Siri Voice Feedback Not Functioning on iPhone 6 (iOS 9) I have an iPhone 6 running iOS 9 – Siri has become speechless all of a sudden. It appears to have went dumb; there is no voice feedback whatsoever.

Siri answers all of my questions correctly with an on-screen response, but there is no voice feedback at all. Can this be sorted without a restore?

PS: I have already performed a Soft Reset.
Voice feedback can be enabled/disabled in Settings -> General -> Siri.