In the microphone specification, the impedance value (in ohms) is listed. In the microphone field, generally, lower than 600 ohms is a low impedance; between 600 and 10,000 ohms is a medium impedance; and above 10,000 ohms is a high impedance. For general microphone design and practical use, the input impedance of the connected load (amplifier) is usually larger than the microphone output impedance without impedance matching. If the strong match is required, it will affect the microphone's frequency response and cause distortion, especially at higher sound pressures. However, some dynamic microphones or ribbon microphones have the effect of considering or requiring the damping provided by the load impedance. In this case, the specific load impedance must be used to achieve the best effect.