An audio output circuit includes a port attenuation circuit, which is configured to convert an abrupt dc voltage offset transition between a pair of audio signals received in sequence at an input thereof into a more gradual transition. This conversion is achieved by performing, in sequence, a ramp-to-mute operation on a first of the pair of audio signals and a ramp-from-mute operation on a second of the pair of audio signals. The ramp-to-mute operation includes ramping an output of the audio output circuit from a dc voltage offset associated with the first of the pair of audio signals to a reference dc voltage offset. The ramp-from-mute operation includes ramping the output of the audio output circuit from the reference dc voltage offset to a dc voltage offset associated with the second of the pair of audio signals. These ramping operations may be performed using voltage steps having uniform step size.