Ventilation and noise reduction housing and assembly, ventilation and moisture retention apparatus, breathing mask assembly, and breathing support device

A ventilation and noise reduction housing, comprising a respiratory passage segment, a first end of the respiratory passage segment being a ventilation and noise reduction housing connection end, the other a second end of the respiratory passage segment being a respiratory tube communication end, wherein a wall of the respiratory passage segment comprises a ventilation-noise reduction unit mounting wall segment, the ventilation-noise reduction unit mounting wall segment is provided with exhaust vents and a supporting protrusion structure protruding from an outer surface of the ventilation-noise reduction unit mounting wall segment, and the supporting protrusion structure is configured to support a ventilation and noise reduction core of a ventilation and noise reduction unit disposed on the ventilation-noise reduction unit mounting wall segment, so that a ventilation gap is at least partially maintained between the ventilation and noise reduction core and the outer surface of the ventilation-noise reduction unit mounting wall segment.