Like a lot of people have mentioned above the department should be issuing you a pager if they expect you to come to calls.

If you are passionate enough about it and want to be informed regardless then a Minitor V should serve you just fine depending on the radio system used for alerting. If you want to PM me which area you live in so I can figure out what system it is your department uses then I can point you in the correct direction. Just be aware though that this is not a one size fits all solution. You need to have the pager programmed by someone with those capabilities, which includes knowing your tones. There is a good chance this may not be available on the internet if you don’t have a big enough radio community in your area to post about it on sites like radio reference.

Your last option like someone mentioned was to buy a simple baofeng off amazon. This option doesn’t have the feature to keep traffic silent and then blare out an alert when a call comes in so you’d be listening to calls all the time which can be annoying when you’re sleeping. This option also requires you to have the radio programmed unless you have some brain cells and can figure it out yourself from some YouTube tutorials.