System for localizing sound source and the method therefor

A portable device for localizing a sound source in condition monitoring of the sound source, including:

• a microphone;
• a motion tracking unit, being adapted for tracking a movement of the portable device;
• a processing unit, being adapted for receiving a microphone signal and a motion tracking unit signal and obtaining information on a direction from which sound from the sound source arrives using the received microphone signal and the received motion tracking unit signal obtained during movement of the portable device;
• and
• wherein:
• the portable device is adapted for free movement;
• the processing unit is adapted for evaluating a first Doppler Effect frequency shift of a first microphone signal with respect to a first directional movement of the portable device from an initial position;
• the processing unit is adapted for providing the information on the direction depending on the first Doppler Effect frequency shift of the first microphone signal and a motion tracking unit signal for the first directional movement of the portable device;
• the processing unit is further adapted for evaluating a second Doppler Effect frequency shift of a second microphone signal with respect to a second directional movement of the portable device from the initial position;
• and
• the processing unit is adapted for providing the information on the direction depending on the first Doppler Effect frequency shift and the second Doppler Effect frequency shift of the first and second microphone signals and motion tracking unit signals for the first and second directional movements of the portable device.