What would we see if we had glasses that converted sound waves into light waves, assuming our brain became accustomed to them? (Continued)
• As we age, we lose the high end of our hearing range. This would translate to a reduced sensitivity to the blue end of the visible spectrum. The world would seem more yellow - the equivalent of suffering from nuclear cataracts, a subject documented by the artist Claude Monet. Doppler shift in colours could be used to determine relative motion, or at least the component of speed towards or away from you. Run down the street and the scene ahead would be blue-shifted while that behind would be red-shifted.
Mike Follows, Willenhall, West Midlands, UK
To continue reading this article, subscribe to receive access to all of newscientist.com, including 20 years of archive content.