Ham radio communication often involves leaving a radio on to a frequency or a local repeater, where you listen for a buddy to call you. Well, that can be annoying if 10 different users and lots of kerchunks interrupt the general silence on the frequencies from time to time.
Hearham.live is a new experiment building a listener to alert via SMS text message whenever a call sign is used on the radio.
Previously a SDR with voice recognition was required to set up, and no one successfully set this up yet - in my own experiments while building it I found it to really not work so well with any static on the radio, and problems with voice recognition.
DMR however has a digital listing of call signs as they call in to the system through one of hundreds of repeaters around the world. This requires a DMR capable radio (such as the AnyTone D868UV or Radioddity GD77) programmed to listen to a local DMR hotspot/repeater.