Your Acer laptop carries decent amount of Bluetooth software which allows you to connect to the headset and do the voice calls. One part of it is an audio driver which introduces a new audio device in the system when headset is connected. Another part is responsible for configuring Skype to talk over this audio device. It works a bit similar to when you plug a USB headset into your computer. In case of voice PSM stream is passed to and from the Bluetooth device, and Bluetooth device performs encoding/decoding and over the air transmission. Victor Zhodzishsky Chief Architect, Bluetooth Software Broadcom Corporation ________________________________ From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Muromachi, Yuka Sent: Tuesday, December 11, 2007 11:20 AM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: Replace WaveRT stream data? 2007/12/12, Muromachi, Yuka <wdmaudio@xxxxxxxxx>: I bought a notebook of Acer Aspire. This notebook contain a miraculous function, which is turn the blue-tooth Audio Device (which is a headphone set) to the on-board audio codec device. Sorry. The details should be: The default device is on-board codec. The skype open default device microphone as input, and open the default device headphone as output. The microphone stream of blue-tooth device will turn to default device input stream and the default output stream will turn to blue-tooth device output.