Living with hearing in only one ear – known as single-sided deafness (SSD) or unilateral deafness – can greatly impact your daily life and emotional well-being. It can affect your ability to follow conversations, locate sounds, and feel connected in social settings.
Thanks to advances in hearing technology, cochlear implants are now a proven treatment option for many people with single-sided deafness. These small, surgically implanted devices can help restore hearing in the deaf ear, improving sound awareness and speech understanding.
In this blog, we’ll explore what single-sided deafness is, the challenges it can present, and how cochlear implants help restore the sensation of sound.
What is single-sided deafness?
Single-sided deafness (SSD) is a type of hearing loss where a person has little to no hearing in one ear, while the other ear functions normally or near normally. This condition can make everyday listening more difficult, especially in noisy environments or when trying to locate where sounds are coming from.
Most cases of single-sided deafness are sensorineural in nature, which means that your hearing loss is caused by damage to the hair cells in your inner ear.
Living with single-sided deafness
There are some challenges unique to single-sided deafness. These include:
- The ‘head shadow’ affect, which is the reduced ability to hear sounds originating from the deaf side. This is because your head physically blocks sound waves, especially high-frequency ones, from being heard in your working ear. As a result, sounds may sound muffled because you can’t register high-frequency sounds such as ‘s’ or ‘f’.
- Sound localisation, which is the ability to pinpoint where a sound is coming from. This is because you identify the source of a sound by which ear hears it first; this is not possible if you are deaf in one ear.
- Being unable to tell how loud a sound is. This is because your brain perceives the volume of a sound more accurately when both ears receive input.
- Disorientation in noisy environments, because your brain is less able to filter out irrelevant noises with only one ear.
What causes single-sided deafness?
There are various reasons why someone might develop single-sided deafness. This includes:
- Meniere’s disease – an inner ear condition that affects balance and hearing
- acoustic neuroma
- traumatic brain injury
- viral or bacterial infections
- physical damage to the ear
- noise-induced hearing loss
- circulatory system disorders
- genetic or inherited disorders, including neurofibromatosis type 2
Sometimes, there is no apparent cause for developing single-sided deafness.
Single-sided deafness that comes on suddenly (called sudden sensorineural hearing loss) is not normal and should be investigated and treated as an emergency. Depending on the cause and how quickly it is treated, there is a good chance of a full recovery.
Single-sided deafness symptoms
The symptoms of single-sided deafness are typically the same as that of hearing loss in both ears. This includes:
- difficulty following conversations, particularly in noisy environments
- frequently asking people to repeat themselves
- turning up the volume on your TV or mobile phone louder than usual
- difficulty hearing on the phone
- experiencing ringing in your ears (tinnitus)
- fatigue from the increased concentration required to listen
- social withdrawal and anxiety
What are cochlear implants?
A cochlear implant is an electronic device that helps to stimulate the auditory nerve, providing the sensation of sound in patients with deafness or profound hearing loss in one or both ears. They have been found to be beneficial in improving sound localisation and speech understanding in people with single-sided deafness.
Cochlear implants only work for patients with sensorineural hearing loss, which is the most common type. Sensorineural hearing loss occurs in the inner ear.
The ear is made up of three parts: outer, middle, and inner. The inner ear contains the cochlea, a small, fluid-filled structure. Sound waves cause this fluid to vibrate, triggering the hair cells (which line the cochlea) to produce electrical impulses. These impulses travel to the brain via the auditory nerve, where they are interpreted as sound.
If your hair cells are damaged, they will not be able to convert sound waves into electrical impulses. In people with mild hearing loss, hearing aids are used to amplify the sound waves so that they can be converted. This is not possible in people who are deaf or who have profound hearing loss.
How do cochlear implants work?
A cochlear implant is composed of an external and internal part. The external part of the cochlear implant (also referred to as the ‘sound processor’) is small disc-shaped device worn on the head, which picks up sounds and converts them into electrical signals.
The signals are received via the internal part of the implant, which is placed under the scalp. The internal implant converts these signals into electrical currents, which are then passed down an electrode in the cochlea to stimulate the auditory nerve. The auditory nerve sends signals to the brain, which are interpreted as sound.
How do cochlear implants work?
A cochlear implant is composed of an external and internal part. The external part of the cochlear implant (also referred to as the ‘sound processor’) is small disc-shaped device worn on the head, which picks up sounds and converts them into electrical signals.
The signals are received via the internal part of the implant, which is placed under the scalp. The internal implant converts these signals into electrical currents, which are then passed down an electrode in the cochlea to stimulate the auditory nerve. The auditory nerve sends signals to the brain, which are interpreted as sound.
Benefits of cochlear implants for single-sided deafness
The benefits of cochlear implants for single-sided deafness include:
- enhanced speech understanding, particularly in noisy environments
- improved sound localisation, allowing patients to better determine where sounds are coming from
- reduction in tinnitus, with some patients experiencing a significant reduction in, or even the complete elimination of, this symptom
- improved quality of life, with patients experiencing better social interactions, reduced listening effort, and increased confidence
- restoration of binaural hearing (hearing in both ears), allowing for a more natural and balanced hearing experience
Cochlear implants at Cromwell Hospital
The cochlear implant programme at Cromwell Hospital is available for adult patients with unilateral or bilateral sensorineural hearing loss.
The programme includes:
- a comprehensive initial assessment, with hearing tests (audiometry), speech tests, balance tests, and videonystagmography (a test that evaluates your eye movements)
- the surgical implantation of your cochlear implant(s), performed by leading ENT surgeon Mr David Selvadurai
- a 12-month follow-up package with an audiologist, to help calibrate your device and track your progress
If you are paying for yourself, please contact our dedicated Self-Pay team on 020 7244 4886.
If you are intending on using private medical insurance, please check with your insurer that this is covered before booking an appointment.
For more information about the programme and surgical procedure, please visit our dedicated webpage.
