Is there a way to train Alexa to use preferred volume levels, such that Alexa
- plays music at volume X
- replies at volume Y
- sets volume to 0 every night at 9 PM, and back to last set volume at 6 AM
At the moment, it is impossible to set a schedule for Alexa's volume, according to this reddit thread. Instead, you must manually tell Alexa to "set volume to 0" at night, then set volume to [your preferred value]" in the morning.
I believe you can set the alarm/notification volume separately to the master volume in the app (certainly as of December 2016), but I'm unaware of a setting to change music volume separately to voice volume for Alexa's replies.
As always, it may be worth sending feedback requesting this feature if there isn't a solution available; Amazon's team does seem to listen to and prioritise requested features.