Your Hearing: How it works and how can we measure it?
How We Hear
Healthy inner-ear nerves (hair cells) are the key to good hearing. Although some die off naturally as you age, many more are killed early if your ears aren’t protected from harmful noise
Hearing is measured by a professional with an audiometer that sends tones to each ear through earphones. You listen carefully and respond each time you hear a tone. The levels at which you can barely hear the tones are your hearing threshold levels.
Your thresholds (measured in decibels) are recorded on a chart called an audiogram, for tones at different pitches or frequencies (measured in "Hertz," which is a special term for cycles/second). Normal thresholds fall within the unshaded area on the chart. When hearing loss occurs the thresholds fall into the shaded areas, meaning sounds must be increased in level for you to hear them.
It is a good idea to have a complete hearing evaluation even if you don’t suspect a hearing problem. This gives you a baseline against which to compare future audiograms if problems occur. Professionals suggest evaluations every 10 years; more often for those over 50. If you anticipate regular exposure to high-level noise, for example if you are an avid recreational shooter, you may wish to obtain more frequent tests until you can assure that your hearing is stable. Unusual changes would alert you and your hearing specialist (audiologist or otolaryngologist) to look for noise-related (inadequate or improperly fitted protection) or medical causes before it’s too late.
Learn more about Noise Reduction Ratings.