Sign into your Trillian account and double click the contact you wish to start a voice chat with. This will open up a new window, with a main texting box where you can type written messages.
Click the blue phone icon at the bottom of the chat window to open up the voice chat. This will send an invitation to that contact to start a voice chat.
Begin your voice conversation once the contact has accepted your request. You will be able to see a volume meter in the window to indicate that your microphone is working.
End the voice call when you are finished by pressing the phone button with the red arrow underneath.
Download and install an antivirus scanner, if you don't already have one on your computer. The best antivirus products will include a scanner, a shield (the part of your antivirus software that is always "on" and monitoring your system for threats) and an internet security package. The scanner runs on command while the shield runs continuously. The internet security package offers protection for internet-related communications and activities, including file transfers and links to potentially malicious websites.
Download and install the latest version of Trillian. As of this writing (January 2010), the latest version is Trillian Astra version 4.0.0.119.
Configure Trillian with your antivirus scanner. You will need to locate the "Preferences" window for Trillian, which will depend on your version and the particular "skin" you are using. Once you have located the Preferences section, find the area heading "File Transfers." Under "Use a Virus Scanner," click the check box next to "Virus Scanner" to select it. Click "Browse," navigate to the location of your antivirus scanner's program file (executable, or .exe file), select the file and click "Open" to set the option.
Keep your software current. Check for antivirus software updates, including any software patches and pattern files, on a regular basis. Keep your copy of Trillian current with the latest patches and updates.