Audio Visual

This is for a device to help blind people become more self dependant.A blind person carries this device on them much in the same way as a hearing aid, but it has a bluetooth receiver. This receiver picks up audio recordings that are sent to the device when it enters a designated area. this streams audio to the user, giving them an audio map of the area. For example: when entering a tube station, the hearing aid notifies the user with an audible beep/blip to tell the user there is information about the area they are in. they access it by choice, by tapping the device. The user then hears a menu of sorts, asking for a choice of what they want to know. they select what they want to know, such as a cash machine or help desk, or information point. they then hear the message and follow the instructions. i understand this is an idea with a lot of complications, such as descriptions of the area, and how it would help, but i think ideas like these need alot of input from alot of people...any one else want to put some pennies of thoughts in......