A hearing aid device includes a signal transforming unit for converting an analog sound signal received by a signal receiving unit to a digital signal; a memory unit for temporarily storing the digital signal; a sound processing module for reprocessing the sound signal stored in the memory unit via a microprocessing unit according to parameters set by a user; a sound control module for receiving the sound signal processed by the sound processing module and adjusting an output volume via the microprocessing unit; and a signal output unit for receiving and outputting the sound signal adjusted by the sound control module. By such arrangement, a speed, tone and/or volume of an output sound can be controlled using the hearing aid device to thereby help the user to receive and recognize the sound signal.