Hojok

Also known as the taepyongso (tae-pyong-so, "big peace wind instrument"), the hojok is a Korean wind instrument that falls into the oboe family. The hojok usually has a conical wooden body with a metal mouthpiece and bell, although some are made entirely of metal.

The loud and piercing sound it produces has kept it confined mostly to Korean folk music (especially "farmer's band music") and marching bands.

Probably derived from a Chinese instrument like the sona.