A suction regulator arranged to be coupled to a source of partial vacuum and a patient circuit and which is operative in four modes is disclosed. The inorganic material has a formula, AMy, wherein A is comprised of Si or Sn; M is comprised of Al, Ag, Au, Zn, Ti, Ni, Cu, Co, Ta, Fe, W, Cr, V, Ga, Pb, Mo, In or Te; and y is in the range of 0. This invention allows for many different design options, that will give the manufacturer more opportunities for entertaining a child. However, a drain-source on-state resistance is used to replace the consumption of the forward bias when the PMD conducts the electricity on one-way. Various elements are isolated from the microphones to reduce noise and vibration, and an answer bar can be mounted on the integrated unit to provide an easy known answer capability where an automatic answering mode is not desired.