Method and apparatus for processing audio signal

A method and apparatus for processing an audio signal are provided. The method of processing an audio signal comprises a step of outputting a first audio signal; a step of receiving the first audio signal and a second audio signal outputted from another audio signal processing apparatus; a step of detecting a first synchronization signal and a second synchronization signal from the first audio signal and the second audio signal, respectively; a step of detecting a first synchronization error by calculating an input time difference between the first synchronization signal and the second synchronization signal; and a step of performing synchronization based on the first synchronization error. So, optimal sound quality can be provided.