Understanding hyperacusis: Insights into conditions of reduced sound tolerance

By gaining a better understanding of hyperacusis, you can help reduce its impact and improve the well-being of your patients. Dr. Dany Pineault, Academic and Clinical Audiologist, shares what we know about these conditions and how you can help.

Hearing care professionals (HCPs) have been trained to support patients struggling with sounds being too soft as often experienced with elevated hearing thresholds and ringing in the ears. However, in recent years, clinicians have noticed an increase in patients seeking audiological services for sounds being too loud. Although experts at treating hearing loss, many HCPs do not feel knowledgeable enough to provide care to patients with decreased sound tolerance (DST).

Although hyperacusis can occur in isolation, it is most often associated with tinnitus and hearing loss.1-3 Undiagnosed sound tolerance disturbances can seriously compromise hearing aid intervention outcomes, reduce satisfaction and safety with services received. Considering the far-reaching impact of DST on hearing health and rehabilitative effort, it is critical for clinicians to better understand hyperacusis in terms of clinical manifestations, assessment guidelines, and management strategies.

Definition and classification systems

In broad terms, hyperacusis is a heightened awareness and increased sensitivity to everyday sounds.1,2,4 While these ordinary environmental sounds are of normal loudness to most people, they may be perceived as uncomfortably loud and trigger abnormal responses such as fear, annoyance, and pain for patients with hyperacusis.

Although the nature of these distressing sounds varies among patients, moderately intense sounds from the kitchen, bathroom, large gatherings, sporting events, construction sites and sirens of emergency vehicles are common offenders.

Did you know that peak sound levels as high as 107 dB SPL have been measured when simply dropping a spoon in a bowl?5 No wonder kitchen noises are as big a source of irritation and distress for patients with DST.

The prevalence of hyperacusis is conservatively estimated at 2% of the general population.1,2 However, epidemiological studies conducted on different aspects of DST point to a much higher value. In 2004, Jastreboff & Hazell proposed a classification system based on different forms of sound sensitivities often encountered among patients with tinnitus and hearing loss.3

DST was used as an umbrella term for hyperacusis (i.e., discomfort with moderate and loud sounds), misophonia (i.e., dislike/aversion to soft human-made sounds such as chewing) and phonophobia (i.e., fear of certain sounds). Ten years later, Tyler and colleagues added a category for the experience of pain associated with moderate to moderately intense sound.4 They proposed the following four categories: loudness hyperacusis, annoyance hyperacusis (misophonia), fear hyperacusis (phonophobia) and pain hyperacusis.

Although misophonia and phonophobia can both be incapacitating, this article focuses on loudness hyperacusis comorbid with hearing loss and/or tinnitus. As an aside, loudness hyperacusis is not to be mistaken for recruitment often observed among patients with damaged cochleae. Recruitment is believed to be an abnormally rapid growth in perceived loudness with increasing sound intensity.6

Clinical manifestations, etiology, and neural mechanisms

Most patients report a sudden onset of hyperacusis. Although unilateral cases have been reported, most patients present with reduced loudness discomfort levels (LDLs) in both ears. The audiometric configurations of hyperacusis-related changes in loudness perception can be equal across the frequency range or more pronounced on the high frequencies.2,7

Hyperacusis is triggered by a variety of health problems. Table 1 shows a list of conditions and disorders often linked with the development of hyperacusis among adults and children.1,3,4,7 Hyperacusis is often experienced with hearing loss.1,2,8

Table 1: Lists of conditions and disorders often associated with the development of hyperacusis.

