https://cloud.google.com/text-to-speech
MS offers a similar service:
https://azure.microsoft.com/en-us/services/cognitive-service...
Both default to voices seem a little tinny to me, but both are customizable. We use one of these services for a US audience with a European accent as we find that further obfuscates the generated speach.
Elaborate so that we know what you want. Perhaps some products can be tuned to your liking.