Why do I sometimes hear but not understand?

Why do I sometimes hear but not understand?

To someone without  a hearing problem, this seems ridiculous.  If one can hear, why can’t one understand? Don’t hearing and understanding automatically go together?  The answer to this question is “No.” One can hear without understanding, if the hearing loss has been present for some time, or if only some frequencies (“pitches”) of sound are being heard.  This type of situation can be very frustrating, both for the person experiencing the hearing loss and for those who are trying to communicate with that person. Often the person experiencing the loss becomes tired of asking others to repeat what they say, and stops even trying to understand.  People speaking to this person may think that he or she is ignoring them.   Hearing correction can be thought of as “communication maintenance.”

In order for sound to be interpreted, or “understood” by the brain, a series of complex events must occur.  When a person experiences a hearing loss, only part of the sound that is necessary for full understanding reaches the brain.  As a result the words may sound garbled, mumbled, or just plain unclear, especially when there is background noise present.  Many times the person with the loss can understand what is going on around them, but it is a struggle trying to piece together the available information, and can make listening situations more of a chore than enjoyable.

The process of interpreting sound correctly takes years to develop in humans.  An infant can hear sounds, but doesn’t know what they mean.  As the infant grows, he or she will learn to understand speech.  Likewise, an adult may “hear” a language, such as Chinese, but won’t understand it unless he or she has learned the language.  When a hearing loss occurs over a long time, the brain “forgets” how to understand sounds.  Just like someone who learned Chinese in school but hasn’t used it for many years, the sounds can be heard again, but not necessarily understood. 

Nothing can be done to “cure” this condition.  The question is, can anything help in this situation?  Yes.  Hearing instruments can amplify the sounds that have not been reaching the brain to make it easier to understand.  A proper fitting is crucial for this benefit: every hearing loss is different, and every ear will need a different combination of frequencies in order to get optimal results.  Many factors must be taken into account, including the degree of loss, which frequencies are affected, the sensitivity to loud and soft sounds, the shape of the ear, and the person’s listening environments. 

The results of a hearing instrument fitting will vary from person to person, depending on all of those factors and how much the ability to understand has diminished.  When a hearing instrument amplifies sound enough to get it to the brain, the brain must “relearn” how to understand the sounds.  In the case of a longstanding loss, some of this understanding ability, what hearing professionals term “speech discrimination,” may be permanently lost.  In other words, even with  the best hearing aid fitting in the world, a person will always have difficulty  understanding certain sounds as words.  In a case such as this, the hearing aids will improve understanding to a degree, but more importantly, will help slow down the process of further loss.  One of the critical factors in correcting a hearing loss is to do it as soon as possible.  Hearing loss is a subtle process, and often is not recognized by the person experiencing it.  A professional hearing evaluation is the only reliable way to detect a hearing loss in its early stages.