IVONA Software IVONA SAPI5 TTS Engine (ivona-software-sp.z-o.o.ivona-software-ivona-sapi-tts-engine.ivona_sapi-dll) is a Windows software application that has been discovered and submitted by users of Software.com. The latest version that our users have reported running on their systems is IVONA Software IVONA SAPI5 TTS Engine 1.6.63.0.