good LEDs with swabs

Due to the compact dimensions, my 25 W halogen lamps were replaced by these LEDs. Brightness adjusts, on the color temperature slightly colder than the halogen bulbs.
As a small flaw, I would note that the LED's growl a little. Since I have all 4 installed in a lamp with metal housing is now, perhaps by design, to hear a slight humming sound. At the "village" where the lamp is installed, the hum is to get over, the living room or study, it would bother me.