sensor which can be piggy backed as shown or conjoined side by side could be used in all of the embodiments shown previously the present subject matter provides ways to arrange and mount a sensor within the housing of an ite housing instrument so as to improve the speech intelligibility of the sensor 39 s output signal unique aspects of the present subject matter include but are not limited to 1 a single passive pressure differential electret microphone can be used for enhanced speech intelligibility 2 the passive pressure differential microphone can have either a 1 st or 2 nd order freefield response 3 the mounting suspension stiffness is engineered to resonate with the mass of the differential microphone so as to amplify and enhance the sensor 39 s bone conduction response in the sii weighted frequency bands engineering includes the choice of elastomer and its geometrical dimensions particularly its thickness 4 the tension and effective mass of the elastomeric window barrier integrated into the wall of the plastic housing is engineered to resonate with the stiffness of the air cavity within the plastic housing so as to amplify and enhance the sensor 39 s response in the sii weighted frequency bands engineering includes the choice of elastomer and its geometrical dimensions particularly its thickness and 5 a combination module containing both.