With iOS 10 and above Apple made it possible for iPhone devices to use Siri for announcing caller’s name when you receive a call. This option is disabled by default, but you can enable it and enjoy this feature.
With this feature enabled, whenever someone calls you Siri will tell you the name of the caller (if a known/saved person is calling you) and if the caller is unknown or the number is not saved, it will announce “Unknown Caller” as it cannot find the name of the caller in your phone book.
But how you can enable it?
Step 1. Go to Settings app > Scroll down and choose Phone.
Step 2. Tap on Announce Calls > Choose one option you prefer.
Always: It will announce caller’s name in any case.
Headphone & Car: It will announce caller’s name when you are using headphones or in a car.
Headphones Only: It will announce calls when you have headphones plugged in.
If you want to turn Announce Caller off, you can choose Never option. Then it will prevent your iPhone from speaking caller’s name.