@TP-Link I have the exact same issue on all of my KL110B bulbs. Is there a fix?

@TP-Link 

Hi,

In answer to your questions:

1. I bought three KL110B on Dec 1 2020, all three made these noises from the start. I noticed it immediately.

2. See attached. These are amplified samples from my phone (some background noise from my neighbours talking too). The first is with the light on and the second off. Both with mains power on. It's a high pitched constant sound plus a frequent chirping kind of noise. If I turn off mains power there is no noise.

3. I have done a soft and hard reset and can still hear it just powering on without setting up.

Similarly I have four KP105 smart switches I bought around the same time, from a different retailer, all of these make a similar sound though different frequency that I couldn't pick up on a phone.

To me all of these sound similar to some mobile chargers I've got if I listen close up. It sounds to me like switching power supply noises.

The lights are more of a problem as they are more noticeable in the quiet at night. This means for the bedroom light I have to physically turn off the light at the switch. It's not loud and sometimes I'm okay with it, but it's just I expected a light to be silent especially when off.

Hi,

I notice the same from my KL110B, purchased from Amazon UK in early January, hardware version 1.0 firmware version 1.8.11.

Previously I had in that same ceiling light socket an LB110 which did not make this noise (LB110 hardware version 1.0 firmware version 1.8.6).

It is indeed very annoying when the room is silent, despite my aged ears, causing me to switch off at the wall making it useless.

Could it be 2.4ghz vs 5ghz wifi? I can't tell which network it is on nor see how to change it.

@TP-Link Hi,

The noise happens whether the light is illuminated or not, if there is power to the light fitting (from the wall switch) then the bulb is beeping.

Yes, it has made this noise since I purchased it in January.

It functions fine, but makes a noise, and in a silent room stops me sleeping.

It is disappointing that it does this when the previous bulb I had from you did not.

If you have any suggestions on how to stop the beeping I am happy to try, otherwise I will return for a refund.

It's not a dimmer switch buzz. That's caused by the dimmer on the mains affecting the voltage signal. Shouldn't use mains dimmers on smart bulbs anyway as the dimmable feature is within the bulb itself by turning the LEDs on and off at different rates. 

The issue is a sound from within the circuitry that is always on to power the WiFi and smart functions whether the light is on or off, unless the mains itself is off. Its a chirping sound rather than buzz.