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Living with SSD: ATestimonial
It was the early 1940s and I was in elementary school when I developed the measles. I ran a very high temperature, but the doctors could not get my temperature to come down. I was supposed to swallow aspirin, but I could not do it. I remember being sick over and over trying to swallow that aspirin. All I could do was survive. My temperature stayed up for seven or eight days. When I finally began feeling better, I noticed I could not hear as well out of my left ear.
I kept asking my teacher to let me sit at the front of the classroom. During those days, no one asked to check my hearing; mostly they just stared at me as if I was stupid. I started to read lips on my own, but when the teacher turned her head I could not understand her. I asked my neighbors what she said, but they acted like I was bothering them. This went on all through school and my lip reading became better. I learned to listen carefully to what people said.
My hearing has been a problem all my life. At first, my right ear was completely normal, but over the past decade, it too has slowly begun to decrease my ability to hear high-pitch sounds. I have always wanted to hear like everyone else can hear, but I wasn't able to do this until my granddaughter gave me a hearing aid. Unfortunately, I have gone so long without out a hearing aid, I have learned to get by without taking advantage of the help. I should be wearing it all the time, but much to my regret, I still ask what people have said, particularly the people on TV. Although it aggravates my family, they still, very nicely, repeat it for me. My hearing aid is very comfortable and I am trying to use it more so I don't have to ask people to repeat everything for me.
The hardest thing in dealing with this type of hearing loss is watching television, I think. Before my granddaughter helped me hear better with these hearing aids, I wished the actors and actresses would all face me when they speak! -- Coach Wanda Bender
Treating SSD: The Other Side 
As a busy audiologist in a growing field, I find it is sometimes easier to fit the typical loss with the latest, greatest technology and the software with which I am most comfortable and has the fastest first-fit options. Recently, I have seen more atypical hearing loss responses, particularly since I work with government services clinics. It seems like asymmetrical losses are on a rise as I hear about many soldiers who are experiencing this type of hearing loss upon returning home from Iraq or Afghanistan. At the Association of VA Audiologists (AVAA) meeting in 2007, hearing loss and tinnitus were reported as the No. 1 complaints by those returning home from the war zone.
Back to Basics: What is SSD?
Single-sided deafness (SSD) refers to a significant hearing loss in one ear. The better hearing ear can have completely normal hearing or some degree of hearing loss. If there is a 15dB difference between ears, most audiologists refer to this as an asymmetrical hearing loss. If the patient's poorer hearing ear is severe to profound or has no response across frequencies, then you may refer to the loss as SSD. If the patient suspects this or a basis screening elicits either of these responses, it is imperative that a full comprehensive or complete hearing loss evaluation be performed to ensure there are no medically treatable conditions associated with the loss.
The complete audiometric evaluation should be performed sooner rather than later to be safe. Results showing SSD may indicate serious medical conditions, such as an acoustic neuroma, a slow-growing benign tumor on the auditory nerve. Other causes of SSD include Meniere's disease, meningitis or other viral infections and traumatic brain injuries. Many injuries coming out of the conflicts in Iraq and Afghanistan are caused by improvised explosive devices (IEDs). Additionally, in combat situations, there is no time to use hearing protection when firing a weapon. When hunters or, in this case, soldiers shoot a gun, the resulting hearing loss often is worse on one side.
Signs and Symptoms
SSD affects individuals of all ages. Its symptoms can result in debilitating problems in both work and social environments. Most commonly, individuals suffering from SSD have difficulty localizing sounds. Also, separation of background noise from a speech signal is very difficult since all information, both noise and speech, enters the same ear. The inability to understand speech in the presence of background noise can be painfully embarrassing. The embarrassment or frustration of SSD can negatively affect a person's emotional wellbeing.
The inability to localize the direction of a sound also can be dangerous. Take for instance, a police officer that is directing traffic. In this situation, a police officer's life may be threatened by SSD. In less serious situations, such as sitting in a movie theater, a person suffering from SSD would have to insist on seating with his or her "good ear" toward the target sounds. There may not be a seat available to accommodate this need. Talking on a cell phone can be another problematic situation. A person suffering from SSD might be able to hear from the better hearing ear over the phone but would not be able to hear any other speech in the surrounding listening environment. Patients who suffer from SSD report a desire to hear sounds from all directions and want to hear better when background noise is present. Luckily, treatment is available.
Diagnostics
Even though there are an estimated 60,000 people diagnosed each year with SSD, it is often missed in basic hearing screenings. At times, patients may report that they have a "good ear." This is largely due to the better hearing ear promoting normal speech and language development. The better hearing ear also does a relatively good job of understanding speech in many one-on-one environments or in small group conversations where background noise is minimal.
In order to determine the reason and severity of the hearing loss, a complete, comprehensive evaluation of both ears should be conducted. This should include tympanometry and middle ear integrity testing, hearing sensitivity thresholds using both bone and air conduction in the masked condition, and performance-intensity functions for phonetically balanced word (PI-PB) screening, or some form of retro-cochlear audiometric measure. Remember to follow masking rules for placing noise in the better hearing ear to assure the results obtained are true and valid for the poorer hearing ear. Word discrimination scores also should be obtained in the masked and unmasked condition to determine the patient's ability to understand speech in the poorer hearing ear. For this type of comprehensive evaluation, a licensed audiologist and otologist should be included in the team approach to treatment.
Treatment
SSD is treatable. Prior to making treatment decisions, consider all diagnostic findings. Rule out any conductive or medically treatable condition that may contribute to the loss in either ear. Ensure there are no signs of retro-cochlear involvement in the hearing loss. Remember that SSD is a serious and potentially debilitating condition, but several kinds of treatment are available. In two recent cases, one patient preferred a monaural fitting, while the other preferred a multi-CROS (contralateral routing of signal) device.
The often forgotten or ignored multi-CROS is sometimes the answer for SSD, so don't rule it out until you have tested it. The multi-CROS, or bi-CROS, device is a hearing aid system that consists of a wireless system that connects a transmitter on the poorer ear to the hearing system on the better hearing ear. Both the transmitter and receiver hearing aid units can be fit wirelessly with in-the-ear (ITE) or over-the-ear/behind-the-ear (OTE/BTE) models. If frequent interference occurs, you may also order these units as a wired system. As sound comes to the transmitter on the poorer ear, it will electronically be delivered to the better hearing side with the sound being slightly different. This slight difference in sound allows most individuals to actually learn or re-learn to localize the direction of sounds.
Most professionals agree the two most effective treatments for SSD include the multi-CROS device or the bone-anchored hearing device (BAHA). Although the BAHA is a highly-effective treatment, it requires surgery and continuous upkeep of the internal and external components. Other treatment options include monaural fittings, aural rehabilitative strategies, such as preferred listening and seating positions, and noise reduction strategies.
Robin Donham, AuD, FAAA, CCC-A, is the national training manger for Interton.
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