Ultrasonic "sight" for the blind

Hi,

Many apologese if I am posting in the wrong forum but .....
Has anyone designed an Ultrasonic device to allow the blind to "see". Like a destroyer pinging a U-boat or a car parking sensor.
Say a varying frequency of the return ping depending on range and feeding audio into the left or right ear depending on relative position. The transceivers mounted on a headband to work in the direction the person is "looking".
I can't believe that there isn't a commercial unit out there but any links and suggestions would be much appreciated.

Thanks

Mike

I played around a little with the concept once, but never got so far as making a full prototype. I was thinking along the lines of an FMCW "chirp", much like bats use.

I do believe they have canes that have these types of sensors in them--do a thorough google search.

Added after 1 minutes:

http://atwiki.assistivetech.net/inde..._who_are_blind