It is estimated that up to 50% of patients present elevated high-frequency thresholds. But the relationship is complex as patients can also display hearing thresholds within the normal range. Therefore, the concept of hidden hearing loss was proposed to explain the development of hyperacusis among these patients.9

Based on their animal studies, Kujawa and Liberman (2009) hypothesized that overexposure to intensely loud sounds could also result in cochlear nerve degeneration without hair cell damage (i.e., cochlear synaptopathy) in human ears that is similar to mice.10 Hyperacusis is also significantly associated with tinnitus. It is estimated that up to 80% of patients also experience tinnitus. Moreover, 40% of patients with tinnitus also show symptoms of hyperacusis. Although both hearing problems seem to share a similar course of development, researchers believe different neural mechanisms may be responsible for their onset.11

Finally, hyperacusis is linked to poor levels of well-being.12,13 Adults with hyperacusis are more likely than adults without the symptom to report high-level of daily stress, anxiety and depression.14,15 Maladaptive coping strategies such as avoidance of public places and excessive use of hearing protection devices are often reported in an attempt to lessen the distress associated with DST.1,3,16

Although the exact physiological mechanisms underlying the development of hyperacusis remains to be confirmed, researchers point to excessive central gain (hyperactivity) in the auditory pathways.17, 18 A functional MRI study conducted among subjects with and without DST has found elevated sound-evoked activity in the inferior colliculus, medial geniculate body and primary auditory cortex among subjects with hyperacusis when exposed to noise delivered at different intensities.19

Guidelines for hyperacusis assessment

A comprehensive case history is needed to access critical information about events surrounding:

  • onset of hyperacusis (e.g., following noise exposure, head injury, stapedectomy);
  • detailed inventory of offending sounds (e.g., kitchen sounds, emergency vehicles, breathing/eating sounds);
  • specific reactions experienced with DST (e.g., discomfort, pain, annoyance, fear);
  • associated hearing problems (e.g., hearing difficulty, trouble understanding speech-in-noise, tinnitus);
  • change in behaviors (e.g., avoiding loud situations, excessive use of earplugs); and
  • impact on quality of life (e.g., irritability, inability to relax, withdrawing from social interactions, relationship problems, interference with work).20

When hyperacusis is suspected among patients with hearing loss and tinnitus, it is important for HCPs to take precautions with some routine testing procedures (e.g., acoustic reflex) to avoid discomfort and pain. Aazh and Moore found that 21% of patients at a clinic specializing in tinnitus and hyperacusis experienced stimulus level exceeding their LDLs.20

While there is no collective agreement about the best diagnostic procedure for the evaluation of hyperacusis, LDL measurement at 0.5, 1, 2, 4 and 8 kHz remains the most used method worldwide.1,4,7 Patients are asked to make an appraisal of the loudness of sounds heard through the audiometer’s headphones. Starting at a level predicted from the audiogram to be comfortable, tones are presented in 5 dB increments until the patient indicates that sound has reached an uncomfortable loudness level (before any discomfort or pain).

Furthermore, there is no consensus about diagnostic criteria for hyperacusis severity. However, Goldstein and Shulman suggested a classification system based on LDLs obtained at two different frequencies (Table 2).21 They found a positive correlation between hyperacusis and LDL. But the lack of standardized testing protocols and risk of inflicting distress and pain have led to the development of new clinical tools.

Table 2: Classification system for hyperacusis severity based on loudness discomfort level (suggested by Goldstein and Shulman).

Several self-report measures (e.g., Visual Analog Scale (VAS) and Modified Khalfa Hyperacusis Questionnaire) are also recommended for the evaluation of severity and distress associated with hyperacusis.23,24 VAS is the most frequently used method to assess the intensity and frequency of pain (i.e., acute or chronic) due to significant amount of empirical evidence supporting its validity and reliability (Figure 1).24

Figure 1. Visual analog scale (VAS) for loudness hyperacusis.

Finally, as hyperacusis and tinnitus patients are more prone to anxiety and depression, it is critical to screen for emotional disturbances to avoid unsuccessful treatment with hearing aids.25 The screening of mental health conditions is facilitated by the administration of validated self-report measures of emotional disturbances. The Perceived Stress Scale (PSS), Hospital Anxiety and Depression Scale and Patient Health Questionnaire (PHQ-9) are used by many clinicians for its ease of administration.26-28

If a patient scores high on these questionnaires, a referral to a mental health professional for assessment and treatment might take priority over audiological intervention.

