Mike,
Is the app / driver call for native TTS the same as SmartThings; i.e.,
def sound = textToSpeech(text)
def trackUrl = sound.uri
def duration = sound.duration
BTW. I am single, so no wife. However, my Amazon Echo has requested that we go into couples counseling. I am suspicious she is having an affair with the thermostat! Way too cozy around here!