Text-to-speech (TTS) and human voice-over are integral to many educational institutions and all interactive voice response (IVR) (
http://www.plumvoice.com/products/ivr-systems) systems.
TTS and voice-over enable educational institutions to design courses and disseminate them on a large scale. They enable organizations to design call flows for IVR systems and deliver messages to a virtually unlimited number of callers 24 hours a day, every day.
But which is better? It depends on the situation and your needs.
TTS:
TTS is faster