Management strategies

There is currently no cure for hyperacusis. However, many audiological management strategies have been found to be effective at reducing its impact and improving quality of life. Indeed, amplification, sound therapy and counseling have been shown to promote a reduction in central gain and consequently expansion of dynamic range.30

Traditionally, the fitting of hearing aids for patients with loudness hyperacusis with an associated hearing loss was contraindicated due to lack of assessment guidelines and hearing aid limitations. However, recent advances in technology make it possible to safely improve a patient’s hearing sensitivity and sound tolerance levels.

Patients with mild and moderate loudness hyperacusis can benefit from using hearing aids equipped with transient noise reduction feature allowing the attenuation of loud household impulse sounds such as dishes clattering and door slamming. Moreover, hearing aids with dynamic noise canceling capabilities can help reduce offending city noises, improve sound comfort level, and preserve speech audibility.

Patients with a more severe degree of hyperacusis may also benefit from hearing aids equipped with therapeutic sound generating capabilities. Continuous low-level white or pink noise can distract and sometimes give patients relief from annoying environmental sounds. Formby and colleagues measured an average of 10 to 12 dB improvement in LDLs after treatment with combination devices.30

But technological intervention alone is not enough. HCPs must take the time to educate patients on the hidden consequences of excessive use of hearing protection devices and avoidance of loud social settings.31 Maladaptive coping strategies have been proven to worsen hyperacusis and distress with symptoms. Clinicians are reminded to always be kind, empathetic, patient, and supportive as it takes time to make positive changes and regain a sense of control with sound tolerance disturbances. Finally, seeking help from mental health professionals specialized in Cognitive Behavioral Therapy may be needed for patients with poor overall well-being.

