By Brian Urban
As the sound makes its way inside of the ear canal, it ends up vibrating the tympanic membrane, which is also known as the eardrum. Your eardrum is essentially a very fine piece of skin, which is less than a half of an inch wide. It is located in between the middle ear and the ear canal.
The Eustachian tube connects the middle ear into the throat. Due to the amount of air from within the atmosphere, your outer ear and the air pressure upon both of your eardrums will remain consistent. It is because of this balance that your eardrums are able to move back and forth with ease.
The eardrums are extremely sensitive and rigid. Even the smallest of fluctuations in air pressure will cause it to move back and forth. It is connected to the tensor tympani muscle, which is constantly working to pull it inside. This action helps to keep the whole membrane tight so that it will vibrate, regardless of what direction the sound wave is coming from.
This miniscule piece of skin acts identical to that of the diaphragm within a microphone. The drum is pushed back and forth because of the rarefactions and the compressions of the different sound waves. Louder sounds cause the eardrum to move at an increased distance, while the higher pitched sounds cause it to move at an increased rate of speed.
Your eardrum also works to protect your inner ear from being exposed to any loud and low pitched sounds. Whenever the brain receives any signals for noises, the eardrum will have some form of a reflex. The stapedius and tensor tympani muscles will end up contracting all of a sudden.
Due to the contractions, the eardrum will end up pulling the bones within the ear in opposite directions, which causes the eardrum to become more rigid in nature. Whenever this occurs, the ear will not receive the level of noise needed at the lower end of the speech spectrum, which causes the loud noises to be lowered in sound.
Beyond just protecting your ear, this reflex ends up helping you to concentrate on your hearing. It helps to mask out the loud noises in the background to allow you to focus your attention on the higher pitched sounds. Amongst other factors, this also helps you to carry on a conversation whenever you are in an extremely noisy environment, such as a rock concert or an auditorium.
The reflex also jumps into motion to help you hear when you begin talking. Otherwise, you would only end up hearing the sound of your own voice and it would cancel out anyone else who may be talking around you.
The eardrum is essentially the main element for sensing sounds in your entire ear. All of the other components of your ear only work to pass the information along that have already been compiled at the eardrum. As complex as the hearing process is, this is only a portion of it and there is a lot more that goes into allowing us to hear the sounds in the environment on a regular basis.
Brian Urban, Au.D., a Board Certified Doctor of Audiology, is the owner of Advanced Hearing and Balance Center (formerly Communication Care Center) in Evanston, Illinois promise to work closely with you to discover where you are having the most difficulty communicating. Call today at (847) 453-3643 to make appointment or for up-to-date hearing aid information visit Dr. Urban’s blog.