Electrocochleography (ECOG) is a diagnostic test that examines the function of the inner ear. This test measures the electrical potentials generated in the inner ear in response to sound.
The ECOG is most often used to determine if the inner ear has an excessive amount of fluid pressure, which can cause symptoms such as hearing loss, aural fullness, dizziness, and/or tinnitus. These symptoms are sometimes indicative of certain ear pathologies such as Meniere’s disease or endolymphatic hydrops.
You are asked to refrain from wearing any base makeup on the day of your test. The forehead will be scrubbed clean and small electrodes will be taped to the skin. The ear canals will be scrubbed clean and foam electrodes will be placed in each ear canal. You will lie still with your eyes closed while listening to a series of fairly loud clicks. There will not be any discomfort during the test. Any tension or muscle movement can slow down the testing process, thus it is very important to be relaxed during this test.
A computer will record several responses from the ear. The audiologist will identify a large waveform, which directly results from providing sound stimulation to the inner ear. This waveform contains two components, the summating potential (SP) and the action potential (AP). An enlarged ratio between these two components (SP/AP ratio) can indicate excessive fluid pressure in the ear. This test takes approximately one hour.
The audiologist will analyze the results and then send the report to the referring physician.