I am going to explain the basic concepts of an audiogram so that beginners can interpret it correctly. For this, I will use an audiogram kindly provided by a user from the APAT forum.
There are different types of hearing tests. I will explain the pure-tone audiometry, which is the most common, as well as the test used to determine the presence of hyperacusis.
The most common cause of hyperacusis is acoustic trauma, either acute (a single exposure to a very intense level) or chronic (sustained exposure over time to high levels). However, there are many causes that can lead to hyperacusis which, as we see in the following table, are not directly related to the inner ear as one might initially think.
The main symptom of someone suffering from hyperacusis is intolerance to moderate or even mild sounds. Exposure to sounds causes discomfort and pain, and sounds are perceived as louder than they really are. It can occur in one or both ears.
Although I have already briefly explained what misophonia and phonophobia consist of in Basic Concepts of Hyperacusis, the importance of these auditory disorders in conjunction with hyperacusis can be such that it is worth delving deeper into them.
Among the different auditory disorders in which the patient shows sound intolerance, misophonia and phonophobia are those in which, according to Dr. Jonathan Hazell, “the auditory pathways may function normally, but there is a strong abnormal reaction of the limbic system and the autonomic nervous system, to which the auditory system is closely connected.” Thus, unlike hyperacusis or recruitment, where there is a physiological problem, misophonia and phonophobia are psychological disorders caused by previous negative experiences with certain sounds. However, in the case of misophonia, not all cases are attributed to negative experiences with sounds. Some specialists, such as neuroscientist Aage R. Moller, consider that this condition is not learned but innate, and responds to some “physiological anomaly” in the areas of the brain activated by sound processing. On the other hand, audiologist Marsha Johnson points out that there seems to be a genetic component, as often members of the same family share this problem.
When talking about hyperacusis, it becomes inevitable to use certain terms related to acoustic physics or simply auditory medicine. For those who are unfamiliar with the meaning of words such as frequency, bandwidth, octave, etc., I will explain here exactly what all those terms mean in order to facilitate the understanding of the articles hosted on this blog.
To protect ourselves from loud sounds or sounds above our tolerance level, we can use earplugs or earmuffs. In the case of earplugs, there are several types: foam, silicone, moldable silicone, custom molds, filtered plugs, musicians’ plugs… Each type offers different levels of protection (from 9 dB up to 33 dB or more), with foam and moldable silicone plugs providing the highest protection.
Hyperacusis is an auditory disorder in which sounds are perceived as louder than they really are and/or the pain threshold is reduced to levels that affect daily life. Everyday sounds such as clinking dishes, children screaming, dog barking, crumpling plastic bags, the sound of small speakers like those of a mobile phone or laptop, vehicle traffic noise, or even the human voice become intolerable.
