🔍 Key Concepts

• How a permanent magnet and diaphragm interact in a telephone earpiece/headset • What “sensitivity” means in an audio receiver (how easily it converts small electrical signals into sound) • What kinds of distortion or harmonics a magnetic audio device might create

💭 Think About

• Think about the primary, basic purpose of the permanent magnet in a headphone earpiece: what must it provide for the diaphragm to move in response to the signal? • Does adding a permanent magnet normally change the entire frequency response curve, or is its main job something simpler and more fundamental? • If the magnet and diaphragm system is non‑linear, what effect would that have on harmonics, and is the magnet mainly there to eliminate those, or to create a steady magnetic field?

✅ Before You Answer

• Be clear on the main, fundamental role of the permanent magnet in a magnetic headset receiver, before considering side effects like frequency response or harmonics. • Ask whether each option describes a primary function or a possible side effect; focus on what the magnet absolutely must do for the device to work. • Verify whether it is realistic that one simple component (the permanent magnet) would intentionally be designed to achieve all three detailed effects at once.