A user interface apparatus using a speaker to control device operations by utilizing a speaker and a method thereof are provided. The user interface apparatus includes a user input pad that forms at least a portion of the exterior of a speaker and is configured to generate an impact sound wave based on an external impact An impact sound wave recognizer is configured to receive feedback of an output signal output via the speaker and separate a reverse current signal due to the impact sound wave included in the feedback signal. In addition, a controller is configured to analyze a waveform of the reverse current signal separated by the impact sound wave recognizer to recognize a user input pattern, and output a control signal that corresponds to the recognized user input pattern. The device operations of various devices may be controlled by tapping or flicking the exterior of a speaker.