You had a hearing test more than 5 years ago and were told you had normal hearing. You’ve noticed some problems hearing lately and have begun to wonder if you no longer have normal hearing. But you might also be wondering what exactly does it mean to have normal hearing?
Part of the test that we do involves having you listen to a series of tones at different intensity (volume) levels measured in decibels and at different frequency (pitch) levels measured in hertz . From your responses we get an overall picture of your hearing threshold levels across the range of frequencies that correspond closely to the region in which speech occurs.
What is normal hearing?
We use tones and words to assess hearing ability. Tones are presented a series of loudness levels (decibels) and across a range of pitches (frequencies). Words are presented at both a volume level loud enough for your to hear the word and at volume levels that decline in loudness. From this information we derive a picture of your ability to hear. The table below shows one of the more common systems we use to classify hearing levels. The numbers are representative of a patient’s range of hearing levels in decibels (dBHL).
Degree of Hearing Loss
Normal, –10dB to 25dB
Mild, 26dB to 40dB
Moderate, 41dB to 55dB
Moderately Severe, 56dB to 70dB
Severe, 71dB to 90dB
Profound, 91dB+
How can hearing levels be below zero?
Yes, you’re reading that correctly the range above for “normal” hearing is from (-10dBHL to 25dBHL). (Zero) 0dBHL does not mean that there is no sound at all. Rather, it is the softest sound that a person with “normal” hearing ability would be able to detect at least 50% of the time. Most audiograms begin below 0. 0dBHL is the softest sound that the average normal listener can detect. Which means there are plenty of people who have hearing levels that are above average (meaning they can detect sounds below 0dBHL).
The measurement of a decibel can be a little confusing. A decibel is a unit used to express relative difference in power or intensity. On the decibel scale 10 dBHL is 10 times more powerful is 0 dBHL. A sound 100 times more powerful than 0dBHL is 20 dBHL. A sound 1,000 times more powerful than 0dBHL is 30 dBHL.
In a nutshell, a drop in your hearing levels from 0dBHL (normal) to 25dBHL (borderline normal) is a big change.
The next step
Your takeaway from all this should be how your ability to hear is impacting your life. If you had your hearing checked 5 years ago and your threshold levels were at 15dBHL and they’ve now declined to 35bHL that change is going to be quite noticeable to you. If you’re an active person who enjoys spending time with friends and family, this change in your hearing levels from the “normal” range to the “mild” range is a problem.
Contact our office and schedule an appointment for a hearing test. We can tell you immediately if you do have a problem and provide solutions to the problem. Don’t wait call today.