Earphone device

An earphone device, comprising:

• a first case;
• a second case;
• a first speaker unit, disposed inside the first case, emitting a first testing sound signal according to a test command;
• a first recording unit, disposed inside the first case, recording a first environment sound signal according to a record command or a noise cancelling command;
• a second recording unit, disposed inside the first case, recording a first feedback sound signal, related to the first testing sound signal, according to the test command;
• a second speaker unit, disposed inside the second case, emitting a second testing sound signal according to the test command;
• a third recording unit, disposed inside the second case, recording a second environment sound signal according to the record command or the noise cancelling command;
• a fourth recording unit, disposed inside the second case, recording a second feedback sound signal, related to the second testing sound signal, according to the test command;
• and
• a processing unit coupled with the first speaker unit, the first recording unit, and the second recording unit, and providing the test command, the record command, and the noise cancelling command,
• wherein the second recording unit further records a third environment sound signal according to the noise cancelling command, the processing unit further provides a first noise cancelling sound signal according to the first environment sound signal and the third environment sound signal, the first speaker unit emits the first noise cancelling sound signal according to the noise cancelling command.