Acoustic Reflex Testing
If you find that you have symptoms of hearing loss it is imperative to get your hearing checked right away. There are many different types of tests to check for hearing loss and it is likely that you will be ordered a series of them. Each hearing test measures different parts of your ear to check for different kinds of hearing problems. The tests that are ordered for you will be determined by a hearing care professional and depend on your specific hearing loss symptoms.
We understand that the words ‘hearing test’ can be pretty nerve-wracking when you don’t know what to expect. Which is why we have compiled resources for you to easily learn about each of the different types of hearing tests. In this particular article, we go in depth on everything you need to know about acoustic reflex testing.
What is Acoustic Reflex Testing and How Does it Work?
There is a small muscle in your middle ear that involuntarily stiffens when triggered by a loud noise. This act of stiffening is called the ‘acoustic reflex.’ The louder the sound has to be before triggering the acoustic reflex, the worse your hearing is. The reason that the acoustic reflex exists in our ears is to reduce the loudness of our own voices while we are speaking. This is because we actually hear ourselves louder than we hear others. We hear our own voices through air conduction and bone conduction sound waves, which is why we hear ourselves so differently from other people’s voices; this is also the reason that so many individuals don’t like the sound of their own voice. So basically, our acoustic reflex exists to protect us from the loudness of our own voices.
Acoustic reflex testing is a sub test of tympanometry. Meaning, one’s acoustic reflex can only be tested during a tympanometry test. Those with normal tympanograms are tested again with acoustic reflex testing to pinpoint the exact location of and type of hearing problem they have. However, while tympanometry uses different air pressures to test for eardrum functionality, acoustic reflex testing uses a fixed air pressure where sound is allowed into the eardrum. The testing devices and procedure for testing the acoustic reflex are the exact same as they are for tympanometry testing: A tympanometer probe will be placed in your ear and you will feel some air pressure in your ear canal, but the feeling should be painless. The results from an acoustic reflex test will show up as a sort of curve on the tympanogram. The goal is for the Acoustic reflex curve to be smaller than the initial curve from the normal tympanogram.
Why Test the Acoustic Reflex?
The acoustic reflex covers a lot of area in the ear, including the brainstem, inner ear, middle ear, outer ear, etc… Thus, most of the auditory pathway is tested for functionality during an acoustic reflex test. Any problem along those parts of the auditory pathway will show up in acoustic reflex testing and will help to detect the type and underlying cause of hearing loss present in a patient.
The acoustic reflex is tested during a tympanometry hearing test, using a tympanometer to measure the functionality of different parts of the auditory pathway. Your hearing care professional can determine what parts of the auditory pathways aren’t working properly based on the tympanogram results. This will help the professional to pinpoint the underlying cause and type of hearing loss you have.
Thank you for reading this article,
Senior Editor, Audien Hearing
Drew Sutton M.D.
Drew Sutton, MD is a board-certified otolaryngologist. He has extensive experience and training in sinus and respiratory diseases, ear and skull base surgery, and pulmonary disorders. He has served as a Clinical Instructor at Grady Hospital Emory University for more than 12 years.