Like many who suffer from a rare disorder, hyperacusis sufferers frequently face clinicians who have an insufficient understanding of the most impacting characteristics of the condition. Expanding disorder definitions to include new markers takes significant time and evidence. Subtyping can help provide a path to distinguishing important features. Hyperacusis is categorized into four subtypes: loudness, pain, annoyance, and fear.1 This differentiates two physically and two emotionally based components of the condition. This distinction represented an important step forward for clinicians to assess these subtypes—especially to determine whether it's the loudness of everyday sounds or the pain induced by those sounds that has the most impact on the patient. A small but growing body of hyperacusis publications now include pain in the discussion (with 39 articles found in a recent PubMed search).
The wide array of definitions has made establishing prevalence of hyperacusis challenging. In the 2014 National Health Interview Survey,2 5.9 percent of respondents had sensitivity to everyday sounds as determined by the question, “Do everyday sounds, such as from a hair dryer, vacuum cleaner, lawnmower, or siren, seem too loud or annoying to you?” This question applied to all who are more broadly described as having decreased sound tolerance. In a recent paper on decreased sound tolerance associated with blast exposure, Theodoroff, et al.,3 found that irrespective of blast exposure, 29 percent (53 of 181) of military service members and 40 percent (99 of 245) of U.S. military veterans reported some degree of decreased sound tolerance. These findings highlighted the need for better methods to screen for hyperacusis, and identify complaints of decreased sound tolerance as part of audiological evaluations.
One of our aims at Hyperacusis Research Limited, Inc., is to identify key characteristics of hyperacusis to support basic scientific and clinical research. In 2015, a comprehensive registry of people with hyperacusis was initiated with the Coordination of Rare Diseases at Sanford (CoRDS) Registry. Over 200 patients have registered for the 98-question survey. While the anonymized data is available to any interested research institution, we have performed a preliminary analysis that has shown critical insights. Our findings highlight important areas for audiologists to assess when evaluating patients for hyperacusis.
SURVEYS ON HYPERACUSIS COMPLAINTS
Several factors must be considered about the applicability of the Sanford dataset to the hyperacusis population at large due to the extensive nature of the registration process and length of the survey. The effort required to complete the survey could bias the results toward worse case sufferers. Over the past few years, we have determined several characteristics that need closer investigation. We also wanted to hear more from the patients using open-ended questions. Therefore, we initiated a new survey to get insights beyond the Sanford registry and potentially shed light on whether the Sanford findings can be broadly applied.
To ensure a wide range of patients, we recruited participants on six social media platforms, including those oriented toward tinnitus, considering the fact that about 30 to 40 percent of tinnitus sufferers have hyperacusis.4 We streamlined the survey design, limited it to 30 questions (which took an average of 11 minutes to complete), and included some questions from the Sanford registry to allow crossover analysis. Since June 2019, over 350 participants have completed the new survey.
A leading question in the new survey asked participants to select up to three primary complaints related to hyperacusis. While the complaint list included 14 items, three complaints stood out: ear pain caused by sound, loudness sensation, and increased tinnitus from sound. With this rank order, we suspected that pain from sound is likely more prevalent in the hyperacusis population than previously assumed. Aural fullness and a thumping or fluttering sensation in the ear were also highly ranked.
A question related to hyperacusis symmetry was: “Would you say that you experience your hyperacusis symptoms equally in each ear?” A similar question was also asked in the Sanford survey. The results of both surveys (see Fig.1) were statistically matched, which revealed that about half indicated having symptom differences between ears.
Following this question, participants were asked: “On a scale of 0 to 10, how would you rate your level of symptom severity in each ear?” (with 0 for no symptoms and 10 for severe pain or major life impact), and 41 percent rated each ear differently for symptom level. The delta between ears averaged a dramatic 4.6 difference. An open question also asked participants to describe the differences in sensation that they experience between ears. A word analysis demonstrated that ear pain differences were the most common, followed by loudness sensation, tinnitus, and ear fullness.
