Digital voice on HF SSB has been the unpickable fruit for a long time. A team of hams has found a way to get around all the patent / copyright issues and has published FreeDV. Software any ham can use to experience digital voice on the HF bands. All you need is a computer and a sound card interface.
Here’s the link… http://freedv.org/
If you are using FreeDV or something similar and would like to suthor an article on your experiences the please e-mail SERC@N4ser.org