First of all, we need to understand what the audiologist will be looking for. The audiologist will most likely test your hearing in a number of different ways, to determine where the hearing problem is located. At the end of your hearing test, the audiologist should explain the tests he or she performed and interpret the results.
Before proceeding, your audiologist will ask you a few questions about your medical history. He or she will want to know about noise that you have been exposed to at or outside of work. As well, he or she will need to know if any physical damage has ever occurred to your ears. You may also be asked questions about past illnesses and any other basic medical history that may have had an impact on your hearing, i.e. medications, etc. This helps the audiologist decide the best way to assist you with your hearing loss.
Looking into your ear
At the beginning of your hearing exam, the audiologist will probably look into your ears with an instrument that is cone-shaped and has a light in one end. What is that all about? Well, this device is called an Otoscope. It helps the audiologist to see into your ear better and determine if there are any abnormalities in the ear canal or eardrum.
The sound booth / room The next step is for the audiologist to place you in a quiet sound room. No you won't be recording any hit songs or mixing soundtracks in here. This room will ensure outside noises will not interfere with test results.
The pure tone tests
Next, your audiologist will conduct pure tone tests. You will be asked to place, either a set of headphones over your ears or, to insert a small set of earplugs into your ears.The headphones or inserted plugs will deliver a series tones into your ears. A device called an audiometer electronically generates these "pure tones" which vary in tone and volume. This test helps the audiologist to determine the threshold at which a patient hears different frequencies. Each ear is tested individually. You will indicate when you hear a tone by raising your hand or pushing a button.
Next, the audiologist will put a small bone conductor behind you ear and with this device, he or she will test the pure tones again. The bone conductor transmits sound through bone vibration, to the cochlea of the inner ear, bypassing the middle and outer ear. It helps the audiologist determine the type of hearing loss in the patient.
The next step is the Speech test. Like the pure tone test, you will be seated in a sound isolated room, and the audiologist will most likely be in an adjacent room. You will then hear a series of words that you will be instructed to repeat. Some of the words will be two syllables and will become softer as you go along. A second set of one syllable words will be produced. The volume of these will stay the same. This test allows the audiologist to determine the level at which the patient can detect and understand speech (not merely that speech is present.)
Test of the Middle ear
The audiologist may also check the middle ear with an impedance test. A probe is placed in your ear and air pressure is increased and then decreased while a tone is presented. A graph will be generated with the results of the test.
Depending on the test results, there may be other hearing tests performed. The audiologist will then take the whole pile of graphs, papers and reports and explain what they mean.
The results of these hearing tests are recorded in a chart called an audiogram. An audiogram is a graph with red O's and blue X's connected with little lines. The O's represent the right ear and the X's indicate the left. Marks near the top of the graph are an indication of better hearing while marks further down the graph denote worse hearing. Located across the top or bottom of the audiogram are frequency numbers ranging from 125 Hz, a very low tone, to 8000 Hz, a very high tone.
Along the side the graph a series of decibel (dB) numbers indicate loudness. Very soft sounds are at the top (-10 or 0 dB) and loud sounds (110 db) are located at the bottom. Zero dB does not mean that there is no sound. This level is merely the softest sound a person with normal hearing ability can perceive 50% of the time. A normal conversation usually occurs at about 45 dB on the decibel scale.
Looking at your audiogram you can tell which ear you hear better in, as well as how mild or severe your hearing loss is. You can also determine the frequencies at which you hear best and worst. The word tests will indicate test reliability and/or where in the hearing system you may have problems.
We will take the time to explain your test results. Remember, there are no stupid questions. If you have any questions, or don't understand something, just ask. It is your hearing and you have a right to know.