I have compatible, dimmable LED light bulbs for my recessed fixtures and they are the correct watts. However, when on, one of the recessed lights makes a distinct but faint ringing noise. This is the case in two separate rooms. Any idea what is causing this?
Answers: Yes, this is most definitely a ringing noise. Yes, they are LED bulbs. In each of the two rooms which have several fixtures, only one makes the noise.
The current regulators in LED lamps run at high frequencies, and the transformers inside can make a high-pitched whine or hiss due to magnetostriction. In many lamps, the transformers are "potted" in plastic to reduce that noise, but the potting compound might not have been applied evenly. If the lamps are easily changed (e.g., a bi-pin replacement for fluorescent lamp, or an Edison-base replacement for an incandescent), try another lamp, and put the noisier ones in a location that will not matter, e.g., garage or outside fixture.
