AT+ECHO AT command is used to suppress echo for handset and handsfree audio channels.
Simcom Module Tutorial
//Echo cancellation command support
//set echo suppression for main audio channel
|Keywords||AT+ECHO syntax, examples, parameters, error, input, response.|
With Online AT Command Tester tool, you can test this feature.
With Online AT Command Tester tool, you can also get device diagnostic information easily,