It’s pretty easy to see the impact of vision on our lives. It would be hard to go a day without interacting with someone wearing glasses or contact lenses. Yet when was the last time you met someone with noticeably impaired hearing?
Even if you have perfect 20/20 sight, you may have undergone a vision test at some point in your life. Most people have at least a vague idea of how good their vision is, but can you say with any certainty what your hearing range is?
If not, don’t be surprised. Very few Americans would be able to say that they’ve had a hearing test. An estimated 35 million Americans suffer from hearing loss, and only 28.5 percent of them use hearing aids. Approximately 25 million Americans with hearing loss do not use a hearing aid, and a large percentage of them would never have bothered with a hearing test.
Hearing range defined
Most eye tests measure how far you can see, so hearing tests would probably be about how close a noise has to be for you to hear it right? Kind of, but not really. When people use the term “hearing range,” also known as “dynamic hearing range,” they’re talking about the spectrum of sound between the absolute softest sound you can hear and the absolute loudest sound you can tolerate.
The science bit
While it may not be the most engaging part of the article, any hearing range discussion worth its salt would have to dive into the science behind hearing ranges. As you may know, sound volume is measured in decibels. The normal hearing threshold (how loud a sound needs to be for someone to hear it) is between 0-20 dB, whereas the average discomfort levels are 90+.
To give these numbers some meaning, 20 dB is the sound of leaves rustling, 85 dB is the sound of loud traffic, and 180 dB is the sound of a rocket launch.
Let’s say your hearing threshold is 10 dB, and your discomfort level is 90 dB. The difference between these numbers is 80, which would make your dynamic range 80 dB.
But I thought hearing range was…
Maybe you’ve read up until this point and been confused about why we’re talking about volume. In everyday vernacular, hearing range usually refers to the frequency of a sound- how high or low pitched sounds may be. But really, hearing range is a combination of volume and frequencies.
Sound comes in a dizzying amount of frequencies, all of which may or may not be audible to certain people. Frequencies and volume are to the ear as colors and definition are to the eye. And much like some people have trouble distinguishing colors, some people are unable to hear certain frequencies.
When you combine audible volumes and frequencies, you get a graph that depicts the average human auditory field.
What can affect a person’s hearing range?
Some people are taller than others, some people have blue eyes, and some people have a wider hearing range. Like anything to do with the human body, natural variation means that an individual’s hearing range is unique. Then of course, as hearing degrades, a person’s hearing range may diminish and change as they age.
Beyond this, there are other conditions that may lead to a significantly different hearing range. Firstly, we have a condition called “recruitment.” This condition is often paired with damage to the cochlea, a component of the inner ear.
When one of the hair cells in the ear canal dies, the cell “recruits” neighboring cells to take over. This neighboring cell is now responsible for not just the frequency it originally picked up, but also for the frequency that the damaged cell was responsible for.
This means that, while it will take a louder sound to break the individual’s hearing threshold, once a sound does break through, it will be louder than normal and might shock or disturb the listener.
Secondly, we have hyperacusis. While recruiting generally happens with age, due to the hair cells being damaged, hyperacusis can affect anyone of any age. It is identified as hypersensitivity to certain kinds of noise, whether that noise is a knife scraping across a plate or fireworks. There is still no firm understanding of the cause behind this condition.
What is loudness discomfort levels (LDL)?
The loudness discomfort level (LDL) is the intensity of sound at which a patient reports sound to be uncomfortably loud.
It should be noted that the loudness discomfort levels are variable between individuals, with a normal variation of about 20 dB. This means that one person may have a LDL of 90dB and another may have a LDL of 110dB at the same frequency.
People with hearing loss may also have reduced loudness discomfort levels because hearing loss changes our psychoacoustic perceptions of sound. This is called loudness recruitment.
How are loudness discomfort levels used?
Loudness discomfort levels may be measured during a hearing evaluation, although it is not as common of a practice as it used to be. They are measured at different frequencies, usually 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz using either pulsed tones or narrow band noise. LDLs may also be measured for speech stimuli.
Loudness discomfort levels are used by hearing healthcare professionals when fitting hearing aids. The LDL must be measured to determine the patient's dynamic range of hearing, which is the range of intensities from the softest sound the patient can hear to the loudest sound they can tolerate.
The purpose of determining the patient's dynamic range is the ensure that the hearing aid amplification remains within the comfortable levels of the listener. If LDLs are not measured, an average LDL is used.
Loudness discomfort levels are also commonly measured during a tinnitus evaluation or if hyperacusis is suspected. Reduced loudness discomfort levels is an indication of hyperacusis, and classification of the severity of hyperacusis can be determined based on the LDLs. For example, LDL levels of 95 dB or greater are considered normal. LDLs between 80-90 dB can be considered mild hyperacusis or sound sensitivity, whereas LDLs below 60 dB is considered severe hyperacusis.
Methods for Measuring Loudness Discomfort Levels
The most popular is using the Cox Contour Test loudness descriptors. In this method, the patient is presented with a frequency-specific tone or noise stimuli and asked to rate the loudness, as the stimuli volume is slowly increased.
The Cox loudness categories are:
7. Uncomfortably loud
6. Loud, but o.k.
5. Comfortable, but slightly loud
4. Comfortable
3. Comfortable, but slightly soft
2. Soft
1. Very soft
Once the patient indicates that the sound has reached #7, uncomfortably loud, the volume is not increased and that dB value is graphed on the audiogram.
So what’s my hearing range?
That is a good thing to be asking. As far as frequency goes, you can find a multitude of online tests to find your hearing frequency range. Testing volume, however, is a bit more complex. There’s no surefire way to test volume online, as speaker and headphone volumes vary so much.
About our links
Clear Living is reader-supported. By getting in touch with Clear Living you can be matched with a hearing specialist local to you, and arrange a free hearing test and consultation. We may receive a payment for the introduction. This is to help Clear Living remain free to provide advice and reviews, carries no additional cost to you, and doesn’t affect our editorial independence.
Comments
Clear Living values your comments but kindly requests all posts are on topic, constructive and respectful. Please review our commenting policy.