Little Green Button allows you to choose whether you would like an audible alert to accompany alerts. This setting is configured by each user, click here for guidance.
If you need to change this setting for multiple users you can do this by locating and changing the setting within the shared.xml file which is accessed by each user.
To locate this file, hold down the Shift key and right click on the Little Green Button, go to Find In Explorer and select User Data. If the file is absent, this indicates that default settings are currently being used, making any change within Settings will create this file.
In this file you will see the following line:
To prevent the audible alert amend this line to: