No microphone setting?
I just started this course on the web, and had previously set my microphone to "off" for another course. I realised that I wasn't getting any speaking exercises in the Japanese course, so went to my settings to turn the microphone back on. I could only see settings for turning the speaker and sound effects on and off.
Are there voice exercises for the Japanese course? Has the microphone been dropped as a feature? Am I experiencing a bug?
I think there are no such exercises yet. In my experience this has been the norm for courses, even with full audio, that launch during Beta. Russian was like this at the start, but it wasn't long before they actually added voice exercises.
My main complaint here is the lack of communication from DuoLingo. Is this something they plan on adding or not? I have no idea...I'm left totally in the dark, as I am about my more serious complaints like the lack of open-ended typing exercises (something that personally concerns me much more than the lack of microphone exercises, although ideally I'd like both).
It's been a year since you posted this but... Yeah, there aren't any microphone exercises for the Japanese course yet.
The V2 Tree is being worked on though, and we'll see if it adds such exercises.
UPDATE: V2 Tree Beta will be available to new members of Duolingo very soon. Here for more details: https://forum.duolingo.com/comment/30544388