To block one or more users within the chat room, navigate to your Profile Settings page which can be found here:
Under the Block Chat Users section, enter one or more usernames of users that you would like to block. Separate each username with a comma as shown below.
Then click Save Profile at the bottom of the page. If you have any chat windows or the dashboard opened, be sure to reload the page for the new settings to take effect.
By blocking a user, you will no longer be able to see their messages within the chat and notification sounds are disabled for any incoming chat messages from that user(s).
To unblock a user, simply remove their username from your block list.