| 摘要 |
An earphone microphone is constituted of a main unit and an insert portion which are united in an L-shape. Two receivers are attached to the external surface of the main unit and exposed externally of a user's ear, whilst one receiver is attached to a distal end of the insert portion that is inserted into a user's external auditory canal and disposed opposite to a user's eardrum. A signal processor produces a difference signal between the output signals of two receivers exposed externally of the user's ear. The difference signal is subjected to high-pass filtering and subsequently added to the output signal of the receiver disposed inside the user's external auditory canal, thus producing a sound signal representing a user's sound. The sound signal includes a sufficient number of frequency components (e.g. frequency components higher than 3 kHz) prerequisite for discriminating the user's sound. |
