silk nx CROS cic hearing aid

A Discreet Solution to Single-sided Hearing Loss

by Lisa A. Perhacs, AuD, Sivantos, Inc

Hearing loss doesn’t always affect both ears in the same way. In fact, millions of Americans have single-sided or unilateral hearing loss, meaning they have diminished or total hearing loss in one ear. Because they can still hear out of the other ear, many with single-sided hearing loss neglect to address their condition with hearing aids. Instead, they rely on their “good” ear to get by, but they can still be met with several challenges in their day-to-day lives.

Why would someone not want to use a device that could help them hear better? Unfortunately, the stigma about hearing aids making people seem old or out of touch is pervasive, and many people would rather ignore their hearing loss than have an “unsightly” hearing aid.

However, new technology may offer a solution—hearing aids that are made specifically to address single-sided hearing loss.


The effects of single-sided hearing loss


To understand how hearing aids can help individuals with single-sided hearing loss, it’s important to understand this kind of loss and how it affects people. Like most animals, nature provided humans with two ears. Rather than receiving separate streams of sound from each ear, the ears collect sound and send it to the brain, which processes the sound binaurally. This binaural hearing allows you to identify the direction from which sound is coming and hear it clearly. With single-sided hearing loss, that ability is lost.


If you only hear out of one ear, it becomes difficult to localize sounds and pinpoint the source of speech, especially in environments with loud background noise. Single-sided hearing loss also makes it challenging to understand higher-frequency sounds.


Unlike low-frequency sounds, which can bend around your head and are still often heard even when your good ear is facing away from the source, high-frequency sounds have shorter wavelengths, which get blocked by your head and can’t travel to the “good” ear. Since many consonant sounds fall in the high-frequency range, it can be challenging to comprehend speech and follow a conversation when it comes from your “bad” side.

Not only does untreated single-sided hearing loss diminish your ability to hear, but it also impacts how you live your life. You may have to ask people to speak on the side of your “good” ear, reposition yourself, or constantly turn your head during conversations. Doing this repeatedly just to follow a conversation can strain your neck and back.

Listening fatigue is another potential issue, as you can get tired from constantly working hard to listen to conversations and fill in the gaps and missing pieces of acoustic information. Additionally, there is also the risk of depression. If struggling to understand others takes too much effort or if you are tired of having to contort your body to hear them, you might choose to avoid social situations altogether, which can make you feel isolated and lonely—known contributing factors to depression.


Hearing aids to capture sound from your bad side


The most common way to treat single-sided hearing loss relies on contralateral routing of signals (CROS) hearing aid technology. This involves wearing a transmitter device, which looks like a normal hearing aid, on the ear with unaidable hearing loss, paired with a hearing aid on the better ear. Through this approach, the sound coming into your “bad” ear is picked up by the transmitter, processed, and transmitted to the hearing aid and into your “good” ear. If you have a degree of hearing loss in your other ear, the paired hearing aids can also amplify sounds heard on both sides in the better ear (known as BiCROS).


Traditionally, CROS type systems relied on bulky wires to connect the hearing aid and transmitter device. While technology has advanced to allow CROS hearing aids to connect to each other wirelessly, they have only been available in behind-the-ear devices, which don’t provide the level of discretion many wearers desire.


CROS silk nx cic

Recently, Signia introduced the first CROS technology in a tiny (CIC) hearing aid that sits directly in the ear canal, rather than behind the ear. This new technology offers people experiencing single-sided hearing loss with advanced wireless technology–allowing to let them pick up sound from their unaidable side–and also the discretion of having a nearly invisible hearing device.

Like many modern hearing aids, the settings of Signia’s new CROS Silk Nx CIC can be changed remotely via a smartphone app.


Advanced technology to address single-sided hearing loss


Using advanced technology in modern hearing aids to address single-sided hearing loss, users can essentially hear binaurally, improving their ability to localize sound and understand speech from any direction.

This can help improve overall health and safety, enabling the user to process sounds no matter where they originate from, and hear potential danger that might otherwise be missed. Furthermore, today’s innovative hearing technology now allows people with single-sided hearing loss discreet options that had previously been unavailable to them.



Lisa A. Perhacs, AuD, is a Clinical Education Specialist for Sivantos, Inc. She is responsible for training customers and sales staff on the company’s current technology and products. She conducts training sessions in customers’ offices, remotely, via webinars, and at regional and national events. Dr. Perhacs has more than 13 years of manufacturing experience including two years as the Training and Audiology Manager for Siemens Export Sales, based in Erlangen, Germany. Her six years of clinical experience includes private practice, a large medical setting, and Clinic Coordinator and Preceptor at Montclair State University. Dr. Perhacs earned her undergraduate degree from Seton Hall University, graduate degree from The College of New Jersey, and doctorate from Pennsylvania College of Optometry (now Salus University).




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HHTM's mission is to bridge the knowledge gaps in treating hearing loss by providing timely information and lively insights to anyone who cares about hearing loss. Our contributors and readers are drawn from many sectors of the hearing field, including practitioners, researchers, manufacturers, educators, and, importantly, consumers with hearing loss and those who love them.