Quick Read
There are several kinds of hearing tests your audiologist may try, including having you sit in a soundproof area (or wear headphones) indicating whether you can hear certain tones or words, or slightly changing the pressure in your ear to see if your ear drum moves properly. None of these tests should hurt.
First and most importantly, a hearing test should never hurt. The audiologist may try several different methods in order to get the fullest picture of the degree and causes of any hearing loss, and some of these may seem a little bizarre, such as placing a vibrating probe on the bone behind the ear or changing the pressure in your ear (more on those below), but none of these should be painful. Second, if you want to understand why the doctor is performing the tests they are, you need to understand the process by which we hear. You can read a quick summary of that here.
The first thing the audiologist will probably do is physically look into the ear canal with an otoscope. This is to check for any abnormalities or obstructions that could be causing hearing loss. Even build ups of ear wax can cause significant difficulties with hearing, so checking this first can rule out a lot of simpler problems that might be responsible.
After the visual check, there are a number of tests that the audiologist may perform to evaluate your hearing:
Pure Tone Auditory (PTA): This is one of the most common hearing tests. You will be asked to sit in a soundproof room or booth wearing headphones, and the audiologist will use a machine called an audiometer to determine the volume level you require to hear a number of different pitches. Each ear will be tested separately, and you will hear a series of tones getting louder and quieter as the doctor adjusts the volume. You will be asked to push a button or raise your hand every time you hear a tone, even if it sounds very quiet.
Speech Perception and Word Recognition: A series of words will be played through headphones or speakers, or spoken by the audiologist, who may also introduce a measured level of background noise. You will be asked to repeat the words spoken to you. The audiologist may look at how well you understand speech in different situations, including speech at normal conversational levels, amplified speech, and speech in background noise.
Tynpanometry: A device is used to seal one ear closed with a bit of plastic, and then to change the pressure in your ear canal. What the audiologist is doing is measuring how much the eardrum moves in response to the pressure. This test can determine if there is something keeping the eardrum from moving properly, such has fluid behind the ear, excess wax, or other potential problems.
Tuning Fork Test: A tuning fork is a piece of metal which branches into two prongs (kind of like a large dinner fork with only two tines). When tapped on a hard surface, it produces a specific tone. The audiologist may do this, and then hold the tuning fork at various places around your head to see if you can hear it. Like the Bone Conduction Test below, this often helps in determining the specific type of hearing loss.
Bone Conduction Test: This test is often used in conjunction with PTA, in order to determine whether hearing loss is caused by problems with the ear canal, eardrum, or hearing bones, or whether it has a sensory or neurological cause. A vibrating tool called a bone oscillator is placed on the bone directly behind your ear, and transmits tones directly through the vibration.