Abstract: A communication device (203) can include a external data port (110) for at least data transfer and audio transmission and a switchable radio frequency protection circuit (205, 300, 400 or 500) that switches in a resonant circuit or filter circuit (312, 322, 412, 422, 512, or 522) upon detection of an audio transmission and switches out the resonant circuit or filter circuit upon detection of data transfer over the external data port. The switchable protection circuit include a computer processing unit controlled switching device (316) or a hardware identifier controlled switching device (314) or both. The communication device can further include data plus (+) and data minus (?) lines for audio receive and audio transmit. The communication device can also be a laptop for example. The external data port can be a multiplexed port supporting at least data transfer and audio and optionally battery charging.