Sudden Hearing Loss

Last updated May 3, 2022

Key Points

Key Points

  • Sudden hearing loss (SHL) is a frightening symptom that often prompts an urgent or emergent visit to a clinician. This guideline update focuses on sudden sensorineural hearing loss (SSNHL), the majority of which is idiopathic and which, if not recognized and managed promptly, may result in persistent hearing loss and tinnitus and reduced patient quality of life (QOL). SSNHL affects 5–27 per 100,000 people annually, with about 66,000 new cases per year in the United States.
  • SHL is defined as a rapid-onset subjective sensation of hearing impairment in one or both ears. The hearing loss in SHL may be conductive (CHL), sensorineural (SNHL), or mixed (MHL), defined as both CHL and SNHL occurring in the same ear. CHL and the conductive component of MHL may be due to an abnormality in the ear canal, tympanic membrane (‘ear drum’), or middle ear.
    • Physical examination will help determine if there is obstructing cerumen or a foreign body in the ear canal, if there is a perforation of the tympanic membrane, or if there is fluid in the middle ear.
    • Tuning fork testing will enable the initial treating clinician to distinguish CHL from SNHL, so that the SSNHL evaluation and management (E&M) pathway can be triggered appropriately.
  • SSNHL is a subset of SHL that is: a) sensorineural in nature, b) occurs within a 72-hour window, and c) meets certain audiometric criteria.
    • SNHL is sometimes referred to colloquially as ‘nerve hearing loss’ and indicates abnormal functioning of the cochlea, auditory nerve, or higher aspects of central auditory perception or processing.
    • The most frequently used audiometric criterion for SSNHL is a decrease in hearing of greater than or equal to 30 decibels affecting at least 3 consecutive frequencies. Because premorbid audiometry is generally unavailable, hearing loss is often defined in relation to the opposite ear’s thresholds.
    • The CPG update group acknowledges that in both clinical practice and in research studies, less stringent criteria for SSNHL are employed.
    • SSNHL is often but not always accompanied by tinnitus and/or vertigo. The tinnitus may persist and may be disturbing to the patient.
  • Idiopathic sudden sensorineural hearing loss (ISSNHL) is defined as SSNHL with no identifiable cause despite adequate investigation. This is the situation in 90% of patients with SSNHL and is the primary focus of this CPG update. The use of SSNHL in this document refers to ISSNHL, after the appropriate workup has been done as denoted in KAS 1 and KAS 2.

Table 1. Definitions of Common Terminology

Sudden Hearing Loss (SHL) A rapid-onset subjective sensation of hearing impairment in one or both ears.
Sensorineural Hearing Loss (SNHL) Hearing loss resulting from abnormal function of the cochlea, auditory nerve, or higher aspects of central auditory perception or processing.
Conductive Hearing Loss (CHL) Hearing loss resulting from a problem conducting sound waves anywhere along the route through the outer ear, tympanic membrane, or middle ear.
Mixed Hearing Loss (MHL) Hearing loss resulting from both SNHL and CHL occurring in the same ear.
Sudden Sensorineural Hearing Loss (SSNHL) A subset of SHL that is a) sensorineural in nature, b) occurs within a 72-hour window, and c) consists of a decrease in hearing of greater than or equal to 30 decibels affecting at least 3 consecutive frequencies.
Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL) SSNHL with no identifiable cause despite adequate investigation.
Salvage Therapy Any therapy offered after 2 weeks from symptom onset (even if initial therapy was observation).

Summary of Key Action Statements (KAS)

...Summary of Key...

...f CHLClinicians should distinguish SNHL from C...


...odifying factorsClinicians should assess pati...


...d tomography (CT)Clinicians should NOT order r...


Audiometric confirmation of SSNHLIn patients wi...


...ngClinicians should NOT obtain routin...


...athologyClinicians should evaluate...


...tionClinicians should educate patients with...


...corticosteroidsClinicians may offer cortic...


...nitial therapy with hyperbaric oxygen the...


...ge therapy with HBOTClinicians may...


...ympanic steroids for salvage therap...


...ther pharmacologic therapyClinicians shoul...


...essmentClinicians should obtain follow-up aud...


...abilitationClinicians should counsel patie...


Diagnosis

...Diagnosis

The distinction between SSNHL and o...


...Figure 1....


...ended Technique for Weber and Rinne T...


Table 4. Some Symptoms and Signs Suggestive of No...


...5. Selected Conditions That May Be Asso...


Treatment

...Trea...

...ble 6. General Guidelines for Cortico...


...able 7. Common Issues Raised by Individua...


Patient Information

...Patient Informatio...

...to Ask Your Provider About Sudden Sensorineur...


...sorineural Hearing Loss (SSNHL) Frequently A...