There is a weird, constant high-pitched whine/hum that is emitted at all times when the device is plugged in. There doesn’t seem to be impact on its performance, but it may annoy some people. I would advise sticking with it for a while as it is easy to get used to and ignore after a while. Also, the air fryer function make it the best air fryer on the market today. I’ve used every function on the dial and every one works perfectly.