Abstract: An externally-connected audio apparatus and a method for processing the audio signals are described. This approach is primarily to improve the externally-connected audio quality by applying a memory sharing mechanism into an audio apparatus. Preferably, the audio apparatus has one end connected to a computer system through an interface control unit, and another end outputting or receiving external audio signals through an audio interface unit. A memory control unit is particularly introduced to be an arbiter for the built-in buffer memories—including the memory for storing the data transmitted through the interface control unit, and the memory for buffering the data to be analog-digital conversion. The memory control unit is to control the data buses of buffer memories and determine whether a sharing mode is activated or not. One of the objectives is to increase the capacity for buffering the audio signals so as to enhance the audio quality.