If you work ALOT and for many, many years, you are going to have some hearing loss at some point. When it happens and how bad it gets would depend on how often you are blowing your whistle, which depends somewhat on the position you work.
The type you will have is called Tinnitus and gets worse with age. My father has it from hunting a lot when he was young until he was in his 50's. It is not very treatable and here is a link for you to learn more.
http://www.entnet.org/healthinfo/hearing/tinnitus.cfm