| 摘要 |
A listening device for presenting at least one audio signal to a user comprises a first ear piece and a second ear piece, each of the first ear piece and the second ear piece including at least one speaker and each being adapted to block substantially all external sounds from entering an ear of a user. The device further comprises a microphone for sensing a first audio signal and a differential amplifier coupled to the microphone for amplifying the first audio signal. The differential amplifier is coupled to a first electrical ground. A switching arrangement coupled to and receiving a second audio signal from an external audio source and the external audio source having a second electrical ground that is electrically distinct from the first electrical ground. The switching arrangement is further coupled to the differential amplifier, the first ear piece, and the second ear piece, the switching arrangement being adapted to select at least one of the first audio signal and the second audio signal for transmission to the first ear piece and at least one of the first audio signal and the second audio signal for transmission to the second ear piece. |
