One usually thinks about a faulty monitor immediately but after researching the topic for a few hours I came up with a better solution that eliminated that background noise completely. The noise is directly related to the brightness setting of the LCD monitor. Reducing the brightness of the monitor will start the buzzing sound while a brightness level of 100 will stop it.

I’m not a technician but I suspect that the noise is coming from the power supplies that power the small fluorescent tubes that are responsible for the backlight. Setting the brightness level to 100 eliminated the noise completely on both LCD displays. It was called Back Light and not brightness in the LCD television’s options.

Setting the brightness to 100 resulted in a very bright computer monitor display which I was able to turn down by using the brightness settings of the video card. The LCD television provided two independent settings for brightness and backlight to adjust the display.