Employer Identification Number. The tax identification number provided by the Federal Government to each entity that applies. Same as “Federal Tax Identification Number.” Get your EIN.

See federal employer identification number.

(Employer Identification Number) A unique number assigned by the Internal Revenue Service to every employer in the United States for the purposes of identification. Similar in purpose to the Social Security Number assigned to individuals.

Employer Identification Number is issued by the Federal Government to businesses for tax purposes. A Social Security Number may be used as an EIN for some businesses.

Equivalent Input Noise. The amplitude of internal noise created by a hearing aid

Equivalent Input Noise. A rating of the overall noise performance of an amplifier (typically a microphone preamplifier). Basically, this is a measure of how much noise a mic preamp will add to a microphone's signal. Measurements are normally made with a 150 Ohm resistor on the preamp to simulate the load a mic would present. The theoretical limit on EIN is -130.0 to -131.8 dBm (the thermal noise generated by the resistor). When comparing this spec, keep in mind that larger negative values are better (i.e. -124 is better than -118). But don't place TOO much weight on this spec, most current EIN specs are infinitesimally small (can you REALLY hear the difference between -120 dBm and -122 dBm??)

Equivalent Input Noise. The measurement of the noise in a mixer's pre-amps.