Ed is blind and uses a Plantronics Bluetooth headset with his iPhone. When he gets an incoming call while he's on a call, he can't do anything without cutting off his current call. Leo says that call waiting is an imperfect technology and he doesn't use it. Leo says that if he can tell Siri to put it on hold, and take the other one, that would be great. Ed should talk to an Apple Genius at the Apple Store. They may know something.