Animal Clipper

Is it normal for Oster home dog clippers to be so LOUD?
When a friend’s small poodle died I bought her Oster clipper to trim the hocks on my Aussies. I was expecting a gentle hum. I was not prepared for the loud irritating sound it produced. Heck, my own ears find it unpleasant. My dogs are sure to think so also. The only thing I can think of to compare the sound with is an engraving device when you are marking a piece of personal property. Is this normal? When I go to the grooming salon they don’t seem so loud, and when I clipper animals at the shelter who need a makeover before the adoptathon the hum is no more than an electric shaver for people. Anything I can do to fix this? I’ve already used lubricating oil on the blades as the manual says to do.
you probably just have to tighten the screws. that always happens to mine and that fixes em
Wahl Star Lister Animal Clippers