Single-sided deafness (SSD), also known as unilateral deafness, is a type of hearing loss where the person has normal hearing in one ear but significant hearing loss, or no hearing at all, in the other ear.
Common causes of single-sided deafness in adults include acoustic neuroma, sudden idiopathic hearing loss, exposure to sudden impact noise, head trauma/traumatic brain injury (TBI), and Meniere's disease.
Acoustic Neuroma: A slow growing, noncancerous tumor that develops on the main nerve that connects the inner ear to the brain. The nerve has two branches. One branch influences balance and the other transmits hearing. Some of the symptoms of an acoustic neuroma include hearing loss in one ear accompanied by ear fullness and ringing noises (tinnitus) in the same ear, unsteadiness, facial numbness, and mental confusion. As the tumor grows it can become life-threatening. Treatment to remove the tumor often results in SSD.
Sudden idiopathic hearing loss: Usually caused by a viral infection, although sometimes the cause is unknown. The virus normally infects the cochlea causing localized swelling, resulting in sudden permanent damage to the inner structures of the cochlea. The patient is normally left without any hearing in one ear.
Exposure to sudden impact noise: Noise exposure remains a huge public health problem. However, exposure to a high level of sudden impact noise, without noise protection, is detrimental to good hearing. For example, just a single shot from a large caliber gun at close range, or from a loud explosion closer to one ear, can cause SSD. The most common signs of possible hearing loss due to sudden impact noise exposure are tinnitus accompanied by immediate hearing loss.
Head trauma/traumatic brain injury (TBI): Blunt trauma to the head or the occurrence of unilateral vascular insults might result in damage to the temporal bone, the vascular structures in the brainstem, or to the cochlea damaging the auditory pathway causing SSD.
Meniere's disease: Meniere's disease occurs when excess fluid pressure in the ear produces long-term damage to the cochlea. Symptoms of Meniere's disease typically occurs on one side only and include a roaring tinnitus, a feeling of ear pressure or pain, hearing loss that comes and goes, and severe vertigo.
Effects of single-sided deafness in adults
Localization and spatial hearing: There are specific cues in our two-ear input auditory system that allows us to orient and localize sound. If there is damage to the hearing in one ear, confusion relating to spatial orientation and the direction the sound is coming from will occur. Persons with SSD may often respond to sound or speech by turning in the opposite direction from where the sound source originated.
Head-shadow effect: Occurs when speech presented at the poor ear is forced to cross over the head to the opposite side so that it can be heard by the good ear. The head-shadow effect causes persons with SSD to have difficulty understanding speech when background noise is present, creating significant communication problems for them in places like restaurants, bars, or at a party, etc.
Binaural summation: There is a saying, two ears are better than one, and we see this played out in binaural summation. Binaural summation is the auditory boost we receive when both ears are functioning properly and hear sounds equally well. Binaural summation results in easer listening and an improvement in word recognition. Persons with SSD may frequently misunderstand what is said, particularly soft-spoken speech. They also tend to tire more easily as so much effort is exerted with trying to listen all day.
Communicating with a person who has SSD
The following tips can help improve your ability to communicate with someone who has single-sided deafness:
o Always speak closest to the better ear.
o Avoid places that are noisy; find a quiet spot when in restaurants, etc.
o Always face the person with SSD. If they cannot see you, they probably cannot hear you well.
o Avoid speaking to them from another room.
o Do not turn your back or walk away while speaking.
o Always speak clearly. Avoid mumbling or whispering. Practice speaking in a normal, clear voice.
o Avoid dark places or mood lighting. The person with SSD will understand you much better in a well-lit environment where they can see your facial expressions, lip movements, and body gestures.
o Reduce or eliminate background noise like TVs, radios, fans, and air-conditioning as these can drown out the conversation.
o When communicating with a person with SSD in a car, arrange seating, if possible, so that their good ear is nearer to you. Keep the radio/music turned off to help them hear you better. Remember, even engine noise and noisy traffic can make it difficult for them to follow the conversation.
o Avoid putting your hands over your mouth, smoking, and chewing when speaking to a person with SSD. Your face and lips should always be visible to the person with a hearing loss as it gives them crucial clues regarding what is being said.
o Keep moustaches and beards trimmed as they hide the lips making it difficult for a person with SSD to follow a conversation.
Hearing aid help for unilateral hearing loss
In addition to the above communication tips, a person with SSD may also receive significant help communicating by using one of the hearing devices mentioned below.
CROS hearing aid: - A CROS hearing aid is specifically designed for persons with single-sided deafness. A microphone that resembles a hearing aid is placed on the dead ear. The acoustic signal picked up by the microphone is then routed to an amplifier that is placed on the good ear. The sound that is heard at the dead ear is then contralaterally sent over to the good ear, allowing the person with SSD to have the perception of "hearing" on the poorer side.
Bone-anchored hearing aid (BAHA): A Bone-anchored hearing aid is another device option for persons with SSD. The BAHA is a surgically implanted hearing system that works by directly transferring sounds through bone vibration to the cochlea, bypassing the outer and middle ear.
Single-sided deafness affects not only listening and communicating, but also quality of life. If you or someone you know is suffering from single-sided deafness, or if you have concerns regarding your hearing and would like a hearing evaluation or a hearing aid, contact an audiologist.

o For further information on any hearing-related disorder, please contact Dr. Deborah Nubirth, doctor of audiology, in New Providence at Comprehensive Family Medical Clinic, Poinciana Drive at 356-2276 or 677-6627 or 351-7902 in Grand Bahama; or email dnubirth@yahoo.com.

Click here to read more at The Nassau Guardian