Polycom 3725-22724-003/A - Manual (Page 5)

Selecting Audio and Video Devices for Use with Polycom PVX
5
Choosing and Configuring Audio Input Devices
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.
Choosing an Audio Input Device
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:
Audio Input Device Advantages Disadvantages
Webcam’s built-in
microphone • 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
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).
Laptop computer’s
built-in microphone • Does not require an external
microphone
• Does not occupy additional desk space
• 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.