The Polly speech engine launched with 47 male and female voice and support for 24 languages. Since then, Amazon added support for Korean, another 5 languages, and made Polly available in all regions in the AWS partition.
The technology’s capabilities have also evolved, with added support for things like whispering, speech marks, a timbre effect, and dynamic range compression. These sorts of voice technology advancements are also things that make Alexa sound more natural, too. Similar to Polly, Alexa learned how to whisper and change the pitch of her voice earlier this year.
Once set up, the plugin makes calls to Amazon Polly whenever a blog post is saved or updated.
I installed the plugin this afternoon, and I've been testing it. It hasn't actually worked for me so far, and it's not clear why. This is a 1.0 release, so it might just be buggy, but it might be that the plugin requires a paid Amazon Polly account (this point wasn't clearly stated anywhere).
I would keep trying, but I'm having trouble even getting the Amazon Polly settings menu to respond promptly. I think I will wait until after the first update, and try again.
Amazon Polly is by no means the first automated TTS platform, or even the first to offer a WP plugin; I recall briefly testing one back in 2010. I stopped using that earlier platform because the voice quality was mechanical at best, but the tech has advanced considerably in the past seven years.
The Amazon Polly voices are based on the same tech used in Alexa, and as you know that sounds quite pleasant.