The present disclosure provides an apparatus for audio signal output. The apparatus may include a bone conduction assembly configured to generate a bone conduction acoustic wave. The apparatus may include an air conduction assembly configured to generate an air conduction acoustic wave, the bone conduction acoustic wave and the air conduction acoustic wave may represent a same audio signal. The apparatus may include a phase difference between bone conduction acoustic wave and the air conduction acoustic wave may be smaller than a threshold. The apparatus may include a housing configured to accommodate at least a portion of the bone conduction assembly and the air conduction assembly.