Abstract
Objective : We used audiometry and follow-up examinations in male university students to investigate whether kendo (Japanese fencing with bamboo swords) has an effect on hearing in kendo practitioners.
Materials and methods : We conducted audiometry for 237 male university students (117 kendo practitioners and 120 non-practitioners), and followed up for two years with audiometry and a distortion-product otoacoustic emission (DPOAE) test for 13 kendo practitioners.
Results : Only four out of 120 non-practitioner male students had hearing deficits, but 32 out of 117 male kendo practitioners showed deficits. The hearing deficits of the practitioners showed a wide range from 0.5 to 8 kHz, and many of the audiograms indicated frequency-hearing deficits at 2 or more frequencies. Testing showed a significant deficit in kendo practitioners at 0.5, 1 and 2 kHz, according to the follow-up DPOAE testing. In addition, according to audiograms and DPOAE test results, hearing decreased significantly in practitioners at 3, 4, 5 and 6 kHz.
Conclusions : Our audiometry results suggested that kendo practice has a negative influence on hearing. Long-term kendo practice showed a stronger effect in the frequency range from 1 kHz to 4 kHz. However, we found that the negative impacts could possibly be reduced with consideration of the spatial and environmental conditions of the practice room. Moreover, our findings suggested that the DPOAE test may be useful as an index for evaluation in the early stages of hearing change.
