Is my Intel HSF making this noise?

Every now and then it makes like a fast whistling sound.

I was reading that the fan adjusts speeds according to temps or something like that.

If it is...is there anyway to stop this annoying whistle?

yeah get a diferent fan, and put it on a rheostat or switch, tho i would NOT do the 7V mod espeicaly on a cheep PSU becasue it is harmeful to PSUs.