Polycom 3725-22724-003/A manual Choosing and Configuring Audio Input Devices

Selecting Audio and Video Devices for Use with Polycom PVX

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	• Does not require an external	Some webcams may experience the following:
microphone	microphone	•	Limited audio quality
	• Does not occupy additional desk space
			Audio is comparable to traditional
	• Distance between microphone and		telephone quality.
	speakers is usually sufficient to avoid	•	Slower computer function
	interference with audio quality
			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	• Does not require an external	•	Limited audio quality
built-in microphone	microphone		Audio is comparable to traditional
	• Does not occupy additional desk space		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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