It is common for people to not always hear everything that is said to them. If this occurs frequently, causes embarrassment, or interferes with job performance, you may want to have your hearing tested to see if there is a problem. A hearing evaluation (audiogram) will determine how well you can hear sounds of different frequencies, as well as, how well you can understand speech. Hearing exams are conducted in a sound treated booth to minimize the interference of outside sounds.
The appointment typically takes between 45 minutes and one hour. A complete history of your hearing problem and hearing health is conducted. The audiologist then examines your ears with an otoscope to check for things like excessive ear wax, problems with the ear drum or middle ear fluid. Once the otoscopic exam is completed, you will be placed in the sound booth and ear phones are placed on your head. Pure tones are presented at various frequencies or pitches to determine the softest level that you can hear (threshold). These threshold values are plotted on a graph which is called an audiogram. Thresholds measured with earphones are called air conduction scores and represent how well the whole ear (outer ear through inner ear) works. These values are compared to bone conduction thresholds. Bone conduction thresholds are measured the same way as air conduction thresholds, but instead of using eaphones, a bone oscillator is placed on the mastoid bone behind your ear. When the pure tone signals are presented through the bone oscillator, the vibrations of the mastoid bone lead to perception of the tones just as when earphones are worn. Bone conduction measures essentially test the inner ear directly. By comparing how softly you can hear air conducted signals to how softly you hear bone conducted signals, we can determine where in the ear your hearing problem lies. Conductive hearing loss occurs when the outer ear, ear canal, ear drum or middle ear do not transfer the air conducted sound to the inner ear. In most cases this type of problem can be treated with medicine or surgery by your physician. Unfortunately, approximately 90% of hearing losses are the other type which involves damage to the inner ear structures or the hearing nerve itself. These types of problems cannot be treated with medicine or surgery, but, in most cases, hearing aids can offer considerable help.
Other measures are often used during the evaluation to study the function of your ears such a tympanograms and stapedial reflex studies. Tympanometry is used to determine if pressure or fluid exists behind the ear drum. Stapedial reflex testing examines the function of the muscles of the middle ear. Stapedial reflex measures give information regarding the middle ear muscle function which can be helpful when assessing a person with facial nerve paralysis (Bell's Palsy). These measures can also be used to estimate hearing ability in patients who are not capable of taking a traditional hearing test. A third use of stapedial reflex testing is to screen for pathology of the hearing nerve.
Distortion Product Otoacoustic Emissions testing gives us a measure of the functional integrity of the receptor cells within the inner ear (cochlea). This measure, like tympanograms and stapedial reflex studies are objective tests of ear function which can be very helpful when we are unable to obtain behavioral hearing data.
Once all of the data are collected, the audiologist will thoroughly discuss the results with you. Treatment options will be discussed and and if appropriate, recommendations will be made. This is a time when hearing aids will be discussed to determine what may offer the best help for your particular problem.
Pediatric Hearing Tests
Hearing is an essential factor in a child's speech and language development. If they are not hearing well, speech, and more importantly, language is very often delayed. It is important that any hearing impairment is detected at the earliest possible age so that intervention can start. The earlier the intervention, the better the chance that normal speech and language will occur.
It is hard for most parents to accept that their child has a hearing impairment, realizing that your child will have a significant challenge to deal with. So it is not unusual for the parents to be in denial and do nothing thinking that their child "will grow out of it."
Hearing loss is not cause for despair. There is no reason why a child with hearing loss should not have a good childhood and develop quite normally. Just remember to take one step at a time. Your doctor, your audiologist and other skilled professionals will be able to advise you on how to best help your child. The process begins with a thorough hearing evaluation. There are several ways to assess hearing in children, even in newborns. The following section details hearing evaluations we use at Tennessee Valley Audiology to test children's hearing for ages six months and above.
Visual Reinforcement Audiometry: For our younger patients (six to twenty-four months) we typically use visual reinforcement audiometry when testing their hearing. Young children are not able to tell us or signal that they hear so we use toy reinforcers. With this technique the test signal is paired with a visual reward (a light up or dancing toy). Every time the child responds (turns his head toward the sound) he is rewarded for turning in the direction of the sound. With this technique we can get a good measure of hearing across the frequency spectrum.
Play Audiometry: Preschool children and some younger school age children respond better when conditioned play audiometry techniques are used when testing their hearing. The child is trained to perform an activity such as placing a block in a box each time a sound is heard. This approach is less intimidating for younger children and alleviates fears associated with the test situation.