Hi. @mvutrinh 

It’s hard to tell from the video, but it doesn’t jump out as sounding abnormal.

Here’s a quick test you can do on the perform:

Scale the fan speed up and down using the remote and the sound should move up and down relatively smoothly in a gradient.

The sounds to listen for would be a whine/whistle sound (usually indicated of a filter being placed incorrectly) or a grinding noise (which would be a motor alignment issue needing a repair).

Further support for both can be found through our online support, simple use our Dyson Support link to get started. 

Once here, navigate to the 'Support' option in the top navigation bar and select your machine from the on-screen options. 

Adam

That is very much not normal. That sounds like a motor issue to me, I’d get it swapped out or repaired if you can