In this paper, the design and measurement of a 1-V current-companding integrator and its application in a controllable second-order lowpass filter for hearing instruments is presented. The filter operates at voltages down to 1 V, consumes only 6 ??A and has a dynamic range of 57 dB for a total harmonic distortion below 2 %. Its cutoff frequency is linearly adjustable in octaves from 1.6 to 8 kHz.