Noise trauma (synonyms: acoustic trauma; acoustic trauma; hearing loss due to noise; noise effect on inner ear; noise-induced hearing loss; noise-induced deafness; acoustic trauma; noise-induced hearing loss; noise-induced deafness; noise-induced hearing loss; noise damage to the inner ear; ICD-10-GM H: 83.3: Noise-induced hearing loss of the inner ear) involves damage to the middle and/or inner ear, which may have been induced directly or indirectly.
The following forms can be distinguished:
- Acute noise trauma – loudness is usually > 120 dB or 90-120 dB with concomitant reduced perfusion (reduced blood flow) to the ear; lasts from minutes to several hours; visits to discotheques/concerts, low-flying aircraft as well as fireworks lead to such noise exposure; the inner ear is damaged
- Chronic noise trauma (noise-induced hearing loss) – occupational disease caused by years of exposure to noise levels of ≥ 85 dB; suspicion is reportable
- Blast trauma – at a sound pressure wave 1-2 msec; volume level > 140 dB; e.g., shots fired nearby, bursting airbags, exploding firecrackers; acute damage to the hair cells of the organ of Corti of the inner ear Explosion trauma – at a sound pressure wave > 2 msec; damage to the sensory cells, often the eardrum is also injured, it comes to a conductive hearing loss
- Blunt head trauma with labyrinth concussion.
In noise trauma, in contrast to the blast trauma, both ears are usually affected.
Sex ratio: The acute noise trauma caused by New Year’s Eve firecrackers: men to women is 3: 1.
Frequency peak: The acute noise trauma caused by New Year’s Eve firecrackers occurs predominantly in adolescents.
The prevalence (frequency of illness) is 0.05% (in Germany).
The incidence (frequency of new cases) of acute noise trauma caused by New Year’s Eve firecrackers is approximately 28-107 cases per 100,000 inhabitants per year (in Germany).
Course and prognosis: If the noise trauma is unique, e.g. caused by a visit to a very loud concert, the resulting metabolic disturbance of the sensory cells of the hearing organ (“cochlea”) located in the inner ear is reversible. However, if the noise exposure is frequent or chronic, the dysfunction is permanent. Noise trauma is often accompanied by tinnitus (ringing in the ears). Many of those affected also complain of hypacusis (hearing loss). Both tinnitus and hypacusis begin immediately after the noise event, but usually resolve over time. The ear may take up to several weeks to fully recover. Chronic noise trauma is non-progressive (progressive). In the case of acoustic trauma, symptoms improve within the first few days. Progression of the disease does not usually occur. In the setting of blast trauma, progression of hypacusis is possible.