An own voice suppression apparatus applicable to a hearing aid is disclosed. The own voice suppression apparatus comprises: an air conduction sensor, an own voice indication module and a suppression module. The air conduction sensor is configured to generate an audio signal. The own voice indication module is configured to generate an indication signal according to at least one of user's mouth vibration information and user's voice feature vector comparison result. The suppression module coupled to the air conduction sensor and the own voice indication module is configured to generate an own-voice-suppressed signal according to the indication signal and the audio signal.