I think we tend to neglect senses other than sight when talking about AR. In my opinion, the Apple Watch (and other smartwatches) are AR devices; tapping my wri

I think we tend to neglect senses other than sight when talking about AR. In my opinion, the Apple Watch (and other smartwatches) are AR devices; tapping my wrist to tell me to turn left is an example of AR behavior. Touch is much easier than sight, smell, and taste. Sound is an interesting possibility. And yeah -- headphones are an AR device. If your headphones are capable of doing outside noise cancellation, it's not that much further to a set of headphones that can pick out crucial sound and augment appropriately. And of course the classic implementation is museum headphone tours...