That's interesting, I've been converting over to LED lamps, but that seemed to aggravate my migraines a bit and converted back to halogen filament lamps in work and living areas, which now seem fine. LED's are all basically blue and the colour temperature is determined by the filter, so there is still a substantial amount of blue in the spectrum even after filtering to get 2700K and it can be sensitive for certain people apparently, unfortunately, I seem to be one of them.
In answer to your question, yes, I have come across it, in fact I have LED spotlights in my bathroom from B&Q and they buzz. They are not too bad and I'm not that concerned because we are not in the bathroom long enough to annoy, my wife first noticed it, she can hear things that are not there, but she is correct on this occasion because I can hear them if I listen carefully.
I thought it might have been the switch mode power supply feeding them, but I've been in the loft to check and it wasn't that. One of the jobs while I was up there was to put filtering and the back of each lamp as they were creating merry hell with my shortwave radio reception with noise.
I won't be getting them from B&Q in future, I'll look at the Philips or Compton lamps that I've used in the past without any problems. No disrespect to B&Q because they supply some pretty good stuff, but lamps, no.