It entirely depends on why they are yelling.
A yeller is someone who yells at someone else.
it means they crazy
Reprogram it.
Yells is not a person Yells is not a place Yells is not a thing Yells is a Verb.
Their workplace.
shut the door in her face
yells and cheers
If a risk/hazard is identified in the workplace and it is not dealt with, or reported to someone who can deal with it, then someone may be injured.
It is when someone ggets clobbered over the head. The other person yells sambong!
Boy Scout yells may include patrol yells and troop yells. These are used to unify the Boy Scout troop. Other yells include those for meals or celebration.
I hate to be blunt, but if you need to ask how? then you shouldn't be supervising anyone. How about taking some form of training course?
It certainly is, you should report it to a manager and if you don't feel comfortable reporting it to them you can research someone higher, they should take it very seriously and most certainly should take action!!