Unilateral Hearing Loss

While the majority of people with hearing loss have hearing loss in both ears, there are some people who have hearing loss just on one side. This is what we refer to as unilateral hearing loss. There are many causes of unilateral hearing loss; the severity and/or cause of the loss dictate how we treat it.


How do you know if you have unilateral hearing loss?  Well, most people notice that their hearing is significantly poorer in one ear than the other.  You may notice that you cannot hear conversations on a certain side, have a lot of difficulty hearing in noisy situations or crowds, or have difficulty telling what direction sounds or coming from, which we call “localization”.  You also may notice that things sound drastically different from one ear to the other, the quality of sound can vary.  You may even have some physical problems with balance.

When you go to your hearing healthcare provider to have a hearing test, he or she will be testing both of your ears.  There will also be a thorough case history taken, and the provider may ask you a number of questions, such as (but not limited to):

  • Do you notice that the right ear or left ear is better, or do they sound about the same?
  • Have you been exposed to extremely loud sounds?
  • Have you had any head injuries or been in any accidents that have affected your ears?
  • Do you have a history of middle ear problems or ear infections?  If so, which ear?
  • Have you had any time of ear surgery?  If so, which ear?  What kind of surgery?  When?  What was the result?
  • Have you seen an ENT (otolaryngologist) about any of these issues?
  • Does hearing loss run in your family?

If, when the provider does your test, he or she finds a significant difference between your ears, you will be referred to an ENT.  The law requires this, as some types of unilateral hearing loss can be signs of serious medical conditions, like acoustic neuromas (a type of tumor on the VIIIth nerve).


Now that I’ve scared the daylights out of you by suggesting the possibility of a brain tumor, I am going to tell you that there are many different causes of unilateral hearing loss:

  • Excessive noise exposure on one side, like being next to an explosion or a gun when it fires
  • Genetics/family history of hearing loss
  • Birth defects
  • Trauma to the ear or to the skull/head around the ear
  • Diseases or infections, like measles, mumps, Meniere’s disease, or sudden hearing loss
  • Chronic middle ear problems or infections
  • Acoustic neuromas

How is unilateral hearing loss treated?  Sometimes a standard hearing aid is recommended (after you have been cleared by your ENT doctor, of course).  Other times, a specialty hearing called a CROS hearing aid is recommended instead.  CROS stands for Contralateral Routing of Sound.  A CROS hearing aid works by having a microphone on the poorer ear that wirelessly sends information to a receiver worn on the better ear.  Another option for those who have middle ear problems, birth defects, or unilateral hearing loss caused by structural anomalies is a BAHA.  A BAHA is a bone anchored hearing aid that transmits sound to the cochlea through the skull.  The bones of the skull carry vibrations that bypass the outer and middle ear.


The abutment, which is surgically implanted into the skull and attached to a titanium screw, and the processor which snaps right onto it.

If you are one of the many people suffering from unilateral hearing loss, do not despair!  There are options for you.  The best course of action is to see a hearing healthcare professional for a new test as soon as possible and they will be able to guide you into the right direction.


Until next time,


Dr. Kristin