Unilateral hearing loss, or hearing loss in only one ear, is one form of hearing loss that people may experience at any time across the lifespan. While people with unilateral hearing loss may appear to function as if they do not have hearing loss in many situations, there are several instances in which their hearing loss will cause them to struggle. If you want to learn more about unilateral hearing loss and its impact, you’re in the right place!
Unilateral hearing loss is defined as a diagnosis of hearing loss in one ear only, while the other ear has normal hearing sensitivity. The degree of hearing loss in the poorer-hearing ear can range greatly, from mild hearing loss all the way to profound hearing loss. Many people with unilateral hearing loss can appear to pass for having normal hearing, especially in quiet environments, because their one ear with normal hearing sensitivity is capable of processing all of the input in order to hear and understand sounds around them. However, in noisier environments or situations in which the sound quality is poorer, the person with unilateral hearing loss may struggle to hear and understand. In these situations, having only one ear with normal hearing may not be enough to provide the person with all of the information needed to properly process and understand the sounds in their environment.
What is single-sided deafness?
Single-sided deafness occurs when a person has no usable hearing in one ear, but has normal hearing or hearing loss that can be fit with a hearing aid in the other ear.
How common is unilateral hearing loss?
Around 7% of adults living in the United States have some degree of hearing loss in one ear only, and around 1 in 1000 babies is born with unilateral hearing loss.
Signs of Unilateral Hearing Loss
One indication of unilateral hearing loss is having difficulty localizing, or identifying the location of, a sound in the environment. This is because the brain needs signals from both ears in order to analyze the incoming sound waves to figure out where a sound originated from. With unilateral hearing loss, this binaural hearing, or hearing in two ears, is disrupted, making it difficult or impossible for the brain to pinpoint the source of a sound. Without these cues from both ears, people with unilateral hearing loss will notice that they are unable to quickly and accurately locate, for example, the position of a person calling their name from behind them.
Another sign of unilateral hearing loss is difficulty hearing in noisy situations. When both ears have normal hearing, the brain can use the input from both sides to unconsciously filter out the background noise so that less attention is given to the background than the speech the person actually wants to listen to. When unilateral hearing loss is factored in, the brain is receiving a much more prominent sound input from the normal-hearing ear, making it unable to accurately filter the speech from the background noise. Hence, people with unilateral hearing loss will often struggle to understand speech in more difficult listening environments such as a loud party or an exhibit hall at a conference. This may lead to misunderstandings, asking for more repetition, or the person with unilateral hearing loss withdrawing from the situation.
What should I do if I think I have unilateral hearing loss or single-sided deafness?
If you think you have unilateral hearing loss or single-sided deafness, you should make an appointment to see an audiologist and an otolaryngologist (a physician who specializes in the ear, nose, and throat). The audiologist will perform tests to determine the degree and nature of your hearing loss. This information can help ascertain potential audiological management options. The otolaryngologist will undertake a medical evaluation in order to assess the cause of the hearing loss and decide what further testing may be needed. These assessments are important for deciding whether any medical treatments related to the hearing loss should be pursued prior to beginning audiologic management.
Why is it important to manage unilateral hearing loss or single-sided deafness?
Management of unilateral hearing loss and single-sided deafness allows for better access to all of the sounds around you. Having better awareness of sounds in the environment can help you stay safer by giving cues as to what is going on nearby. For instance, someone with unilateral hearing loss may not be able to know that a car is coming from one side while they are waiting to cross the street because they will be unable to hear the noise of the car until it is very close by.
When unilateral hearing loss and single-sided deafness are managed, there can also be a social benefit. With management, a person with unilateral hearing loss or single-sided deafness may be able to hear and understand more clearly in situations where the noise level is higher. An improvement to hearing in noise can boost the confidence of the person with unilateral hearing loss and give them the motivation to stay in a noisy situation for a longer period of time without withdrawing. Being capable of staying in social situations for an extended period of time can help the person feel less lonely and more connected to the people around them.
Additionally, an asymmetry in hearing between the ears can sometimes be an indication of a medical condition that is impacting one ear and not the other. It is essential that the management of unilateral hearing loss and single-sided deafness includes a medical evaluation to determine whether a specific cause for the hearing asymmetry can be found.
How is unilateral hearing loss managed?
There are many technological options for people with unilateral hearing loss. The degree of hearing loss, reason behind the hearing loss, and other health factors in a person’s life can help determine the best management option for each specific situation.
With more mild degrees of unilateral hearing loss, a traditional hearing instrument on the poorer-hearing ear can be an appropriate solution. The hearing instrument amplification will be programmed according to the poorer ear’s hearing loss, allowing for better access to sound on that side and assisting in helping the user feel as though their hearing is more balanced between their two ears.
If the poorer-hearing ear has hearing loss at the severe-to-profound level, a traditional hearing instrument may not be able to provide enough amplification to be useful. In this case, one management option is a CROS hearing instrument system. In this system, the user wears a device on each ear. The device on the poorer ear has a tiny microphone that picks up sound from that side of the user’s head, then wirelessly sends the sound to the speaker of the device on the normal-hearing ear. With this system, the patient has access to sounds all around them, but all of the sounds are processed by the normal-hearing ear.
Another device that can be used when one ear has severe-to-profound hearing loss is a bone-anchored hearing device. These devices also send sounds originating from the side of the poorer ear to be processed by the better ear, but the sounds are sent through the bones of a person’s skull in a process called bone conduction. A small device is surgically implanted into the side of the head in order to utilize bone conduction.
In certain cases, some people with severe-to-profound unilateral hearing loss are also candidates for a cochlear implant. This device allows the poorer ear to be stimulated with electric signals to be sent up to the brain for processing. Since these electronic signals are sent right up to the brain, a cochlear implant allows processing of sounds and speech directly from the poorer ear’s side rather than being processed by the better-hearing ear.
How can I prevent unilateral hearing loss or single-sided deafness?
One way to prevent single-sided deafness or unilateral hearing loss is to protect your ears from loud noise. Sounds louder than 85 decibels (around the volume of a blender) can be harmful to your ears. If one ear is consistently closer to a loud noise than the other (for instance, when standing with one ear next to a speaker at a concert or driving a truck where one ear is always closer to the noise of the road), it could lead to hearing loss in the ear with the more significant noise exposure. When in noisy situations, it is important to wear hearing protection such as well-fitting earplugs to prevent damage to your hearing. And remember to give your ears a break from the noise by not staying too long in a loud environment and spending time in a quiet environment before going back into the noisy area.
What is the prognosis (outlook) for people who have unilateral hearing loss?
With the proper management strategies, people with unilateral hearing loss can be very successful. Utilization of hearing technology can play a beneficial role in awareness of sounds originating from the side of the user’s poorer hearing ear. This can help with hearing in social situations where a conversation partner is on the side of the poorer ear. Increased sound awareness from hearing technology also assists with hearing environmental sounds, such as a bicycle rider passing by on the sidewalk. Knowing that these sounds are occurring can improve safety and environmental awareness.
However, it should be noted that for people with single-sided deafness, most technology management options do not restore the ability to identify where a sound originated. Accurate localization requires the brain to process signals from two ears. As discussed above, many options for single-sided deafness continue to rely on the better-hearing ear to send all incoming signals to the brain for processing.