A headphone includes a pair of right and left headphone units, a resilient band formed substantially into a U shape to be mounted on a human head, and a pair of arm members. Each of the arm members is rotatably coupled via a pivot joint to an end part of the band and supporting one the headphone units. Each of the pivot joints includes a detent hinge for locking into a plurality of rotational positions an arm member relatively to the corresponding end part of the band.