Headphone sensitivity refers to the sound pressure level that the earphone can emit when inputting 1 milliwatt of power to the earphone (the unit of sound pressure is decibels, and the higher the sound pressure, the greater the volume). Therefore, the higher the sensitivity and the lower the impedance, the easier it is for the earphone to emit sound and drive.
The unit of sensitivity is dB/mW, and another uncommon unit is dB/Vrms, which is the sound pressure level generated when a voltage of 1 Vrms is applied to the earphone. High sensitivity means that the power required to achieve a certain sound pressure level is small. The sensitivity of dynamic earphones is generally above 90dB/mW. If you choose earphones for your walkman,
The sensitivity is preferably around 100 dB/mW or higher.
