A method, which is performed in an electronic device, for activating a target application is disclosed. The method may include receiving an input sound stream including an activation keyword for activating the target application and a speech command indicative of a function of the target application. The method may also detect the activation keyword from the input sound stream. If the activation keyword is detected, a portion of the input sound stream including at least a portion of the speech command may be buffered in a buffer memory. In addition, in response to detecting the activation keyword, the target application may be activated to perform the function of the target application.