A sound source apparatus for receiving an audio signal and displaying the audio signal is provided. The sound source apparatus includes at least two sound source output devices, at least two distance sensors, and a processor. Each distance sensor is installed respectively corresponding to each sound source output device, and is configured to respectively detect at least one target to generate sensing signals. The processor receives the audio signal, and when the processor determines that the at least one target meets a sensing range through respectively receiving the sensing signals generated by each distance sensor, the processor calculates output volume of each sound source output device respectively according to a relative distance between each distance sensor and the at least one target.