A microelectromechanical-acoustic-
transducer assembly has: a first die integrating a MEMS sensing structure having a membrane, which has a first surface in fluid communication with a front chamber and a second surface, opposite to the first surface, in fluid communication with a back chamber of the microelectromechanical acoustic 
transducer, is able to undergo deformation as a function of incident acoustic-pressure 
waves, and faces a rigid 
electrode so as to form a variable-
capacitance capacitor; a second die, integrating an electronic reading circuit operatively coupled to the MEMS sensing structure and supplying an electrical output 
signal as a function of the capacitive variation; and a 
package, housing the first die and the second die and having a base substrate with external 
electrical contacts. The first and second dice are stacked in the 
package and directly connected together mechanically and electrically; the 
package delimits at least one of the front and back chambers.