Do Neapolitan Mastiffs bark much?

No, most Neapolitan Mastiffs do not bark much. They tend to be more on the quiet side, primarily barking when they sense a threat or feel the need to protect their family. Their natural guarding instincts make them alert and watchful, so when a well-socialized Neapolitan Mastiff does alarm bark, it’s usually for a good reason. 

That said, like any dog, they can develop barking habits if they’re bored, anxious, or lack access to consistent companionship, exercise, enrichment, and restorative sleep.