Acute Low-Tone (Frequency) Hearing Loss

Abstract

Acute low-tone hearing loss (ALHL) or acute low-frequency hearing loss is classified as a subset of idiopathic sudden sensorineural hearing loss. The patients with ALHL tend to complain of ear fullness, tinnitus, and low tone hearing changes, rather than severe hearing loss and vertigo. Diagnostic criteria for ALHL comprise a mean hearing loss of at least 30 dB at three low frequencies (125, 250, and 500 Hz) and a mean hearing loss of 20 dB or less at three high frequencies (2, 4, and 8 kHz). ALHL is presumed to be an early stage of Meniere’s disease, because symptoms such as ear fullness, low-tone hearing loss, tinnitus, and occasional vertigo are similar between the two diseases. Progress of ALHL can be evaluated using pure tone audiometry, electro-cochloegraphy, vestibular evoked myogenic potential, and Caloric test. Patients with ALHL recovered from initial hearing loss after diuretics and full dose of steroid therapy, and the majority of hearing loss significantly recovered (more than 10 dB recovery in 83.9% of patients; 62.9%-91.3% recovery rate). The recurrence rate of hearing loss reaches 50% over 5 years, and the transition to Meniere’s disease also reaches 15.6% (10%- 24%). A low-sodium diet and plant-based diet are recommended in parallel with drug treatment. ALHL can be a common type of metabolic disease in modern civilization, and additional research will be needed.