References

  1. Paulin, J., Andersson, L. & Nordin, S. (2016). Characteristics of hyperacusis in the general population. Noise Health; 18:178-84.
  2. Sheldrake, J., Diehl, P.U. & Schaette, R. (2015). Audiometric characteristics of hyperacusis patients. Front Neurol; 15(6):105.
  3. Jastreboff, P., & Hazell, J. (2004). Tinnitus retraining therapy: Implementing the neurophysiological model. Cambridge: Cambridge University Press.
  4. Tyler, R.S., Pienkowski, M., Roncancio, E.R., Jun, H.J., Brozoski, T., Dauman, N., Coelho, C.B., Anderson, G., Keiner, A.J., Cacace, A.T., Martin, N., & Moore, B.J. (2014). A review of hyperacusis and future directions: Part I. Definitions and manifestations. J Am Acad Audiology.
  5. Teder, H. (2014). Common transient sounds: The kitchen is a very noisy place. Publication of the Canadian Academy of Audiology.
  6. Vernon, J. (1991). Recruitment/when noise spells pain. The Voice; 12:37.
  7. Aazh, H., & Moore, B.C.J. (2018). Prevalence and characteristics of patients with severe hyperacusis among patients seen in a tinnitus and hyperacusis clinic. J Am Acad Audiology; 29(7):626-633.
  8. Tidball, G. (2015). The quick and dirty on hyperacusis. Publication of the Canadian Academy of Audiology.
  9. Le Prell, C.G. (2018). Hidden versus not-so-hidden hearing loss. Publication of the Canadian Academy of Audiology.
  10. Kujawa, S.G. & Liberman, M.C. (2009). Adding Insult to Injury: Cochlear nerve degeneration after “temporary” noise-induced hearing loss. Journal of Neuroscience.
  11. Formby, C., Sherlock, L.P. & Gold, S.L. (2003). Adaptive plasticity of loudness induced by chronic attenuation and enhancement of the acoustic background. J Acoust Soc Am.
  12. Pineault, D. (2021). Impact of COVID-19 pandemic on mental health and people with hearing problems, The Hearing Journal; 74(3):6.
  13. Canlon, B., Theorell, T., & Hasson, D. (2013). Associations between stress and hearing problems in humans. Hear Res; 295:9-15.
  14. Hasson, D., Theorell, T., Bergquist, J. & Canlon, B. (2013). Acute stress induces hyperacusis in women with high levels of emotional exhaustion. PLoS One; 8(1):e52945.
  15. Jüris, L., Andersson, G., Larsen, H.C. & Ekselius, L. (2013). Psychiatric comorbidity and personality traits in patients with hyperacusis. Int J Audiol; 52(4):230-5.
  16. Blaesing, L. & Kroener-Herwing, B. (2012). Self-reported and behavioral sound avoidance in tinnitus and hyperacusis subjects, and association with anxiety ratings. International Journal of Audiology.
  17. Auerbach, B.D., Rodrigues, P.V., & Salvi, R.J. (2014). Central gain control in tinnitus and hyperacusis. Front Neurol; 24(5):206.
  18. Salvi, R.J., Wang, J. & Ding, D. (2000). Auditory plasticity and hyperactivity following cochlear damage. Hear Res; 147: 261–274.
  19. Gu, J.W., Halpin, C.F., Nam, E.C., Levine, R.A. & Melcher, J.R. (2010). Tinnitus, diminished sound-level tolerance, and elevated auditory activity in humans with clinically normal hearing sensitivity. J Neurophysiol; 104(6):3361-70.
  20. Pineault, D. (2020, September 24). Assessing and managing COVID-19 related tinnitus. Phonak Audiology Blog [Clinical Practice]. Retrieved from https://audiologyblog.phonakpro.com/assessing-and-managing-covid-19-related-tinnitus/
  21. Aazh H., & Moore, B.C.I. (2017). Incidence of discomfort during pure-tone audiometry and measurement of uncomfortable loudness levels among people seeking help for tinnitus and/or hyperacusis. American Journal of Audiology; 26:226–232.
  22. Goldstein, B. & Shulman, A. (1996). Tinnitus-hyperacusis and loudness discomfort level test – a preliminary report. International Tinnitus Journal; 2:83-89.
  23. Khalfa, S., Dubal, S., Jouvent, R., et al. (2002). Psychometric normalization of a hyperacusis questionnaire. ORL J Otorhinolaryngol Relat Spec ; 64:436-42.
  24. Boonstra, A.M., Schiphorst Preuper, H.R., Reneman, M.F., Posthumus, J.B. & Stewart, R.E. (2008). Reliability and validity of the visual analogue scale for disability in patients with chronic musculoskeletal pain. Int J Rehabil Res; 31(2):165-9. 
  25. Lin, C.E., Chen, L.F., Chou, P.H. & Chung, C.H. (2018). Increased prevalence and risk of anxiety disorders in adults with tinnitus: a population-based study in Taiwan. General Hospital Psychiatry; 131-136.
  26. de Klaver, M.J., van Rijn, M.A., Marinus, J., Soede, W., de Laat, J.A. & van Hilten, J.J. (2017). Hyperacusis in patients with complex regional pain syndrome related dystonia. J Neurol Neurosurg Psychiatry; 78(12):1310-3.
  27. Cohen, S., Kamarck, T., Mermelstein, R. (1983). A global measure of perceived stress. J Health Soc Behav; 24(4):385-96.
  28. Zigmond, A.S. & Snaith, R.P. (1983). The hospital anxiety and depression scale. Acta Psychiatr Scand; 67(6):361-70.
  29. Kroenke, K., Spitzer, R.L. & Williams, J.B. (2001). The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med; 16(9):606-13.
  30. Formby, C., Hawley, M.L., Sherlock, L.P., Gold, S., Payne, J., Brooks, R., Parton, J.M., Juneau, R., Desporte, E.J. & Siegle, G.R. (2015). A sound therapy-based intervention to expand the auditory dynamic range for loudness among persons with sensorineural hearing losses: A randomized placebo-controlled clinical trial. Semin Hear;36(2):77-110.
  31. Budd, R.J. & Pugh, R. (1996). Tinnitus coping style and its relationship to tinnitus severity and emotional distress. J Psychosom Res; 41(4):327-35.