You gotta make sure you're playing the game right. You don't want something to be unbalanced and keep using it if it's been fixed. That's why you need to check out the updated Bolt Action FAQ that Warlord Games has posted. They've also put up an article based on their Korean variety of the game, adding in instruments to the Chinese army (it'll make more sense when you read the article).
We present the latest FAQ for Bolt Action. This PDF is the most up to date source for rulings and replaces any previous documents.
When the Chinese entered the Korean conflict, they brought along with them an ancient but effective command and control system – Music.
They would use bugles, drums, cymbals and many other different types of noise-making items to relay to the masses of troops when, where and how to move or change deployment formations.
To the U.N. forces at first, this was highly unsettling to hear, especially at night, and caused several morale issues. As the war dragged on it became a commonplace thing and was ignored.