a voice radio communication system prioritizes radio voice communications so that higher priority voice transmission is given precedence . the communication system comprises a transmitter that inserts a digital watermark into a voice communication . software in a receiver decodes the digital watermark to determine a priority requested by the sender , and other information about the sender and the message . the software determines the message priority based on multiple factors . voice transmissions are digitally recorded and played in order of priority . options exist for the user to control the playback .