Hi Carl – I reviewed and extensive list of TTS options and voices and settled on TextAloud and the Ivona Joey voice. I have some courses up at my testing HTML host if you want to hear what Joey sounds like. There is also Amazon Polly, which has a different pricing structure but could be included if your organization is using any other Amazon Web Service.
During research, I also found a YouTube video with a sample voice that I am going to lobby to add if we choose to add a female voice to the repertoire. There is also on article on the Top 10 TTS options through eLearning Industry.
Some software includes one or more voices, so that may be a route to look into. One reason we picked TextAloud is because it’s a locally run software and voice with a one-time cost for both.