1.The reason why there is a magnet in the headphone is because the sound unit of the earphone can interact with the coil passing through the audio signal through the magnetic field formed by the magnet to convert the audio signal (electrical energy) into sound, so that the earphone diaphragm moves back and forth to vibrate the air to produce sound.
2. The coil inside the headset generates a changing magnetic field through the audio current. The variable magnetic field interacts with the fixed magnetic field, the same polar magnetic field repels each other, and the different polar magnetic fields attract each other. As the intensity of the audio current changes, so does the force of magnetic field interaction, and the sound membrane of the headphones constantly vibrates, resulting in sound.
3. The magnetic field strength of the headset is relatively small, and the impact on the human body is negligible. However, it is recommended not to use the headphones frequently, because if the headphones are carried in a narrow space of the ear canal, it will create a closed space and cause more damage to the eardrum.
Extended Information:
Dynamic earphone principle: At present, the vast majority (about 99%) of headphone earbuds belong to this category, the principle is similar to ordinary speakers, the coil in the permanent magnetic field is connected to the diaphragm, and the coil drives the diaphragm to make sound under the drive of signal current.
There is a magnet in the dynamic earphone, and its main function is to establish a permanent magnetic field. There is also a thin diaphragm on which a coil is fixed and placed in a permanent magnetic field. When the signal current of sound flows through the coil, the coil also generates a magnetic field, which interacts with the permanent magnetic field, and the force is transmitted to the diaphragm.
Because the sound signal current continues to change in size, the magnitude of the two magnetic fields is also constantly changing, so that the silent film vibrates, and the vibration of the diaphragm emits sound.
