Light engine (high frequency)

The sound of a small, high-speed drill used during dental procedures, usually to remove decay and shape tooth structure prior to the insertion of a filling or crown.

The sound of a machine utilizing one or more revolving blades to cut grass, powered by an electric motor, a small internal combustion engine, or by a human pushing the machine.

The sound of a portable mechanical saw which cuts with a set of teeth attached to a rotating chain. Chainsaws are commonly powered by a small two-stroke internal combustion engine.