A method of detecting defects in a high impedance network of a MEMS microphone sensor interface circuit which comprises: a) a charge pump; b) a low-voltage high impedance network coupled to a direct current potential and to a sense node, the low-voltage high impedance network including a set of anti-parallel diodes (135, 140) and a low-voltage reset switch connected across the antiparallel diodes (135, 140) through a diode, the direct current potential being coupled to one connection node of the anti-parallel diodes (135, 140) and the sense node coupled to another connection node of the antiparallel diodes (135, 140); c) a high-voltage high impedance network coupled to the charge pump and to a bias node, the high-voltage high impedance network including a set of anti-parallel diodes (155, 160) and a high-voltage reset switch connected across the antiparallel diodes (155, 160) through a diode, the charge pump being coupled to one connection node of the anti-parallel diodes (155, 160) and the bias node coupled to another connection node of the antiparallel diodes (155, 160); d) a sense capacitor coupled between the sense node and the bias node; e) a high impedance amplifier coupled to the sense node; and f) an output capacitor coupled between the bias node and ground; said method comprising the steps of: g1) closing the high-voltage reset switch during a start-up phase of the MEMS microphone sensor interface circuit; g2) closing the low-voltage reset switch during the start-up phase of the MEMS microphone sensor interface circuit; g3) simultaneously opening the high-voltage reset switch and the low-voltage reset switch at the end of the start-up phase; and g4) detecting a defect in the high-voltage high impedance network or the low-voltage high impedance network immediately after opening the high-voltage reset switch and the low-voltage reset switch; g51) wherein the defect is a leakage current between the bias node of the MEMS microphone sensor interface circuit and ground, or g52) wherein the defect is a leakage current between the bias node of the MEMS microphone sensor interface circuit and the sense node of the MEMs microphone sensor interface circuit; wherein g6) the detecting of a defect in step g4) comprises the detection of deviations in the sense node voltage after start-up, with the magnitude and rate of the sense node voltage deviation corresponding to the amount of leakage. a) a charge pump; b) a low-voltage high impedance network coupled to a direct current potential and to a sense node, the low-voltage high impedance network including a set of anti-parallel diodes (135, 140) and a low-voltage reset switch connected across the antiparallel diodes (135, 140) through a diode, the direct current potential being coupled to one connection node of the anti-parallel diodes (135, 140) and the sense node coupled to another connection node of the antiparallel diodes (135, 140); c) a high-voltage high impedance network coupled to the charge pump and to a bias node, the high-voltage high impedance network including a set of anti-parallel diodes (155, 160) and a high-voltage reset switch connected across the antiparallel diodes (155, 160) through a diode, the charge pump being coupled to one connection node of the anti-parallel diodes (155, 160) and the bias node coupled to another connection node of the antiparallel diodes (155, 160); d) a sense capacitor coupled between the sense node and the bias node; e) a high impedance amplifier coupled to the sense node; and f) an output capacitor coupled between the bias node and ground; g1) closing the high-voltage reset switch during a start-up phase of the MEMS microphone sensor interface circuit; g2) closing the low-voltage reset switch during the start-up phase of the MEMS microphone sensor interface circuit; g3) simultaneously opening the high-voltage reset switch and the low-voltage reset switch at the end of the start-up phase; and g4) detecting a defect in the high-voltage high impedance network or the low-voltage high impedance network immediately after opening the high-voltage reset switch and the low-voltage reset switch; g51) wherein the defect is a leakage current between the bias node of the MEMS microphone sensor interface circuit and ground, or g52) wherein the defect is a leakage current between the bias node of the MEMS microphone sensor interface circuit and the sense node of the MEMs microphone sensor interface circuit; wherein g6) the detecting of a defect in step g4) comprises the detection of deviations in the sense node voltage after start-up, with the magnitude and rate of the sense node voltage deviation corresponding to the amount of leakage.