Can audible warnings be heard from the cabin?
On the Airbus even with O2 masks, loudspeakers aural alarms level ( normal or abnormal) can’t  be adjusted by the crew, these are such as ground proximity alarms or stall alarm, or engine fire, degradation in autoland or autopilot disconnect, single amber gong, repetitive red gongs, altitude hold deviation, altitude decrements  at flare etc

As these loudspeakers sound levels are not adjustable, and as the cockpit is not sound proof, these aurals  are heard  in the very front rows.