Indirectly, they can be used. If you enable audio prompts, they work with a CIQ device app. So if you set a Heart Rate alert, you get them. If you have Lap Alert, you get them when you do an addLap().
Thanks for the workaround. So it's very limited. Hopefully if it's more common, there will be a direct support of voice prompts. I'm thinking about prompts for interval training etc...
That's true. You can only call addLap in a device app. Not in a data field
In a DF, laps come from a native app. So in the sim on something the a 645m, after you've started, you can click on the lap button (lower right) to mark a lap. Or from the Data Fields menu, go to "Timer" and then "lap activity".