Words4EV.speak 1.0 (en)

Switching

The switching noise is a high-frequency noise (5-15 kHz), making it sometimes inaudible, low in level and emerging. It has a motor-harmonic or inverse harmonic-motor behavior ; its pitch might increase or decrease when the engine rpm increases. It may be bothering, shrilling or very annoying depending on the engine setting or each one auditive sensibility. It is similar to high-voltage line sound or tinnitus. Switching is a sound from electromagnetic origin, due to pulse width modulation devices.