A system is provided for providing location-specific images to a mobile device for display. The method also includes detecting motion of the actuator using a position sensor that exhibits noise in the detected motion, and controlling the position of the actuator using a feedback loop and a feed forward algorithm. In another embodiment, a method may comprise formatting a data storage memory with a first track having a first track pitch, and formatting the data storage memory with a second track having a second track pitch. The housing is shaped, and the opening is located, so that the volume of yielding material comes into contact with an ear or cheek of a user who is using the personal audio device. In addition, the risk of the feed hose kinking is kept small. According to the light-emitting device having such arrangement, the light can be emitted efficiently by synergetic effect of the reflective layer and the recessprojection portion.