Single-Sided Deafness: What It Is and How to Treat it

Originally Published February 26, 2020

Experiencing hearing loss is difficult. 

In group conversations or at events with a lot of background noise, it can be incredibly challenging to understand what people are saying. 

Sitting next to friends and family and asking them to talk into your ‘good ear’ is often necessary to participate in conversations. Sometimes sounds can’t be heard at all from your deaf side which can be incredibly frustrating. Figuring out where sounds are coming from is also nearly impossible. Our brains need equal sound from both ears to localize where sounds are coming from. 

If any of this sounds familiar, you may find your physician diagnosing you with single-sided deafness (SSD).

There is no cure for SSD, but don’t lose hope - there are ways you can treat it so you can hear again on your deaf side.

Before we discuss how to treat your SSD, let's talk about what it is and what causes it.

What Is Single-Sided Deafness?

Single-Sided Deafness (SSD) is the significant or total loss of hearing in one ear. This type of hearing loss is usually permanent.

It can occur at any time during your life and sometimes even overnight. In most cases, it’s caused by unknown reasons, but it can also be due to:

• Physical damage to the ear
• Viral or bacterial infections in the inner ear
• Tumors located in the ear or brain
• Severe Meniere’s disease 
• Head trauma
• Diseases like measles, mumps, or meningitis
  

When treating single-sided deafness, it’s important for your audiologist to discuss the cause of the deafness and more importantly how long the deafness has been there. 

In other words, how long has the ear and the brain on that side been deprived of sound?

Our brains are designed to hear equally on both sides as we need equal sound on both sides in order to figure out where sounds are coming from. 

This is important when it comes to background noise. If your brain knows where sounds are coming from, then it can easily filter out background noise and let you focus on hearing the person in front of you. 

If you have one good ear and one deaf ear, your brain won’t know where the background noises are coming from. This is incredibly distracting for your brain making it harder for you to understand the noise in your environment. 

What Problems Does Single-Sided Deafness Cause?

Being deaf in one ear can cause many problems and challenges in your day-to-day life. One of the most difficult challenges you’ll have to overcome is figuring out which direction certain sounds are coming from. An issue that hinders this is the so-called “head shadow effect.”

The “head shadow effect” prevents you from picking up the sound of consonants from your deaf side. They have a shorter wavelength and unlike vowel sounds (which have a much longer wavelength), they can’t travel from the deaf side to the hearing side. 

Consonants carry the most meaning in speech, which can make it frustrating when trying to communicate with people - especially in an area with a significant amount of background noise. 

Although it may be difficult to localize sound in an area full of background noise, using sound localization or directionality is a very important aspect of managing your SSD. Localizing sound will help you communicate better and be safer overall in your daily life.

When you can’t hear from one side, things that would often seem mundane and basic to other people, like crossing the street or going for a jog, become quite difficult and at times, dangerous. 

You may find yourself in a difficult communication situation when you’re:

• Communicating in a large group, as it can be hard to hear people over the sound of other people talking 
• Whispers in quiet environments into your deaf ear can be very difficult to pick up
• Communicating while in a car if your deaf ear is facing the driver

The above situations and many more like it can affect your daily activities. You might find yourself easily irritated or become a lot jumpier than before. If you have SSD, it's also common to develop stress headaches from a feeling of isolation and constant communication difficulties. 

Take eating at a restaurant with friends, for example. Watch as the subject is presented with the same situation, but in the second example with their deaf ear towards the person talking to them:

How To Treat Single-Sided Deafness

The deaf ear receives no clinical benefit from amplification in SSD cases. So, no matter how loud a hearing aid makes the sound, the speech will never be clear or understandable in that ear. The other ear usually has a normal hearing ability, but sometimes this isn’t the case. 

The only way to completely restore binaural hearing (hearing on both sides) is with a cochlear implant. Although, if a patient doesn't want to undergo cochlear implant surgery or the subsequent auditory training period, there are other treatments that will help return the sensation of hearing on their bad side, by sending those sounds into the good ear. 

The most common treatments used for SSD are BAHA (bone-anchored hearing aid) or the CROS (contralateral routing of signal) and BiCROS (bilateral contralateral routing of signal) hearing aid systems.

Let's take a closer look at the three ways to treat single-sided deafness. 

1. Cochlear Implants

Cochlear implants are the gold standard and the best way to treat SSD. It’s the only way sound can stimulate that side of the brain again and therefore the only way that localization and better hearing in noise can occur. 

When deciding if a cochlear implant is appropriate for you your audiologist needs to address how long that side of the brain and the auditory nerve have been deprived of sound. The less time the ear has been deaf, the better. 

2. CROS

CROS stands for Contralateral Routing Of The Signal. These look like a pair of hearing aids - a hearing aid for the good ear and a microphone transmitter for the deaf ear. The transmitter picks up sounds on one side of the head and sends them to the good ear. 

Most people find CROS hearing aids to be very beneficial. These hearing aids help people pick up sounds on their bad side making it easier to hear with background noise.  

At certain times though, a CROS can cause more issues than help. For example, when there is only noise on the bad side, that noise is picked up by the CROS and transmitted directly into the good ear, making it harder to understand speech. 

The CROS can be programmed to switch off during these encounters but many people just take it out.

3. BAHA

BAHA or Bone-Anchored Hearing Aid is a type of hearing aid that requires surgery. The surgery involves getting a metal implant in the bone behind your ear. The BAHA has an external processor with microphones that picks up sounds on the non-hearing side and sends the information to the good cochlea via bone conductions - vibrations of the skull.

Before deciding to have a bone-anchored hearing aid implanted through surgery we always recommend trying a CROS hearing aid first. CROS hearing aids and bone conduction hearing aids usually have about the same outcome and benefits, but with a CROS device- surgery isn’t needed. 

What’s The Difference Between CROS and BiCROS?

The CROS hearing aid system is usually worn by people who suffer from SSD. It involves a transmitter that is worn on and picks up sounds from the deaf ear and then sends it to the receiver, which is worn in the hearing ear. 

The BiCROS hearing aid system is usually worn by people who suffer from hearing loss in both ears, but one ear is deaf and the other is aidable. 

In cases like this, the transmitter is worn on the person’s deaf ear. The transmitter then picks up the sound from the deaf ear and sends it to the receiver that is worn on the ear that can hear better. The better-hearing ear does still have a loss of hearing, but the amplification provided helps the ear to pick up the information coming from the deaf ear. 

If you’re concerned about your hearing in one or both ears or think you might need a hearing aid, get your hearing tested. We are available to help you with any implantable or non-implantable solutions for your SSD. Schedule an appointment by calling us at (916) 646-2471 or click here.