Do I Really Need Two Hearing Aids?

Posted: January 21 2022

If you or someone you know has been diagnosed with hearing loss, you may be wondering whether two hearing aids are necessary, or if one is sufficient. In the majority of cases, individuals with hearing loss will benefit most from wearing a set of two hearing aids. That said, there are a few situations in which the audiologist may recommend only one hearing aid. For example, if a person has hearing loss in only one ear, then they likely only need a hearing aid for the ear with hearing loss. Similarly, if a person’s hearing ability is too poor to even benefit from a hearing aid in one ear, the audiologist will not recommend a hearing aid for that ear. Despite these exceptions, research shows that in approximately 85-90% of cases, two hearing aids is the recommended treatment plan for individuals with hearing loss in both ears (Ricketts et al). 

Why Are Two Hearing Aids Better Than One? 

We’ve all had the experience of sitting in a noisy dining room and struggling to hear what a friend is saying. You might ask your friend to repeat themselves to have another chance to interpret what they said. Often, after a second chance, their message is faithfully received and the conversation can carry on. Similarly, when hearing with two ears, the brain gets two chances to pick-up meaningful information and interpret it correctly. In other words, your ears work best as a team! When a person has hearing loss in both ears, and only wears one hearing aid, they are only giving their brain a single chance to correctly interpret information. This results in more misunderstandings, more frustration, and poorer communication. 

Improved Speech Understanding in Noise:

Similarly, when we hear with two ears, the brain is able to combine information from both ears centrally. Not only does this allow the brain to piece together the complete message, but it also allows it to analyze differences between the sounds arriving at both ears. Through this analysis, the brain can separate speech sounds from background noise, improving our understanding in noisy environments. This phenomenon is known as the “bilateral squelch effect,” which just means that we hear better in noise with two ears as opposed to with just one ear. 

Better Sound Localization:

By analyzing the differences between sounds that arrive at both ears, the brain also determines where a sound is coming from. Due to a phenomenon called the head-shadow effect, sounds originating from a person’s right side will arrive at the right ear a little bit sooner and a little bit louder than they will to the left ear. These differences alert the brain that what it’s heard must be on the right side. Research shows that this improved localization ability also occurs in individuals with hearing loss who wear two hearing aids (Simon 2005). 

Better Sound Quality:

When we hear with both ears something called the “binaural summation of loudness” occurs. This means that sounds are perceived as louder when heard with two ears, even if the volume of that sound hasn’t actually been changed. This is because the two sound signals become fused. Similarly, when we hear with both ears, things generally sound fuller and more balanced. If you don’t believe this, try putting in an earplug and listening to some music. Then try the same thing without the earplug. 

Prevent Speech Understanding from Degrading:

When someone with hearing loss in both ears wears only one hearing aid, the aided ear becomes the dominant ear. Because of this, the brain pays less attention to the information it receives from the unaided ear as it is simply not as useful. Over time, the ear without a hearing aid actually gets worse at transmitting speech information to the brain. This is known as the “unaided ear effect” and it occurs in as many as one-third of people who wear one hearing aid when two are recommended. The greater the hearing loss severity, the more susceptible a person is to this effect. In some cases, speech understanding in the less dominant ear can improve after being fitted with a hearing aid, but this is not guaranteed.

There are a number of reasons why two hearing aids are most often better than one. If you are experiencing difficulty hearing, make an appointment with an Audiologist at East Coast Hearing at www.eastcoasthearing.ca. Our licensed Audiologists will help determine the ideal hearing solution for you.

Author: Evan Mahaney, Audiologist, East Coast Hearing