yes. it is onomatopoeia. That sound can be heard when you open an old door. A. B... we should not make any sound. open that door with silence. B. okey. (찌그덕! 찌그덕!) police. FREEZE! POLICE! A.너 왜 소리냈어. B.문이 오래되서 찌그덕 소리가 나버렸네.