How Bad Is My Hearing
The first step in assessing eligibility for insurance benefits is to ascertain the degree of your hearing loss. Everyone's loss is different, but oddly, there is a generally accepted method by which the degree of loss is measured.
The calculation starts with a pure-tone audiogram, which plots the loudness level (in decibels) at which you perceive sound at different frequencies or pitches (measured in megahertz). Most hearing loss occurs in high tones. For example, at a very low frequency or pitch of 125 hz -- the equivalent of a really low note on a cello -- the decibel threshhold might be 25, meaning you can hear a relatively soft note. At a very high frequency of 6,000 hz -- the chirp of a cricket -- the threshhold at which you first hear the tone might be 100 decibels, a level that someone with full hearing would find quite painful.
Although the matter is the subject of considerable debate, the generally accepted rule, which Washington courts use, is that the critical frequencies for understanding speech are 500, 1,000, 2,000 and 3,000 hz. So to determine a percentage of hearing loss, you average the decibel threshhold shown on the audiogram for those four frequencies (if the db threshhold is over 100 db, you use 100).
That's far from the end of the calculations. Audiology professionals generally agree that one's ability to function doesn't begin to drop until the decibel threshhold reaches 25 db. On the other end of the spectrum, they agree that if the average threshhold is greater than 92 db, the person has no useful hearing. So to take those outer boundaries into consideration, you subtract 25 from your average threshhold, then multiply the remaining number by 1.5. The resulting number is your percentage hearing impairment in that ear.
One last computation is needed. One ear is not as good as two, but we'll do most of our hearing through our good ear. So rather than simply taking an average of each ear's threshhold, you give five times the weight to the better ear. Your overall hearing impairment, then, is five times the better ear plus the worse ear, divided by six.
Here is an example -- these values come from my most recent audiogram. My better right-ear threshholds are 50 db at 500 hz, 80 db at 1,000 hz, and in excess of 100 db at 2,000 and 3,000 hz. The total is 330, and the average is 82.5. Subtracting 25 and multiplying by 1.5 equals 86.25 percent impairment in that ear. My left ear threshholds at the four relevant decibel levels are 65, 85, 100 and 100 for a total of 350, an average of 87.5, and an impairment percentage of 93.75. Multiplying the better-ear number by five, adding the other number and dividing by six yields an overall impairment percentage of 88.5.
Here is the worksheet used by Washington physicians to calculate hearing loss.
Now it's critical to remember that the numbers don't tell the whole story -- not by any means. In the first place, impairment is calculated without our hearing aids, and good aids can reduce our level of impairment dramatically. Whether our loss occurred before or after we learned to speak has an enormous impact on our ability to speak clearly. Our speech-recognition (lip-reading) skills vary enormously.
The audiogram and impairment calculations may describe our hearing loss. But those number need not define or limit us as individuals. With the help called for by state and federal law, we can fully function in a hearing society. My law practice is dedicated to ensuring that result.
