the sensitivity of the ear as well as the ability to understand speech. A hearing loss professional must consider many factors in order to determine hearing loss, the type and degree of the loss, the area of abnormality in the auditory system (middle ear, inner ear, brain), noise exposure and age. The kinds and degrees of hearing loss can be very complicated to measure and quantify. Some people suffer the loss of the ability to hear high or low tones, or loss of only air or bone conduction. If you cannot hear pure tones below 25 decibels, it indicates some degree of hearing loss. As a result of a hearing test, other conditions may be uncovered and treated, for instance, acoustic neuroma (a benign tumor of the ear), acoustic trauma (injury to the hearing mechanisms within the inner ear caused by excessively loud noise), age-related hearing loss, alport syndrome (a genetic disorder involving progressive loss of kidney function and hearing), labyrinthitis (inflammation of the inner ear structure), Meniere’s disease (abnormality of the inner ear that causes vertigo and dizziness, among other symptoms), occupational hearing loss, otosclerosis (abnormal growth of bone in the ear resulting in hearing loss) or perforated eardrum (the presence of a hole in the eardrum).

The range of hearing tests runs the gamut, from a simple screening where a loud noise is produced and the subject is observed for startle response, to the BAER, or brainstem auditory evoked responses test, where an electroencephalogram detects brain wave response to sounds. Closely connected to the way the human ear functions is the human balance function, or our ability to move about without falling over. Diseases of the inner and middle ear can cause problems with balance that affect how a person lives. Severe balance problems can result in some patients being afraid to leave their home for fear of falling. Healthcare professionals who deal with hearing loss also help patients with vertigo and other balance difficulties. About 28 million Americans have some hearing problems. This is double the number from 30 years ago. Ten million Americans have hearing loss caused by noise, and 30 million more are exposed to dangerous noise levels each day.

Seventeen out of every 1,000 children under the age of 18 have hearing loss. At the other end of the scale, 314 in every 1,000 people over age 65 have hearing loss, and half of all people 75 and older have hearing loss. If you have hearing loss, you may not understand what someone is saying to you. You may be unable to fully experience meetings, movies, parties, theatrical performances, or religious services. Your friends and family may become frustrated because of how difficult it is to communicate with you. Some research indicates that earing loss results in depression.

Audiologists diagnose, treat and manage individuals with hearing loss or balance problems. They develop hearing conservation programs to help people prevent hearing loss through education, noise level monitoring and hearing monitoring. They identify possible hearing loss through hearing screen tests. Audiologists are experts in the non-medical management of the auditory and balance systems. They concentrate on the areas of normal and impaired hearing, prevention of hearing loss, identification and assessment of hearing and balance problems, and the rehabilitation of persons with hearing and balance disorders. After diagnosis, the audiologist must assess the nature and extent of the problem using audiometers, computer and other testing devices. Such devices determine the loudness level at which the individual begins to hear sounds, the ability to distinguish between sounds, and the impact of hearing loss on the person’s daily life. The need for skilled audiologists has grown and continues to grow very rapidly. Everyone knows that healthcare in general is one of the fastest growing employment opportunities. New developments in medical treatments mean more people are coming under the regular care of physicians and specialists. The aging population demands its own specialized approach to medicine. And the increase in chronic illnesses has driven the need for long term care facilities and caregivers. There are many more healthcare specialties today. Where there used to be only general practitioners, eye specialists, surgeons and nurses, now there are doctors who specialize only in heart s surgery or gastroenterology, ear/nose/ throat doctors, as well as neurosurgeons. This splintering effect has filtered down to the realm of nursing and other healthcare professionals, offering opportunities for rewarding careers in a number of specialties, even for those who do not want to be medical doctors. The audiologist falls into this category, a healthcare specialist who addresses an important human need, using specialized education and experience to contribute to overall health.