I was recently asked if Alexa can ever speak without prompting, so I thought it'd be helpful to ask here to make sure I'm right; as far as I know, Alexa will never, ever speak without the wake word, and the only unprompted sound it will make is the alarm sound.
This TechCrunch article seems to agree that there isn't any way to make Alexa speak unprompted, but it doesn't mention Alexa skills at all; is there perhaps some API available to them which isn't yet used?
Many people seem to be interested in this so that they can get Alexa to say certain phrases, such as perhaps an alert if the doorbell is ringing, or some way of indicating an event has happened.
Can Alexa speak without first being prompted by either the wake word, tap-to-talk or push-to-talk (depending on the device)? I'm excluding alarms for the purpose of this question, but solutions using custom skills are fine.