DUDE, there's nothing wrong. You have sensitive ears (like me) and probably could navigate your home in the night without the aid of any lights (assuming you train yourself to do that sonar-bat-thing).
Seriously, though, I have CRT televisions and I hear the same thing (1989 TG-16 + CRT, same noises). I honestly can't tell if it emanates from the speakers on televsion/monitor or somewhere else. Different colors flash on the screen are associated with slightly different pitches/tones of varying (very short, usually) duration.
This question has been asked before, and I supplied my usual non-answer-but-anecdote-instead response. I can't recall if one of the technical gurus here provided a definitive answer.
The fact that you are using an LCD seems to suggest that IF THE SOUND is not generated by the console itself (hey, what do I know, I hear similar high-pitched noises from my laptop), then perhaps their is interference with the audio signal.
I KNOW I DID NOT HELP. But, perhaps you will find solace in the fact that I haven't let it bother me (too much) for the past LONG TIME (damn, I don't even want to type it out).