I don't see much of anything in my area on the map except for a couple of WX stations and they appear to be using an Internet connection.
If by "map", you mean apris.fi, stop looking at it.
You won't learn anything about the local APRS over RF landscape by looking at a map that draws data from the APRS-IS servers.
Set your radio up to operate in APRS on 144.390 MHz at 1200 baud. You can monitor for a while to see who you can hear with your radio. You should be able to tell who is nearby by watching the display or checking the received stations list. If you want to transmit and you are operating as a base station, set the beacon rate to no less than 10 minutes. While the aprs.fi map does show several fixed weather station that are connected only by the Internet, a quick look shows several more stations operating over RF.
Voice Alert over APRS uses a 100 Hz PL tone. In my opinion, it should only be used by mobiles so that base stations or other mobiles will know that someone else is in range.