By Audiologists at Midwest Hearing Center
I can hear just fine, I just cannot understand what people are saying,” is a phrase heard on a near-daily basis at most audiology practices. Another common complaint is that “people mumble too much.” The inability to discern what is being said is the most common complaint for most patients struggling with hearing loss. This comes from the difference between audibility and discrimination, or a high-frequency hearing loss.
Audibility is the capability to hear a sound, any sound. It is the ability to detect acoustic signals, in a variety of frequencies, volumes, and from a variety of sources. Hearing dishes clang together, birds chirping, and newspaper crunching are examples of signals that people who get hearing aids typically report are “new” or too loud. Speech discrimination is the ability of your brain to interpret sounds as words. This is a skill learned in infancy and can degrade as we age.
During a comprehensive hearing test, the ability to hear beeping sounds as well as speech discrimination is measured. Speech discrimination is measured as a percentage of words a patient is able to understand with auditory information only, i.e. no visual cues. Lists of phonetically balanced, standardized words are presented at a volume determined to give the patient maximum audibility. This way, we make sure most of the speech sounds are audible to the patient and eliminate this as an issue. If your discrimination score is 100 percent, you were able to understand every word in the test. A score of zero percent indicates you were unable to discriminate any words even when presented loud enough. This score is also used to determine how well we can expect a patient to understand words with hearing aids. Unfortunately, the ability to discern sounds as words can diminish as we age, even if audibility stays the same. This is regrettably, something that hearing aids usually cannot correct for. Increasing power to high frequencies can make things “sharper,” but this does not always help the situation.
When questioned, most people who say that they “cannot hear” someone, report that they heard them but did not understand all of what was said. A hearing loss that is worse in the high frequencies usually causes more issues with clarity of speech than an inability to “hear.” Often, audibility is the issue, not speech discrimination. In other words, when speech is presented loud enough, 100 percent of the words were able to be discerned.
Sometimes, a speech signal is not capable of being heard due to issues in the environment or the signal itself. For example, if you are in a loud restaurant, it is unrealistic to expect to hear the person on the end of a large table. If a friend always has an unusually soft voice, they will always be harder to hear than a friend who speaks loudly. However, there are a myriad of parameters that can be adjusted in hearing aids. Frequently, something can be done to alter the hearing aid signal to help with a majority of issues or frustrations. It is the audiologist’s job to listen to the issue and determine if that is a signal that the individual should be able to discriminate, or if that is an unrealistic expectation. If desired, there are accessories available, which connect to hearing aids, that can help with some of the very difficult situations.
For further information or to schedule an appointment to have your ears examined, please call Midwest Hearing Center at their Morton office at 309-284-0164 or their Peoria office at 309-691-6616.
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