Noises are everywhere, but the average listener may not notice them, Dr. Lori Zitelli, Aud, CH-TM, Managing Audiologist, UPMC Department of Otolaryngology, said in the Eye & Ear Foundation’s July 15th webinar, “Decreased Sound Tolerance: Managing Reactions to Bothersome Sounds.” If a person has negative reactions to a sound that would not cause the same reaction in an average listener, however, that person has decreased sound tolerance (DST).
Dr. Zitelli took the audience through a restaurant scenario to illustrate some sounds that might be encountered in this type of environment. Maybe there is a woman sitting at your table, swinging her legs as she eats, making a rhythmic thumping against the table leg. This is bothersome even when her foot does not make contact; just the sight of your foot moving is something you cannot look away from. Or maybe there is a woman sitting by the window playing a game on her phone with notifications turned up. She is not wearing headphones, so a constant stream of beeping and buzzing sounds is noticeable. Plates and silverware clinking in the kitchen carry through the restaurant. A woman in the corner is cutting pizza for her young child, scraping the dish with utensils in a way that you cannot believe is not bothersome to her. The lights are making a horrible buzzing sound that feels like it is growing louder by the second. The cash register dings every time someone pays. A woman beside you slurps as she eats her noodles, and you are surprised that the man next to her has not told her to knock it off.
Many of these sounds are completely out of our control, so a person with DST may be hesitant to put themselves in this kind of situation.
How the Brain Processes Sounds
Our hearing pathway is comprised of three different components: outer, middle, and inner. Sound waves come down the ear canal and vibrate the eardrum. On the other side, attached to the eardrum are the three smallest bones in the body whose purpose is to convert the energy that is traveling into mechanical energy that can transmit through fluid. The inner part of the ear – filled with fluid – is the cochlea. Hair cells, the sensory organs of hearing, are activated and generate an electrical signal that goes through the hearing nerve and into the brain. There is a lot happening in a short period of time involving a lot of different systems.
The subconscious portion of our system detects electrical energy and processes it. Every sound we hear in our environment is made up of a specific pattern of pitches; the brain has the ability to recognize them even if happening at the same time. The cortical areas of our brain register the perception of sound and decide whether it is important.
For those who simply experience environmental sounds, this is the extent of the pathway. For others, their brains may perceive the sound as a threat, and respond in a very specific way. “Your brain has the ability to recognize these patterns and assign meaning and remember them,” Dr. Zitelli said. “All your lived experience and everything you know about the world and how it works will contribute and shape how your brain reacts to things.”
Furthermore, your reaction to a sound will depend on the context in which you hear it. Dr. Zitelli gave the example of checking into a hotel room at the end of a long day of travel. The hotel employee tells you that you might hear a hissing because the heating system is under repair. That is good to know, you say, and have a peaceful night’s sleep.
However, instead of the heating system being under repair, what if you are told that a traveling circus is in the area with an escaped cobra? Imagine what kind of night you will have in the dark room by yourself, hearing a hissing sound. Sleep will probably be impossible. Even if you discover the noise is from the heating system, you likely will not be able to relax because somewhere in the back of your brain, you will be afraid of that snake on the loose.
This is because once your brain has determined that something is a threat, or a potential threat, you will have difficulty shifting your attention away from it.
The limbic system generates emotional reactions to sounds and extremely negative reactions to others. A particular sound might make you feel happy, or perhaps it makes you anxious. When your brain generates a negative emotional reaction to something, it sends a signal to your autonomic nervous system that you need to prepare your body physically to respond or remove yourself in some way. You may exhibit a variety of different responses to threats and perceived threats.
This is when trauma responses come into play, like freeze, fight, flop, flight, and fawn. When someone experiences a negative reaction to a sound in their environment, they aren’t just “annoyed.”
Diagnosis
How is DST diagnosed? The process is a little murky as there is not really a consensus among experts about the best way to diagnose. General things typically included in the process are loudness discomfort levels, or LDLs. You may be put in a test booth and asked to judge the loudness of different sounds on a scale of 1 to 7, with 7 being uncomfortably loud, and 1 being very soft. The sound is repeated at different loudness levels until you say 7. You have full control over this test.
You will also likely be asked to fill out a questionnaire asking about the impact of sound on your life. Is it preventing you from going places? How is it limiting you?
It is common to sit down with an audiologist for a consultation related to this for two hours at a time, because there are several components to the process that provide important information.
