It could be that Orca is not enabled in the startup applications on the live image (32-bit). I know it is when the 64-bit image is installed, because Alt + Super + S starts the screen reading. One quick check to try is to open a terminal (do this with ctrl-alt-t). Then at the prompt type orca and then a carriage return, and hopefully it says, "Screen reader on". If this gets it working, it is likely that Orca is not enabled in the startup applications for that 32-bit live image. I hope to test either with the 32-bit 15.10 image or the 16.04 alpha/beta image(s), within a couple of weeks.
It could be that Orca is not enabled in the startup applications on the live image (32-bit). I know it is when the 64-bit image is installed, because Alt + Super + S starts the screen reading. One quick check to try is to open a terminal (do this with ctrl-alt-t). Then at the prompt type orca and then a carriage return, and hopefully it says, "Screen reader on". If this gets it working, it is likely that Orca is not enabled in the startup applications for that 32-bit live image. I hope to test either with the 32-bit 15.10 image or the 16.04 alpha/beta image(s), within a couple of weeks.