The term “binaural” simply means “two ears.” When evaluating hearing sensitivity, the right, and left ears are tested individually both for threshold measurements and word discrimination ability. We expect the hearing and discrimination ability to be symmetrical between ears. There are some examples of times when it is not, such as a retired truck driver with poorer hearing on the left due to years of wind and road noise on that side or a hearing loss in only one ear following a viral infection.

Generally, though, asymmetrical hearing loss is caused by referral to an ear, nose, and throat physician for further investigation to rule out causes like acoustic neuroma, a type of benign tumor on the auditory nerve. When hearing loss is discovered in both ears, the standard recommendation is to fit the patient with two hearing aids. 

In this article, we will shed some light on what is binaural amplification and when to use binaural amplification hearing aids.

History of Binaural Amplification Technology

History of Binaural Amplification Technology

The strong recommendation for binaural hearing aid fittings is relatively recent. Prior to the 1980s, less than one-quarter of hearing aid fittings were binaural, with a steady increase to the present day, where approximately 85% of patients are fit with two hearing aids (Strom, 2021). Part of the historic recommendation for monaural fittings may have been due to a disconnect between audiologists, who performed the diagnostic testing, and the dispensers who sold the hearing aids. It was considered greedy or unethical to try to sell a patient two hearing aids.

Additionally, at the time, there was minimal research to support the benefits of binaural hearing for these patients. Fortunately, several prominent researchers published papers throughout the 1980s demonstrating the benefits of binaural amplification, and in 1978 the Supreme Court demanded that the American Speech-Language-Hearing Association (ASHA) lift the ban on hearing aid dispensing for audiologists. This allowed the process of diagnostic testing to hear aid fitting to move much more smoothly, and clinical audiologists were able to see the benefits firsthand in their patients (Strom, 2021).

Binaural Amplification Hearing Aids Benefits

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Center for Neural Science

So, what are those benefits? We have two ears for many reasons, the first of which is sound localization. The minute differences in frequency and intensity perceived by the right and left ears help us to judge where sound is coming from, which is critical for safety. It can be quite disorienting to have difficulty determining where sound is coming from and frustrating in day-to-day life. 

Research has also shown that hearing in noise is improved with two ears and that there is simply less listening effort and brain fatigue with two ears compared to one. There is a lot of hearing that occurs at the level of the brain, where the central auditory system takes the input from the right and left ears and integrates it to make better sense of your surroundings and to improve speech understanding. We hear with our brains, not just with our ears, and the system simply functions better as designed with two inputs. All of this applies whether we are considering two normal hearing ears or two hearing aids. 

When hearing aids are introduced, it is important to fit a symmetrical hearing loss with two hearing aids because there is strong evidence that a monaural fitting can result in the deterioration of hearing in the unaided ear. This is known as auditory deprivation. Patients with tinnitus will also find greater relief with a binaural fitting, and those with corresponding vestibular challenges also benefit from balanced hearing between the two ears. While hearing aids are very different from glasses, consider that you would never choose to wear a monocle if you were struggling with vision loss in both eyes. It is natural to provide equal inputs from the right and left sides to the brain.

Image Credit: ENT & Audiology News

Binaural Amplification Hearing Aids vs. Monaural Hearing Aids

There are a few instances where a monaural hearing aid fitting might be recommended, the most obvious of which is for patients with hearing loss in one ear and normal hearing in the other ear. In cases of single-sided deafness (SSD) where the unilateral hearing loss is too great to benefit from traditional amplification, audiologists might recommend a CROS (contralateral routing of signal) device which would transmit the sound from the deaf ear to the normal ear. Others will recommend a bone-anchored hearing device, which would send the signal to the better cochlea via bone conduction. Cochlear implants are increasingly recommended for this SSD population as well, although they are not always covered by insurance for this indication. 

A monaural hearing aid would also be recommended for a patient who is fit with a cochlear implant on one side; this is actually referred to as a “bimodal” fitting, as one ear is receiving electrical stimulation via the implant and the other ear is receiving acoustic stimulation via the hearing aid.

Finally, there is a somewhat rare condition known as “binaural interference,” where patients may actually perform poorer with input to both ears compared to one ear. This is something that can be assessed using tests of speech recognition in a soundproof booth presented to each ear individually and then to both ears together at comfortable listening levels.

Differences In Old Hearing Aids And New Hearing Aids

While traditional analog hearing aids essentially just made all sounds louder, the digital hearing aids of today are much more sophisticated. They take the patient’s specific hearing loss into account in terms of how much amplification to apply at each frequency, and they also communicate with one another to make split-second, real-time decisions regarding noise reduction and directionality. We know from the research that two ears or two hearing aids are preferable when listening to noise. If you add the newer advancements in binaural microphone technology, the benefits are even more substantial. 

Newer hearing aids can also make use of modern Bluetooth and other streaming capabilities, which are more user-friendly when delivered to both ears. If you have ever tried to take a phone call in a noisy environment and struggled to hear the phone while covering your other ear with your hand, consider how much easier it is to hear on the phone when the call is coming through your AirPods or other bilateral headphones. This improved ease of listening would apply not just to phone calls but also to any media you would like to listen to, such as music, podcasts, or audiobooks. 

Binaural Hearing Aids Cost

One obstacle to obtaining hearing aids for many patients is the overall cost. It might be tempting to consider purchasing just one hearing aid rather than two for cost savings, but it is not a wise choice. Remember that there is research showing deterioration of the unaided ear in these instances, so you may end up in a situation where your hearing is poorer and asymmetrical compared to before your hearing aid fitting. Note that hearing aids, in general, do not make your hearing worse. This is the result of an unbalanced input to the auditory system.

Additionally, a monaural hearing aid fitting is likely to result in lower overall satisfaction than a binaural fitting; you may not perceive enough of a benefit with just one hearing aid to justify the expense, and you are missing out on all of the built-in binaural features for improved listening and ease of use that come with two hearing aids. 

Related Article: Hearing Aid Costs

hearing aid costs

If hearing aids seem cost prohibitive, consider purchasing the entry-level technology, which will be on the lower end ($2,200-$3,000 for a pair), rather than the higher-level technology. While you might miss some of the bells and whistles of the advanced features, it will give you a good sense of whether hearing aids are offering you good benefits and an improvement in quality of life. 

There are ways you can make hearing aids more affordable, such as pricing them at different types of settings (university clinic, hospital, big box store), obtaining donated hearing aids from a church or other charitable organization, or using a payment plan offered by an office to pay them off over time.

Binaural Amplification Hearing Aids Takeaway

Ultimately, hearing loss often results in people isolating themselves or refraining from doing things they once enjoyed because they feel the strain on communication. Binaural amplification hearing aids are the best opportunity to get those enjoyable activities back in your life, which has larger implications as far as social and emotional health, as well as cognition and lowering your risk of dementia.

If you are noticing difficulty hearing in one or both ears, it is a good idea to have your hearing tested by an audiologist. This is the first step to determining whether you are a good candidate for hearing aids, and the professional will provide guidance regarding the most appropriate fit for your specific hearing loss.

erin edwards aud
Clinical Audiologist at Towson University | + posts

Erin Edwards received her Doctor of Audiology degree from Towson University in 2015 and her Ph.D. in Education and Leadership from Pacific University in 2022. She has worked with patients of all ages in a variety of settings and has a specific interest in cochlear implants, the relationship of hearing loss and dementia, and interdisciplinary healthcare.

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