Additionally, most participants had an explanation for symptom differences between the ears. Most frequently, the initial injury was known to be one-sided, such as with a gun shot or a loud noise on one side. These findings are extremely important since hyperacusis has been considered as typically bilateral. But with many sufferers experiencing symptom differences between ears, the exact role of the central gain model and the hypothesis that various auditory pathways within the brain are primarily responsible for patients’ symptoms need to be examined more thoroughly.
FOCUS ON PAIN AND SETBACKS
On the topic of pain, 92 percent of the 2019 survey respondents said that sounds caused pain or physical discomfort. This number was well matched to the Sanford survey at 91 percent. Additional details from the Sanford survey showed that 62 percent of respondents experienced ear pain at least daily, and 75 percent indicated the ear pain was a result of being exposed to new loud noises. Once initiated, the pain cycle lasted weeks or longer for 28 percent of the respondents, and several days for 18 percent. Responses about the type of pain patients experienced (e.g., dull ache, burning, sharp, stabbing pain, and throbbing pain) were evenly distributed.
A key focus of the 2019 survey (also briefly covered in the Sanford survey) was what patients refer to as a setback. Both surveys asked participants how often they experienced setbacks that made their condition worse. About 37 percent of Sanford survey respondents and 50 percent of the 2019 survey respondents reported having setbacks at least weekly. In the 2019 survey, a critical question related to setbacks was: “Think about your worst setback—what impact did it have?” Fifty-four percent indicated their setback made their condition worse than ever, and 43 percent said they usually needed a few weeks to a few months to recover from these setbacks. These results were like those of the Sanford survey. Notably, 14 percent of the 2019 survey respondents said they never fully recovered. This population represents the most challenging and most overlooked group of hyperacusis sufferers.
Setback prevention is a key focus for many hyperacusis sufferers. In the new survey, we asked: “Describe the actions you take to prevent setbacks.” A word cloud, shown in Figure 2, was generated from the responses.
Avoiding loud sounds was the most common response, followed by wearing earplugs. The responses were logical, given that loud sounds were the main cause of setbacks. A clinically focused question asked: “If you have had a clinical evaluation for your hyperacusis, did the clinician ask you any question related to setbacks?” Only 29 percent reported that the topic of setbacks was covered by their clinician.
These results represent critical components that need to be comprehended in clinical evaluations. A patient's history of setbacks should be considered when determining the best treatment approach and expected outcome. Many patients will likely rank setback prevention and reduction of pain symptoms as their top priorities. For some, perceiving sounds as excessively loud may be a low priority.
In summary, the new 2019 brief hyperacusis survey reinforces the primary findings of the extensive Sanford registry. Both surveys suggest that hyperacusis with pain is common among hyperacusis sufferers. Also, many sufferers experience setbacks that temporarily or permanently make their symptoms worse. Therefore, setback prevention should be a top priority of clinical treatment programs. Opportunities also exist for researchers to study the physiological mechanism for setbacks and determine what inhibits or enables a quicker recovery. With a better understanding of these key characteristics of hyperacusis patients, a path will emerge to create a better future for them.
1. Tyler RS, Pienkowski M, Roncancio ER, Jun HJ, Brozoski T, Dauman N, Dauman N, Andersson G, Keiner AJ, Cacace AT, Martin N, Moore BC A Review of Hyperacusis and Future Directions: Part I. Definitions and Manifestations. American Journal of Audiology. 2014. 23. 10.1044/2014_AJA-14-0010.
3. M. Theodoroff, Sarah & M. Reavis, Kelly & Griest, Susan & Carlson, Kathleen & L. Hammill, Tanisha & A. Henry, James. (2019). Decreased sound tolerance associated with blast exposure. Scientific Reports. 9. 10.1038/s41598-019-46626-6.
4. Sheldrake J, Diehl PU, Schaette R Audiometric characteristics of hyperacusis patients. Front Neurol. 2015;6:105. Published 2015 May 15. doi:10.3389/fneur.2015.00105.