Whistles, Flags (yellow), Sandbags(for fumbles)
Any standard whistle used by referees in any other sport will work.
In American football referees use flags to indicate various penalties.
they yelled really loud like. no joke. we still do, but we use whistles to get peoples attention
Dog whistles inflict pain upon the dog with their high frequency noise. The use of dog whistles in dog training is cruel and archaic.
high pitch whistles
Fox 40
The standard is English, but the referees will be able to speak a number of languages to better communicate with the players.
NO
no
No, dolphins use a series of clicks and whistles to communicate
Trainers use dog whistles to train dogs or to get the attention of dogs. A dog whistle frequency is not audible to humans but can be heard by dogs even in noisy places.