The sound is most likely acoustic feedback caused by wrong speaker settings. Check that the microphone for the speaker is disabled:
- Right click speaker symbol in systray (small icon next to the time/date)
- Choose playback devices
- Select the "Speakers, Realtek High Definition Audio"
- Click properties
- Open the tab "Levels"
- Mute the microphone by clicking on the speaker icon
- Make sure that the "Microphone, Realtek High Definition Audio" is set as Default Device.
- NOTE! IF the above doesn't fix the problem - go to Microphone properties - Listen tab - make sure that the box that says "Listen to this device" is Not ticked in.
There is no reason to have microphone enabled for the speaker as you have the settings in recording devices for that.