Distortion caused by RF pickup on the microphone cable
Changes in oscillator frequency caused by mechanical vibration✓Bonne réponse
Excess loading of the microphone by an oscillator
Explication
A microphonic is a change in circuit behavior produced by mechanical vibration or shock. In an oscillator, vibration moves component parts slightly, varying capacitance or inductance and shifting the output frequency, which is heard as a warble or thump.