Using ChromeVox (and Chrome) in Ubuntu. If you tab to the add activity/resource link and press enter you get the dialog. Tab to the first option then you can use the up and down arrows to move between the various activities. The problem is that ChromeVox just announces all of them as "radio button" and doesnt tell you what activity/resource is associated with the radio button.

There's some garbled sound as it sounds like its trying to play several sounds at once with each new sound cancelling the previous sound. The last sound is "radio button" so thats all you hear.