Revoicer is a good option for realistic voiceovers. It's got more than 80 AI voices in several languages, and you can control speech rate, voice emotion and emphasis on particular words. It's integrated with video editing software, and it's got a range of pricing plans, including a discounted "Standard" plan that's good for educational content creators.
Another powerful option is LOVO, which offers 500+ voices in 100 languages. Among its higher-end features are voice cloning, auto subtitles, AI script generation and built-in audio and video editing. LOVO also has collaboration tools and cloud storage, so it's good for educational content creators with multiple projects.
If you want a broader range of voices, check out PlayHT. It's got more than 600 ultra-realistic AI voices, and it works in multiple languages and accents. PlayHT has several apps including e-learning, audio publishing and conversational AI, and it offers resources and tutorials to help you along the way. It's got a free version, too, so it's accessible to educational content creators on a budget.