Abstract: The invention discloses an earphone device comprising a first case, a first speaker unit, a first recording unit, and a second recording unit. The first speaker unit, disposed inside the first case, emits a first testing sound signal according to a test command. The first recording unit, disposed inside the first case, records a first environment sound signal according to a record command or a noise cancelling command. The second recording unit, disposed inside the first case, records a first feedback sound signal, related to the first testing sound signal, according to the test command.