Nick, I wish some of that research had continued with sonic devices; I own and still use a Mowat sensor; it's saved my life many times, since I'm deaf on one side and have no way of using sound for orientation. There are new devices out there, but I gather their range isn't like the older devices. Getting back on track with the optacon, let's hope that any new optacons that are developed will have the same capability as the one we know and love. Mary to view the list archives, go to: www.freelists.org/archives/optacon-l To unsubscribe at any time, just send a message to: optacon-l-request@xxxxxxxxxxxxx with the word "unsubscribe" (without the quotes) in the message subject. Tell your friends about the list. They can subscribe by sending a message to: optacon-l-request@xxxxxxxxxxxxx with the word "subscribe" (without the quotes) in the message subject.