The reader is not human. The voice is AT&T Natural Voice NeoSpeech Paul 16 using TextAloud at settings -3 & -3, 24 kbps to minimize file size, quality is the same. Total time is about 48 hours. I couldn't find any audios of this book so made my own. Not that great, many errors, could be better, but still better than any other audio of this book which I couldn't find. Many of the Kzin names are spelled out rather than spoken because the TTS program didn't recognize them as speech.
I'll be finishing the Known Space Tales & short stories, not found in audio elsewhere, in the near future.