By Courtney M. Campbell, Au.D.
Hearing speech in the presence of background noise is very difficult for people who have a hearing loss. This difficulty can occur regardless of age, degree of hearing loss, or which hearing aid is being used.
What is important to know is that hearing—and understanding— speech in the presence of background noise is a complex physiological process. Wearing a hearing aid can usually improve the way sounds are presented to the ear, but it cannot change the way your brain processes the signal your ear receives.
Auditory training can help improve the brain’s ability to understand speech in noise, but keep in mind it requires a time commitment.
Hearing speech in the presence of background noise, like in large crowds, is very difficult for people who have a hearing loss, even when a hearing aid or cochlear implant is used.
The way hearing loss affects the way we hear, especially in noise, is more complicated than most people realize. As you probably know from reading Hearing Health Foundation’s communications, hearing loss occurs when hair cells in our inner ears die or are damaged. The loss of these cells affects not only how loud a particular sound needs to be for you to hear it, but also how well you understand speech and how well you discern speech in the presence of background noise.
It is crucial that all three of these areas be tested during your audiological evaluation, and then discussed. The results of these evaluations are very important for both the hearing healthcare provider and the patient to know and understand.
For example, if I have a patient with a moderate hearing loss but poor word-recognition ability and a severe difficulty understanding speech in the presence of background noise, it is my responsibility to discuss these results in detail with the patient in order to set up realistic expectations about their hearing aid usage.
This is because this patient—even with the best hearing aids on the market—will probably still struggle in very noisy situations.
When a very severe deficit for hearing in noise is present, there are some supplemental devices that can help enhance what is called the signal-to-noise ratio. The signal-to noise ratio is the amount of difference between the signal (speech) and the noise. As a general rule, most people hear and understand speech better the larger the difference between the signal and the noise.
Assistive listening devices such as frequency modulation (FM) systems and remote microphones can be used in addition to hearing aids to maximize the signal-to-noise ratio.
These devices are usually worn by the speaker or passed between speakers, sending their voice(s) directly into the hearing aids. This allows for a louder, clearer signal for the listener. For a patient like the one described before, I would suggest that they consider an assistive listening device to use in very noisy places.
If you are continuing to struggle to hear in environments with a lot of background noise, even while using hearing aids, make sure that your hearing healthcare provider conducts a thorough hearing exam that includes word-recognition testing as well as speech-in-noise testing.
Once these test results are explained to you, you’ll understand better about how your ears are processing sound even with the use of hearing aids, and your expectations will be more realistic. And don’t forget to ask your hearing professional about assistive listening devices.
An audiologist at Advanced Hearing Services in Virginia, Courtney M. Campbell, Au.D., received her undergraduate and doctorate degrees from the University at Buffalo in New York. She has a hearing loss and has been wearing hearing aids for over a decade. This article originally appeared in the Spring 2014 issue of Hearing Health magazine.
