Extended high‐frequency audiometry in patients with acoustic trauma

OBJECTIVES: The aim of this study was to examine extended high-frequency (EHF) hearing in patients with acoustic trauma. DESIGN: A prospective, case-control study in a group of soldiers with acoustic trauma caused by shooting practice during basic training. SETTING: Tertiary referral centre. PARTICIPANTS: A total of 39 young soldiers hospitalized for hearing loss and tinnitus following exposure to weapon impulse noise were studied. Conventional audiometry in the frequency range 0.25-8 kHz and EHF audiometry in the frequency range 9-20 kHz were performed, both on admittance and before discharge. Thirty healthy recruits of similar age and sex were used as controls. MAIN OUTCOME MEASURES: Pure-tone threshold changes documented by conventional and EHF audiometry. RESULTS: The most significant differences in pure-tone thresholds on initial testing were found in the frequency range 0.25-11.2 kHz, and especially in the 4-8 kHz region. Reduction in thresholds across most frequencies was observed after treatment, although recovery was partial in most cases. CONCLUSIONS: The EHF audiometry adds no significant additional information to conventional pure-tone audiometry in assessing and monitoring noise-induced hearing loss.