Hyperacusis
There are two main categories of DST: hyperacusis and misophonia. Hyperacusis characteristics include:
- Abnormally strong reaction to sounds in the auditory pathway
- Manifests as physical discomfort
- Strength of reaction controlled by physical characteristics of sound (no matter who is making the sound or where they are or what they’re doing, if you hear something exceeding a specific loudness level, you will have a reaction to it)
Women tend to have hyperacusis at a higher rate than men, with 0.2-17.2% of the general population experiencing it. People in specific occupations like musicians, music students, and teachers, comprise 3.8-67% of people with the condition. People with specific comorbid conditions (hearing loss, tinnitus, autism) make up 4.7-95% of people with hyperacusis.
Hyperacusis may be linked to other diseases or medical conditions, like autism spectrum, myasthenia gravis, fibromyalgia, and Lyme disease.
There are four types of hyperacusis: loudness, fear, annoyance, and pain. With loudness, sounds are perceived as uncomfortably loud, and emotions are not necessarily triggered. With the fear type, sounds are bothersome, and the stress response is related to anticipation of sounds. With annoyance, emotional reactions are primary, and anxiety, irritation, and stress are common. Pain involves damage to specific cells in the inner ear that may activate pain receptors in the brainstem.
Misophonia
Characteristics of misophonia include abnormally strong reactions of the autonomic and limbic systems, which manifests as negative attitude to sound. The strength of the reaction is controlled by previous experiences and contexts. Individuals with misophonia are often sensitive to a specific set of (not always loud) triggering sounds, like food chewing, gum popping, food crunching, sniffling, breathing, pen clicking, clock ticking, whistling, lip smacking, or finger/foot tapping. It can become a visual trigger as well, even if sound is not occurring.
People with misophonia often display a specific set of criteria. They may feel anxiety, distress, anger, or disgust. Physically, they may have pain/tightness in the chest/arms/head/body, increased muscular tone, or diaphoresis/dyspnea, tachycardia, or hypertension. They know that their reactions are disproportionate and that most people consider these sounds to be irrelevant. The condition affects them at school, work, family, and socially.
Dr. Zitelli shared the words of someone with DST: “Fear can paralyze us, or it can be a catalyst for making change. Four months after I developed hyperacusis, I woke up one morning and realized as much as I missed experiencing sound the way I used to, I missed myself even more.”
Management
DST can be managed effectively for many people. A consultation will likely include an interview, questionnaires, testing, needs assessment/goal setting, counseling, discussion about earplugs/muffs, and a discussion about on-ear devices, other recommendations for self-care and interdisciplinary care. Dr. Zitelli said they work very closely with their colleagues in the mental health field, as there is a lot of overlap.
There are a few treatments for DST. DST-Specific Directive Counseling involves safe and healthy sound exposure to reduce and end reliance on hearing protective devices. Cognitive Behavioral Therapy helps modify dysfunctional cognitions, negative thoughts, and avoidance-seeking behaviors. Sound therapy uses low-level broadband noise from bilateral sound generators – portable and consistent exposure.
In addition to counseling and sound therapy approaches, there are four protocols for managing misophonia. They are designed to move individuals with misophonia toward higher levels of sound tolerance and acceptance of lower levels of controls of sounds.
Challenges
Clinical management of DST has its challenges, like many clinicians lacking training. The condition can also be confused easily. There are no clear standards for managing these conditions, and many audiologists do not have access to the interdisciplinary care providers they need.
In Pittsburgh, there are two clinicians in the Oakland office who can help with DST, but this number will grow with expansion to satellite locations.
Dr. Zitelli shared another quote from someone with DST: “For the first few months, hyperacusis defined me. But I found it was possible, indeed essential, to take hold of a few things in my life that were meaningful to me and get busy pursuing them. None of this came easily or quickly.”
Hearing protection can be a hindrance if not used appropriately, Dr. Zitelli warned. It is more of a band aid than a long-term solution.
A vicious cycle, for example, is when sounds are very bothersome, earplugs are used to reduce the loudness of sounds. But earplugs are not enough, so earmuffs are worn on top. Dual protection is not sufficient, so the person becomes a recluse. Sometimes overprotecting your hearing can make you more sensitive. So, sounds become even more bothersome, and the cycle continues. “Avoiding overuse is really the key,” Dr. Zitelli said.
One last quote from someone with DST was shared: “I have come a long way in re-establishing my sound tolerance. There are many activities in which I can engage that I never imagined I would be able to do again…I function normally, comfortably, Nand with pleasure in aural settings.”
Contact
UPMC audiologists specialize in evaluating and treating DST. “Please do not hesitate to reach out to the UPMC Department of Audiology if you want to discuss options for management of DST,” Dr Zitelli said. “We will be glad to meet with you.”
Call the Audiology center at 412-647-2030 to schedule an appointment.