Although CTR-Remote doesn't directly support remote audio to and from the radio, there are available that do.

Using a SkypeIn account is one alternative. The basic Skype program is free. Many hams are using already using it to provide remote audio to their remote radios. Bill Kearns, WB6JAR, has written a great article in the October 2009 issue of CQ Magazine on controlling your radio remotely using CTR-PC and Skype.

MagicJack is another option, however it currently doesn't support the secure dial-in option that SkypeIn does. Check their website for more information.