An integrated circuit, configured to process microphone signals, where the integrated circuit comprises: a preamplifier (306) with an amplifier section (301) which has a first input (φ) and a second input (φ*) and an output (φ), and with a feedback filter network (Z1; Z1, Z1*, Z2) coupled between the output (φ; φ, φ*) and the second input (φ′); where the first input (φ) to the amplifier section (301) has an input impedance which by means of the input impedance of the amplifier section is substantially isolated from the feedback network with respect to input impedance; and where the preamplifier has a frequency-gain transfer function which suppress low frequencies; and an analogue-to-digital converter coupled to receive an anti-aliasing filtered input signal and providing a digital output signal (Do).