I had a look for the voice, but I couldn't find it. Its intonation reminds me of one I heard a few years ago that is no longer available, but I'm not sure. Some similar voices you might want to try are James from Neospeech and Will from Acapella. You might also want to try posting to r/texttospeech or the audiogames.net forum. Let me know if you ever find out what the voice is.

I hear that voice a lot but I don’t know if I’ve ever heard it on a screen reader. I highly suggest playing with the voices on your device, especially with tone and speed. That voice is using an American accent so check out those first (and if you are using iOS try the enhanced version of the male American voice). I think you can adjust voice pitch too and setting that lower might be helpful.