Abstract: Disclosed are dual mode I/O devices and methods for transmission of a short range radio link such as a Bluetooth® link that is a bi-directional real-time audio communication signal that can be over a synchronous circuit-switched transport and an asynchronous packet-switched transport either sequentially or simultaneously. Also disclosed are dual mode wireless headset systems and methods of at least two dual mode I/O devices and more particularly including a wireless audio terminal and an audio gateway for transmission of a bi-directional real-time audio communication signal that can be over a synchronous circuit-switched (SCO) transport and an asynchronous packet-switched (ACL) transport either sequentially or simultaneously. Having both SCO and ACL modes available may allow the user to optimize voice quality or data throughput under different operating conditions. The user may benefit from better Bluetooth®voice quality and may have the flexibility of using either mode depending upon the situation.