Yes, it appears so. I started recording a call to the L5 from my other phone and then walked into a separate room. The app recorded my voice clearly, but I’m not sure whether the source it was picking up was the ear-speaker or the internals. (Kind of hard to test this by process of elimination when you’re just talking to yourself.) Sounded good enough to be internals, though.
You could contact the developers of the Sound Recorder app to find out for sure. https://wiki.gnome.org/Apps/SoundRecorder