When a new trimmer or clipper suddenly starts to become louder it is normally due to a couple of things related to blade friction or because a screw is a little loose. Try the following to see if they will help resolve the issue. (They may seem super basic, but you'd be surprised at how often this resolves the noise problem.)
• Please carefully clean the blades. Please check for any stubborn debris or hairs stuck in the wrong place. A few hairs that jam at the wrong spot lead to a louder noise due to the abnormal friction and contact.
• Please make sure the blades are oiled with a couple drops of the clipper oil. Spread the oil to the blades and blade housing with a small clipper brush. Wipe off any access. The first symptom of insufficient oil on the blades is louder operation. When you turn on the device again, allow a minute or so for the oil to further spread.
• Please make sure that all the screws are properly tightened (not overly tight though). Although these clippers come straight from the manufacturer to us then to you, it is possible that a screw may need to be further tightened after its very first uses (that jostle a lose screw more free).