Gear noise is a common evil any gear manufacturer must live with. It is often low enough not to be a major problem but, at times, gear whining may appear and then, tracking the source and, especially, curing the ill can be tricky at best.
Lately, the use of asymmetric gears in automotive and other applications is an upcoming trend, though few applications
are known to have asymmetric teeth. However, an increased interest in asymmetric gears can be seen. Many companies have started to design and test such applications.