At the command prompt, type change system-parameters features and press Enter.
In the Zip Tone Burst for Callmaster Endpoints field on the Feature-Related System Parameters screen, select single to eliminate the second burst of zip tone or Incoming Call Identification (ICI) tone.
The single field option reduces:
The time for an agent to begin a conversation with the caller.
The possibility of an agent and a caller hearing an open mike background noise between the first tone and second tone.