Annoying buzzing noise when on off/standby
922140
For some reason mine makes a weird buzzing noise when its off but plugged in that comes from the plug, really annoying when trying to sleep so I had to put a smartplug to toggle it on and off

the buzzing noise stops when the light is on and the different settings work perfectly
997097
I believed the 5 star reviews and the reviews about the light not humming/buzzing when used with the dimmers. The light is bright and is good but there is a significant level of humming noise that will annoy anyone if used in a bedroom, living room, etc., I tried it with the Lutron MACL-153M-WH Maestro 150-Watt Multi-Location CFL/LED Digital Dimmer and also Legrand LED dimmer, the buzzing is still there. I will be returning the bulbs as its no good when you have an annoying buzzing when switched on. I hope Hyperikon looks into this and addresses this issue.
1492245
The unit had an annoying electrical humm or low buzzing sound that is audible when near.  I will be requesting a replacement in hopes it was just a bad unit and try again.  Will report back.
4398429
I got this because I wanted more space and yet more power too. It works fine but causes a weird buzzing sound and a pop on my speakers every second. It is only this way when I have the power plugged in with the power adaptor. Other then that it is as I expected.
2933810
Product seems to work as advertised. However, there is a low buzz from the speaker when connected to this converter output.
The speaker works fine from other sources, but only with this converter it makes a buzzing noise at high volumes. It is almost inaudible at lower volumes, but distinct at higher volumes. I am not sure if this "buzz" is supposed to happen but it is distracting.
4506768
Plugged in, it makes a high pitched noise. Couldn't find anyone else with a similar problem but it is probably a one time thing.
3796189
I wanna love this, so very much, but most unfortunately I hear a very high pitched buzzing noise with this fan, especially on anything lower than very strong, high settings...SIGH. I saw someone else mentioned their kid had that issue with it too and even explained why... But I'm afraid it's not a common enough issue for them to fix it, sadly, but it'd be so incredibly awesome and useful if they did!!!!! I've always wanted a dial like that for fans/AC, as it's often too little or too much. I have erythromelalgia (aka burning alive) so I need fans all the time and am also super sensitive to sounds... I was so ultra excited to FINALLY have a SUPER STRONG portable fan with this (the DC model can be used with a portable rechargeable battery as well as plugging in as normal), but it's hard for me to use with the high pitched tone. My dad can't hear it. My dial can be a little too easy to move when not meaning to, also, but.....great idea! Needs improvement...
2636360
After installing without testing we soon realized this thing was annoying.  It started beeping obnoxiously until we unplugged it.  This happend with the unit even in standby mode.  TI seemed the kitchen timer that is built into it was stuck on.  Manufacturer suggested returning it, so we did and went after a different brand.
2011079
The light flickers while charging and something inside the pad is making a rapid beeping sound. It's quiet, but when it's next to me while I'm trying to sleep it's extremely annoying. Feels cheap.
3660171
works perfectly, except for the beeping noise it makes when you select every operating mode. Gets annoying in the middle of the night. Other than that, works as expected. Easy to install.
3951606
Noisy startup.  This is annoying if using power saving mode at night when the startup rumble comes on every few minutes.  This seem to be due to the unit using the same fan to circulate air over the temperature sensor.  Noise level acceptable otherwise during normal operation.
231941
Good lightning but annoying buzzing sound that gets louder over time.  Not buying these again.
4882087
Have to unplug and plug back in every single time i turn my pc off or put it into sleep mode
116365
Does what its supposed to, however when our phones or tablets are not charging the device makes a faint but high pitched noise.  If you walk in and out of the room quickly you'll probably never hear it however, if your trying to sleep or read, it can be extremely distracting, sadly I had to unplug all my wireless chargers and put them away in drawers.  not sure if its just cheap build quality or bad design.  Buyer beware.
995714
The device emits a high pitched noise whenever any device is charging from either of the USB hubs.

The device works as advertised but since I was planning on using it in a location where I am able to hear the noise I am returning the unit.
1468142
This charger has worked well for the 3 months or so that I have been using it. The LED used to indicate that AC power is connected is not too bright and I like that. The overall build quality appears a little bit cheap relative to the original charger that came with my ASUS laptop. The thing that drives me nuts about this charger though is that it emits a high frequency buzzing noise (~12kHz) every time there is any kind of loading. So if the laptop is just sitting there fully charged then no noise but as soon as I move the mouse the charger responds by squealing. It is definitely loud and noticeable even when a TV is on at a reasonable volume. I find myself fixating on the damnable buzzing noise as I am using my laptop. I would only reccomend this charger to someone I hated because I know that it would slowly drive them insane.
4916379
Update: now when it turns on there will be 2 buzzing sounds like it is under some kinda interference. All sounds that come out thereafter are somewhat distorted. So disappointing.

Hook can be designed to open up easier. No lower back feet to straighten it when being hung and rested against a surface. No USB-C in 2018? Very water-proof. Decent battery usage but slow-charging.