US Patent 9319767 Earphone

An earphone includes: a loudspeaker unit; a sound conductive tube which is connected to a front surface having a diaphragm included in the loudspeaker unit, and has a hole through which a sound generated from the loudspeaker unit is emitted; a housing which is connected to a back surface of the loudspeaker unit so that a space is formed between the housing and the back surface of the loudspeaker unit, and has a first air hole connecting the space to external air; a first braking part which closes a sound hole of the loudspeaker unit; and a second braking part which closes the first air hole.