An interesting solution to unwanted Robocalls and other telephone irritations has emerged in the form of the Banana Phone Project. Developed by Alex Ruiz using the ever versatile Raspberry Pi computer, he describes this as the evolution of caller id.
The device itself is not actually a phone that looks like a banana (I used to have one of those) but is instead a means of screening your calls to ensure that only worthy humans get through. It does this by playing an audio file to callers who have not been already been white-listed or approved as a human caller. The audio file is complicated enough to fool a machine, but the four letter code that is played on top of other noise is easy for the human ear/mind to pick up.
Once the code is entered, that human is able to get through as well as call back again and bypass the verification system. Such an approval can be permanent or expire after a set period of time.
Similar to CAPTCHA software this could go a long way towards ending unsolicited phone calls.
Alex was motivated to create this solution in response to the FTC Robocall Challenge. I suspect he was one of many entrants and it will be interesting to see what other solutions emerge.
His video below explains the features of the Banana Phone Project which even at this early stage is quite impressive: