Composite Source Signals
As I was working on simulations for my thesis, I needed some useful signals to apply my algorithms to. The ITU G.168 echo canceller standard describes Composite Source Signals (CSS). These were made to have similar properties to real speech signals. They are intended to be used for testing echo cancellation devices. Although I never ended up using them much, they can be useful for comparing algorithms and simulating double talk. They are broken into voiced and unvoiced portions. There are two voiced versions at different frequencies. They can be used together for double talk. I don't remember how the scripts work. You may need to take a look at G.168. Also note that there is already a resample function in matlab.