An audio amplifier (3) for a mobile telephone (1) is disclosed. The audio amplifier (3) comprises first and second output stages (11, 12), each for coupling to a respective one of first and second loudspeakers (4, 5), and switching circuitry (10) adapted to respond to a switching signal by switching an output signal from a common input stage (7, 8, 9) to the first output stage (11) when the switching signal is in a first state and to the second output stage (12) when the switching signal is in a second state.