EIN is becomming a common method for specifying noise in audio equipment. This is a computed figure equal to the noise measued at some gain setting, minus the gain. For example, if a microphone preamplifier puts out -85dBV noise when set for 40dB of gain, the EIN is -125dBV. Note that, while -125dBV seems better than -85dBV, both figures represent the same amount of noise.