I have a Air Evac about 1 air mile from me, and our hospital is about 1.5 miles too. Their base radio (simplex VHF) is about 15 miles West of me. I hear lots of their traffic. The dispatch center (Texas?) uses the base radio via ROIP, and I think the office at the pad can too. I'm not sure if the office has a radio at all, don't see any antenna on it...just a small place.
I hear the dispatches, the chopper take off,etc. I am close enough that many times when the leave the hospital, they fly right over my place. I hear them on Air band too, as we have 2 county airports in close proximity. I have never heard them on HEAR VHF (Squad freq) talking in to the hospital, rather I hear them talk over their own VHF base, and then the dispatch center is patching them to the hospital via phone on the console. Kind of the long way around, but I guess it works for them. Must be some reason they don't want to use 155.340...and it could be the altitude, even with a PL they could hit several hospitals who might be already on theirs listening to a local to them incoming squad.
At any rate, they either have a licensed application in, or will reuse a freq and are waiting for approval in the location. I think the one they have here is used in Texas and Georgia too. They are cool to listen too. I stood 50 feet from one taking off a couple weeks ago at the hospital pad. I would say they are in and out of their base and the hospital 2-3 times a day minimum.
