The present disclosure provides an open earphone comprising: a sound producer including a transducer and a housing accommodating the transducer; and an ear hook, the ear hook including a first portion and a second portion; wherein the ear hook and the sound producer form a first projection on a first plane, the first projection including an outer contour, a first end contour, an inner contour and a second end contour, and the outer contour, the first end contour, the second end contour and a tangent segment connecting the first end contour and the second end contour jointly define a first closed curve.