How to Configure the Sound Card to Prevent Echo in Telephony Application Programing Interface (TAPI) Internet Protoco (IP)Telephony Conferences

This article explains how to configure a sound card to prevent echoing in Telephony Application Programing Interface (TAPI) Internet Protocol (IP) telephony conferences by using volume control settings.

The most common cause of echoing in IP telephony conferences is a wrong configuration of sound card settings. All conference participants should use the following procedure to check their sound card settings:

1. Click Start, point to Programs, point to Accessories, point to Entertainment, and then click Volume Control.
2. In the Master Out dialog box, on the menu click Options, and then click Properties.
3. In the Properties dialog box, under Adjust Volume For, click Playback.
4. Under Show the following volume controls, confirm that the Wave and Microphone check boxes are selected. If there is a check box for Digital Recording Control, confirm that it also is selected. You may have to scroll down the window in order to see these settings.
5. Click OK, and then close the Properties dialog box.
6. In the Master Out dialog box, click to select the Mute check box in the Microphone column if it is not already selected. This prevents speech from being echoed locally (played back on the speaker's workstation). If there is a column for Digital Recording Control, click to select the Mute check box there also.
7. If the voices of all other conference participants are too loud, drag the Volume Control slider downward. If their voices are too quiet, drag the slider upward.
8. On the Options menu, point to Properties, and then click Recording.
9. Click to select all of the check boxes in Show the following volume controls. (You may have to scroll the window down in order to see all of the check boxes.)
10. Click OK.
11. In the Master Out dialog box, click to select Mute in all of the columns except for Microphone, if they are not already selected. Confirm that Mute in Microphone is not selected. This allows your speech to be sent to the conference, but will prevent other sounds, including those of other conference participants, from being transmitted from your computer.
12. If other conference participants find sound from the workstation to be too loud, adjust the Microphone slider downward. If the sound is too quiet, adjust the Microphone slider upward.
    
    NOTE: One incorrectly configured workstation sound card can cause audio problems or echoes for all other conference participants. Replacing conference participants' speakers with headsets or replacing participants' microphones with echo-canceling microphones might also eliminate echo.