목적: Though acoustic trauma is often accompanied by hearing loss (HL), sometimes tinnitus without subjective HL could be the sole symptom of acoustic trauma. We aimed to compare the clinical characteristics and treatment outcome of intratympanic dexamethasone (ITD) between acute noise-induced tinnitus and acute idiopathic tinnitus. 방법:The subjects included 20 subjects who were treated with ITD for acute tinnitus developed immediately after noise-exposure and unaccompanied by HL which meets the criteria for sudden sensorineural HL. As a control, 39 subjects who were treated with ITD for acute idiopathic tinnitus (< 3 months) were enrolled. The treatment outcome was measured by the comparisons of the initial and final follow-up questionnaires, and mean durations of questionnaires follow-up in noise-induced group and idiopathic group were 75.9 ± 69.8 weeks and 93.4 ± 101.4 weeks respectively (p > 0.05). 결과:Compared to acute idiopathic tinnitus, acute noise-induced tinnitus were found in younger age (38.3 ± 18.3 vs. 53.6 ± 14.1, p = 0.00) and showed a predominance of males (M:F 13:7 vs. M:F 13:26, p = 0.02). Asymmetric/symmetric hearing ratio of both group were 12:8 and 21:18, respectively (p > 0.05). In the noise-induced tinnitus group, the cure rate was 10% (2/20) and the improvement rate was 25% (5/20), and idiopathic tinnitus group showed 25.6% (10/39) cure rate and 35.9% (14/39) improvement rate. There were no differences in the cure/improvement rate between both groups (p > 0.05). There were no differences in pre- and post-treatment changes in mean tinnitus loudness (-1.4 ± 2.0 vs. -1.8 ± 2.5 / 10 points), mean tinnitus awareness duration (-29.5 ± 36.6 % vs.-30.8 ± 33.9%) and mean handicap inventory score (-17.1 ± 21.0 vs. -15.6 ± 20.2 / 100 points) between both groups (p > 0.05). 결론:Acute noise-induced tinnitus occurs frequently in young male adults, and the treatment outcome with ITD was not different from that of acute idiopathic tinnitus.