Portable device and method for providing voice recognition service

A portable device comprising:

• a mechanical vibration sensor configured to sense vibrations having a magnitude equal to or larger than a threshold and generate an electrical signal;
• a motion sensor configured to sense a motion of the portable device;
• an audio sensor configured to receive a voice command;
• a sensor hub configured to control a plurality of sensors including the motion sensor and the audio sensor;
• and
• a main processor configured to execute an application and control the portable device,
• wherein when the portable device is placed in standby mode, the sensor hub switches from inactive state to active state and activates the motion sensor when receiving the electrical signal from the mechanical vibration sensor, and if a gesture pattern sensed by the activated motion sensor corresponds to a voice recognition service triggering gesture, the sensor hub transmits a signal to the main processor, the signal activating the main processor and switching the portable device from the standby mode to voice recognition service mode.