Earphone sensitivity refers to the sound pressure level that the earphone can emit when 1 milliwatt of power is input to the earphone (the unit of sound pressure is decibels, the greater the sound pressure, the greater the volume), so generally the higher the sensitivity and the lower the impedance, the earphone The easier it is to make a sound, the easier it is to drive.
Generally speaking, the sensitivity of the earphone is actually the sensitivity level of the earphone. It is the sound pressure level generated by the earphone coupled to the artificial ear (dummy head) when the electric power of 1mW is applied to the earphone. The power of 1mW is the frequency The standard impedance of the earphone at 500Hz is calculated based on it.
The unit of sensitivity is dB/mW, and another uncommon one is dB/Vrms, which is the sound pressure level generated when a voltage of 1Vrms is applied to the earphone. High sensitivity means that the power required to reach a certain sound pressure level is small. The sensitivity of moving coil headphones is generally above 90dB/mW. If you choose headphones for walkmans, the sensitivity should be around 100dB/mW or higher.
Sensitivity is also called sound pressure, sound pressure or sensitivity, and English is Sensitivity. Sensitivity, as the name suggests, refers to how much volume the headset will produce under a certain input power. The higher the sensitivity, the lower the power required. Therefore, sensitivity is inversely proportional to impedance. If the sensitivity is high and the volume is turned up slightly, the sound will be loud.