That is true - all voice related interfaces are best exemplified with travel. STT for example is best when you're alone and can't use your hands aka driving. TT

That is true - all voice related interfaces are best exemplified with travel. STT for example is best when you're alone and can't use your hands aka driving. TTS is best for the same set of situations, so listening to articles on the train or getting directions read back. In general, TTS is a better interface than STT, both are (in my very, very humble opinion) bad interfaces.