The audiologic evaluation consists of a battery of tests, each providing specific information. Yet, the tests are complementary to one another. The audiologic evaluation consists of several different components.

Case History

The audiologist will ask several questions during the case history.

For children, questions may also be asked regarding:

• Speech and language development

• Health history

• Recognition of and response to familiar sounds

• The startle response to loud, unexpected sounds

• The presence of other disabilities

• Any previous hearing screening or testing results

Physical Examanation
The audiologist will look at the outer ear (the pinna) checking for any malformation. The audiologist will use an otoscope, an instrument that contains a light and a magnifying lens, to examine the ear canal and eardrum. The ear canal is examined for the presence of excessive wax (cerumen), or foreign objects (food, toys, pieces of cotton swabs, etc). The eardrum (tympanic membrane) is examined for any perforation or signs of fluid. The audiologist will look for any indicators suggesting the need for referral for a medical evaluation and/or treatment.

Tests of Middle Ear Function
The audiologist may also take measurements that will provide information about the status of the outer and middle ear. Tympanometry can assist in the detection of fluid in the middle ear, perforation of the eardrum, or wax blocking the ear canal.

Tests of Hearing
The audiologist will conduct tests of hearing tones via speakers or headphones. This is called pure-tone audiometry which is given to determine the faintest tones a person can hear at selected pitches (frequencies) from low to high. Pure-tone audiometry is completed in a soundproof booth. Sounds may also be sent through a special headset "vibrator" that has been placed just behind the ear or on the forehead.

The audiologist may also determine speech reception threshold or the faintest speech that can be heard half the time. The results are recorded on a graph called an audiogram.

Sometimes children are given a more "play-like" activity (conditioned play audiometry) to indicate response. They may be instructed to string a peg, drop a block in a bucket, or place a ring on a stick in response to hearing the sound. Infants and toddlers are observed for changes in their behavior such as sucking a pacifier, quieting or searching for the sound and are rewarded for the correct response by getting to watch an animated toy (visual reinforcement audiometry).

Additional specialized testing may be indicated and recommended based on the initial test results. There are a variety of other audiologic procedures that assess the auditory system and determine the presence of hearing loss. They are sometimes used independently and sometimes used to complement the standard audiologic test battery. They help to supplement information from behavioral testing or to resolve conflicting information from behavioral testing. They are auditory evoked potentials and otoacoustic emissions testing.

Auditory Evoked Potential
Auditory brainstem response (ABR) is an auditory evoked potential that originates from the auditory nerve. Electrodiagnostic test procedures give information about the status of neural pathways. These procedures are typically used with individuals who are difficult to test by conventional behavioral methods and are often used with babies. If the audiologist recommends an ABR, and a child is over the age of three months and cannot be tested during natural sleep, the audiologist may recommend sedation. Your child will have to be seen by a Children's Hospital ENT, where clearance for sedation will be determined. ABR can also be used for a person with signs, symptoms or complaints suggesting a nervous system disease or disorder. Testing consists of the recording of brain wave activity in response to sound from electrodes placed on the head (similar to the electrodes placed around the heart for an electrocardiogram.)

Otoacoustic Emissions (OAE)
Otoacoustic emissions (OAE) are inaudible sounds emitted by the cochlea when the cochlea is stimulated by a sound. When sound stimulates the cochlea, the outer hair cells vibrate. The vibration produces an inaudible sound that echoes back into the middle ear. The sound can be measured with a small probe inserted into the ear canal. Persons with normal hearing produce will elicit emissions. Those with hearing loss greater than 25-30 dB do not.

Audiologists at Children's Hospital provide all the services listed above. The Children's South audiologists provide all services excluding the ABR test. Audiological evaluation may result in recommendations for further follow-up such as medical referral, educational referral, hearing aid assessment, assessment for assistive listening devices, audiologic rehabilitation assessment, speech and language assessment and / or counseling.