Absolute Indications For Audiogram (Hearing Test)

All patients with subjective hearing loss and tinnitus following blast exposure should have the exposure documented and should be evaluated by hearing testing as soon as possible. Hearing loss and associated acoustic trauma symptoms are detrimental to the patient’s personal safety, quality of life, and medical readiness. Patients should be referred to ENT for evaluation and further testing. If audiometry or ENT care is not available, patients should be evacuated to a higher level of care.

Hearing loss (either subjective or documented through an air conduction audiogram) that persists for more than 72 hours after an acoustic trauma or blast injury warrants a comprehensive hearing test or audiogram (including tympanometry, bone conducted thresholds, speech discrimination, and acoustic reflexes). A screening audiogram is not sufficient. Patients with temporary threshold shift (TTS) greater than 25 dB losses in three consecutive frequencies should be considered candidates for high dose oral and/or transtympanic steroid injections when not otherwise contraindicated. An oral steroid regimen of prednisone 60mg daily for 10 days could be considered for TTS less than 25 dB loss in three consecutive frequencies at the discretion of the treating provider, as the risks associated with oral steroids are low and not otherwise contraindicated. Within 2-6 weeks of hearing loss, initiate 3 injections within a 10-day period of transtympanic dexamethasone (10mg/ml or 24mg/ml) as a salvage to oral steroids. Hyperbaric oxygen therapy is also an option if available and not contraindicated. Hearing response to treatment should be followed by audiometry within 2 weeks of completing therapy and 6 months following therapy.28 Patients with threshold shift greater than 60 dB on three consecutive frequencies for ten or more days after noise exposure are not likely to resolve spontaneously and the hearing loss is likely permanent.