Call screening system
Modern android devices have a built-in scam call screening system that automatically determines if a call may be a scam call, and then shows you a "screen call" option. When you screen a call it announces to the caller "Hi, the person you've reached is using a screening service from Google, and will get a recording and transcript of this call. Go ahead and say why you're calling.". The google screen system will translate the speech from the caller into text and display it in a transcript on your screen, as well as allow you to choose from a list of pre-made responses such as "Tell me more" "Is it urgent?" "I can't hear you." etc... If you click to report it as a scam call, it not only blocks the number on your device, but it then also shares that information to other devices so that it can display a "This call may be a scam" message on the incoming call notification.
While a full-scale implementation like that which google has may be out of the question due to complexity (the machine learning suggestions for example), it is likely quite possible to use existing TTS and speech recognition libraries to create a simple open source version of this system that achieves the same functionality.
- Grab from some form of database what calls may be a scam call if they are not in the contacts list or the number has not been picked up before and then display "This call may be a scam". This can also be done with some form of detection like google uses perhaps, such as determining if the caller is using a private or virtual number through using calling information.
- If the user has not added the number to their contacts or ever been in a call with the caller before, the call notification can show a "Screen call" button in between answer and hangup.
- Screen call option will open a separate dialer call UI that not only picks up the incoming call and announces to the caller that the phone is using a scam call screening service using TTS, but then possibly logs the reply from the caller using speech recognition. (and optionally stores said log even after the call alongside perhaps a audio recording from the call)
- Screen call displays an option to unmute and start talking to the person on the other end (while optionally continuing to log the conversation with speech recognition), or report the call as a scam (to whatever database) and/or simply block the number.
- The call screening UI could have templated responses or even a text input box to allow the user to ask questions to the caller as an alternative to how google does it with machine learning templated responses.