A circuit for sound activity detection includes a transducer (106) adapted to generate an electrical signal based on detected sound; a variable gain amplifier adapted to amplify the electrical signal to generate an amplified electrical signal; a comparator adapted to compare the amplified electrical signal with at least one first threshold level to generate a comparison signal indicating comparator events; and a control circuit adapted to generate, based on the comparison signal, a gain control signal for controlling the gain of the variable gain amplifier, and a sound activity alert signal indicating the detection of sound activity.