to percentages no matter what anyone tells you.

Decibels vs. Percent

Sound intensities are indeed measured in decibels (dB). There are two reasons why you can never equate decibels to percentages. First, the decibel scale is open-ended like that of the Richter scale used for measuring earthquake intensities. To calculate a percent you need to know the maximum value possible. In both of these scales there is no limiting maximum value. Therefore, you cannot calculate a percentage. Any attempt to do so is just a bunch of meaningless gibberish!

Second, the decibel scale is logarithmic, while the percent scale is linear. Numbers that appear to be similar have vastly differing meanings. They are as different as trying to compare apples to elephants!

When people  talk about having a 50 percent hearing loss they likely mean that they have a 50 dB loss. Where did the idea come from that we can measure hearing loss in percentages? Here is how Brad Ingrao, an outstanding audiologist, explained it.

To measure sound intensity (the way audiologists measure it) you need to do a mathematical calculation that is so strange that 20 + 20 = 26 dB (SPL).

"To make a scale that makes sense to most people, a different equation is used to convert sound intensity using the Sound Pressure Level (SPL) scale to the Hearing Level (HL) scale that goes from 0 dB HL (normal threshold) to 120 dB HL (pain).

If we forget about hearing losses greater than 100 dB (like most people tend to do), we get 0 dB to 100 dB as the usable (dynamic) range of hearing for the average 'normal' ear.

Since doctors and audiologists tend to under-estimate their patient's ability to understand such things (or they don't understand it themselves), the erroneous concept of dB = % evolved."

Let's understand how this decibel scale works and why using a percentage value to describe our hearing losses is so very wrong.

First we need to understand that a decibel is not a given intensity (loudness) of sound, but rather, it is a ratio of how many times louder (or softer) a sound is than a given reference sound level.

This means that 0 dB is not the absence of sound, but is an arbitrary zero. We define it as the faintest sound that a young sensitive human ear can hear. Furthermore, because the decibel scale is logarithmic, every 10 dB increase in sound intensity is actually a ten-fold increase. Therefore, a sound intensity of 20 dB is not twice as loud as a sound intensity of 10 dB, but is 10 times as loud, and a sound intensity of 30 dB is 100 times as loud as a sound intensity of 10 dB. Similarly, a sound intensity of 50 dB would be 100,000 times as loud (10 x 10 x 10 x 10 x 10). This is how the decibel scale works. It is totally unlike the linear percent scale.

Now lets see the fallacy of trying to compare this "funny" decibel scale to the percent scale. To illustrate this, let's assume (remember this assumption we're making here is totally wrong) that 0 dB is equal to 0 percent hearing loss and that 100 dB equals a 100 percent loss. This would then mean that 50 percent would equal a 50 dB hearing loss, right? Wrong! Not by a long shot! A 50 percent hearing loss would equal, believe it or not, only a 3 dB loss! Looking at it the other way, a 50 decibel loss is not just half as loud, like it would be in a percentage scale, but would only be one thousandth of one percent as loud!

Here is another example. I have a 70 dB loss. This is not equal to a 70 percent loss by any means. In actual fact it means that the softest sound I can hear needs to be 10,000,000 times louder than the softest sound a person with normal hearing can hear. One out of ten million is definitely not a 70 per cent loss but would be a loss of 99.9999999%! Quite a difference, isn't it? Now you can see why we must never use percentages when talking about our hearing losses. They just do not equate. They are absolutely meaningless!

Percent Used to Describe Discrimination

Although we cannot use percentages to describe our hearing losses, we correctly use percentages to describe our ability to discriminate sounds. To determine our ability to discriminate between words, our audiologist sets the volume at our most comfortable listening level. She then has us listen to a list of words and we repeat back what we think we heard. The number we get right, converted to a percentage, becomes our discrimination score. Therefore, if I understood 80 out of 100 words in my right ear, my discrimination is 80% for that ear. I may have an entirely different result for my other ear. Consequently, we can correctly describe our ability to understand what we hear as a percentage. A person could correctly say that his discrimination is 78% in his right ear and 95% in his left ear. But this has nothing to do with the severity of our hearing losses as such.

Percentage and Hearing Disability

If your hearing loss resulted from an accident on the job, there is a formula that is used to calculate the percent disability pension for which you may be eligible. Don't get mixed up. This is not your hearing loss expressed as a percentage. Rather, this formula calculates how much your degree of hearing loss supposedly impacts your ability to remain employed at full wages.

For example, plunking your hearing loss levels into the formula may yield a result of 75%. This means that with your particular hearing loss, you may be entitled to a 75% disability pension. Again, this is not your average hearing loss expressed as a percentage.

