FOCUS: NVH Working toward a noise-free world Squeals occur often in everyday life. We are all familiar with the sound of a worn door hinge and chalk on blackboard, just to name a few. You are probably hearing the high-pitched sound inside your head as you are reading this. They are the result of friction induced vibration with low damping. The automotive industry has been dealing with this challenge for decades. Brake squeal is one of the most common problems for vehicle manufacturers and results in high warranty costs. Most drivers have probably experienced the phenomenon to some degree, but few are aware of the amount of work it requires to eliminate brake noise. Every vehicle requires a different solution. Brake pad insulators, commonly referred to as " shims, " are the primary ABOUT THE AUTHOR The article was written for Update by 25-year SAE member Eric Denys, General Manager Meneta North America, and Chairman of the SAE Brake NVH Standards Committee. UPDATE Eric Denys interfaces with the latest Meneta noise dynos. December 2021 19 Meneta Group