Polycom PVX Supplementary Manual page 5

Selecting Audio and Video Devices for Use with Polycom PVX
Choosing and Configuring Audio Input Devices
Choosing an Audio Input Device
Audio Input Device
Webcam's built-in
microphone
Laptop computer's
built-in microphone
Note that some special versions of Polycom PVX provide only the video
portion of calls, while other devices handle audio. This section does not apply
to these special video-only versions of Polycom PVX.
Polycom PVX offers you the flexibility of choosing from a number of different
audio input devices. You can use the webcam's built-in microphone (if your
webcam includes one), your computer's built-in microphone, an external
analog microphone, or a headset.
The advantages and disadvantages of each of these audio input devices are
listed in the following table:
Advantages
• Does not require an external
microphone
• Does not occupy additional desk space
• Distance between microphone and
speakers is usually sufficient to avoid
interference with audio quality
• Does not require an external
microphone
• Does not occupy additional desk space
Disadvantages
Some webcams may experience the following:
• Limited audio quality
Audio is comparable to traditional
telephone quality.
• Slower computer function
The camera's built-in audio echo canceller
may cause additional CPU load.
• Extended audio delay
This is caused by the camera's built-in
audio echo canceller. It results in a loss of
synchronization between the video and
audio, also known as a "lip sync" problem.
• Problems with the Windows® XP echo
canceller
This can be caused by routing audio input
and output through different devices.
• Louder than expected far site sound
• Ineffective audio echo cancellation
This occurs in calls using cameras with
sensitive microphones (such as the
Logitech QuickCam Pro 4000).
• Limited audio quality
Audio is comparable to traditional
telephone quality.
• Possible feedback or echo
The structure of the laptop and low quality
of most laptop speakers can cause
problems that the Windows XP echo
canceller cannot correct.
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