Classifying Our Hearing Losses

Hearing health care professionals classify hearing into several categories such as normal, slight, mild, moderate, moderately severe, severe, profound and deaf. Not all of them use all of these categories, nor do they all use the same hearing loss ranges in each one. In the past, most used this simple scale.

Simple Hearing Classification Hearing Threshold

Today, research has shown that even hearing losses of only a few decibels can cause significant hearing problems. As a result, many hearing healthcare professionals have fine-tuned this scale to better reflect this reality. (Note that these ranges are arbitrary and may vary slightly among authorities.)

Today's Hearing Classification Hearing Threshold

Describing Our Hearing Losses

Unless you have a "flat" curve on your audiogram, how can you accurately describe your hearing loss? Your hearing loss could be different at every frequency so one word could be meaningless.

The best way is to be specific. If I have the typical "ski slope" hearing loss, I could describe it as, "I have a 30 dB loss at 500 Hz, dropping to 100 dB at 4,000 Hz." A more general way, but still accurate, would be to describe it as, "I have a mild loss in the low frequencies, dropping to profound in the higher frequencies.

The next best way to describe our hearing losses is to average the 4 frequencies that carry most of the speech information to arrive at a single figure. Use the following four frequencies—500 Hz, 1,000 Hz, 2,000 Hz and 3,000 Hz—and average the hearing loss at these frequencies to come up with one figure. However this method falls down if we only have a bit of hearing left in the very low frequencies. Incidentally, it is not right to take the average of our best and worst figures. That could give a very wrong impression of our hearing losses.

If you want a very simple way to describe your hearing loss, the most accurate (and simple) is to say you have either a mild, moderate, severe, or profound hearing loss. Your audiologist can tell you which category your hearing is generally in. (Remember, you could be mild in the low frequencies and profound in the highs—but to oversimplify, you can reasonably accurately reflect your practical hearing loss by using one of these categories.) It is much more meaningful, and far more accurate than trying to use a meaningless percentage. 

STOP being the ears of people with hearing loss in denial

Sergei Kochkin, Ph.D. Executive Director
Better Hearing Institute

One of the most aggravating aspects of living with an individual with hearing loss, who is in denial (everyone mumbles they say), is constantly repeating your self, speaking louder, or interpreting the world for them. There is a way to release yourself from this maddening co-dependent relationship and at the same time to motivate your loved to seek help for their hearing loss.

Dr. Richard Carmen  has done a masterful job of offering help to family members in his book How hearing loss impacts relationships: Motivating your loved one. In addition as advisor to the Better Hearing Institute he offers suggestions on our website under the title. 

I encourage all people caught in the trap of being the ears for their loved one to read Dr. Carmen's book and his advice on this website. But let me summarize the key aspects of how you can set yourself free:

• Understand that being the ears of your loved one is not an act of love.
• Assisting loved ones in denial is counterproductive and encourages co-dependent relationships. Continuing to give help could lead to your loved one's failure in life as well as impact many aspects of their quality of life such as performance on the job. It is important you understand the areas impacted by untreated hearing loss as documented on the Better Hearing Institute website.
• And remember if you continue to help them why should they seek help?
• Make it your ULTIMATE goal to have your loved one hear independent of you; and don't do it alone. Get your entire family and their friends in your corner in a productive conspiracy to get your loved one in denial to finally realize they have a hearing problem.
• Dr. Carmen's practical tips are: STOP repeating yourself! STOP raising your voice! STOP being the messenger by carrying the communication load for the family! In essence this means, STOP BEING THEIR EARS!

Here is one very clever intervention that could set you free. Explain to your loved one as follows in a calm, loving, non-condemnatory voice:

The whole family has had a talk. We believe you have a hearing loss and in the past we have helped you by speaking louder, repeating ourselves, or interpreting what other people have said. In effect we have become your hearing aid. But we realized this might not be the most loving acts we can do for you. We love you very much and want you to get help for your hearing loss. So from now on we will move toward stopping repeating ourselves when you say "Huh" or "What did he say?" and we will move toward no longer speaking louder so you can understand us. Instead we will simply say the words "Hearing Helper" (or choose another signal word that has meaning for your family) before we give you help. This is our signal to you that you have just asked us to be your ears. This is our way of demonstrating our love for you — that is by showing you how many times you ask for help. So for X period of time (e.g. a few weeks) we will continue to help you but we will preface our help with the words "Hearing Helper"…we think in a short period of time you will realize how many times you seek our help in hearing."

Many loved ones in denial will soon realize how much they use your ears; when this happens they will seek help. Encourage them in their journey to a world of better hearing. And enjoy your new found freedom!

(Note: this advice is ONLY for people in denial and who have not sought help for their hearing loss)

Another resource to provide you with access to many helpful hearing related articles.