An earphone with adjustable volume of a front chamber between a speaker
and a housing is provided, which includes a speaker unit, a housing and a
movable element. The speaker unit is disposed within the housing, and the
housing includes an earplug formation formed in front of the speaker
unit. A chamber within the earplug formation has a volume, and the
movable element is disposed on the housing and moves correspondingly with
the chamber, so as to adjust the volume of the chamber. Therefore, the
frequency response of the sound sent by the speaker unit varies depending
upon the variation of the volume of the chamber.