The following applet is triggered whenever the transmit rate on the given interface falls below the configured threshold.

event manager applet speaker_monitor_Gi7/0/9 authorization bypass
event interface name GigabitEthernet7/0/9 parameter transmit_rate_bps entry-op le entry-val 1500000 entry-type value poll-interval 120
action 1.01 syslog msg "------ EEM GENERATED MESSAGE ---------"
action 1.02 syslog msg "----- SPEAKER RECEIVE RATE UNDER 1.5Mbps DETECTED ----"
action 1.03 cli command "enable"
action 1.05 cli command "configure terminal"
action 1.07 cli command "interface GigabitEthernet7/0/9"
action 1.08 cli command "shutdown"
action 1.09 wait 5
action 1.10 cli command "no shutdown"
action 2 mail server "$_email_server" to "$_email_to" from "$_email_from" subject "Dante Speaker was rebooted" body "Dante Speaker on port GigabitEthernet7/0/9 was rebooted due to not receiving multicast audio stream."

courtesy of Chris Partsenidis