Totally understand - at the moment I was just asking for registration so I can stay in touch with people who might be interested as more features get added or when the larger app is released.

In the meantime, I've enabled e-mail registration without verification, so feel free to signup with a throwaway :)

Okay, I did. Now I have to say that I do not find this helpful. The audio is very synthetic and has audio distortions. 三 had a weird glitch in it. Have you tried using one of Bidu's models?

Also, in counter part to Duolinguo, I suggest at checking out Hello Chinese, and using that as the metric to beat (it is popular among Mandarin learners).

Thanks for taking the time out to provide your feedback, it's always very helpful.

You're right, there are a few artifacts in the audio. Most of these are due to generating speech at a slower cadence than "natural".

Native/enunciated recorded speech would probably be better for this specific purpose, but not necessarily practical for the larger app.