Electrodiagnostic test procedures give information about the status of neural pathways. These procedures are used with individuals who are difficult to test by conventional behavioral methods. They are also indicated for a person with signs, symptoms or complaints suggesting a nervous system disease or disorder.
Auditory brainstem response (ABR) is an auditory evoked potential that originates from the auditory nerve. It is often used with babies/young children. Electrodes are placed on the head (similar to electrodes placed around the heart when an electrocardiogram is run), and brain wave activity in response to sound is recorded.
Sohmer and Feinmesser were the first to use this method in 1967. Jewett and Wiliston followed in 1971. They gave a better description of the method. Auditory Brainstem Response is a good way to test people woth hearing problems in order to give them the best hearing aid as possible. There are some advantages and disadvantages of using this test for hearing aids fitting. The advantages are: determination of basic hearing aid properties (gain, compression factor, compression onset level); cases with middle ear impairment (contrary to acoustic reflex methods); non-cooperative subjects even in sleep; sedation or anesthesia without influence of age and vigilance (contrary to cortical evoked responses). The disadvantages are: in cases of severe hearing impairment including no or only poor information as to loudness perception; no control of compression setting;no frequency-specific compensation of hearing impairment.
