﻿ What is Microphone Sensitivity?

# What is Microphone Sensitivity?

Microphone Sensitivity, in plain terms, is the magnitude of the volume of sound that a microphone can record for a given signal; basically, it's the "loudness" of the sound that the microphone can pick up. A certain level of sound is played from a source and the microphone records this signal. The amplitude, or intensity, of the signal that the microphone can record is the sensitivity, or gain, of that microphone.

In engineering, the loudness, or sensitivity, is measured in volts, usually millivolts. The sensitivity tells us how much electrical output (in millivolts) a microphone produces for a certain sound pressure level at a certain frequency. If two microphones are subjected to the same exact sound pressure level at a certain frequency and one puts out a higher signal (higher voltage), that microphone has higher sensitivity than the other at that frequency.

Below is a graph showing a visual of Microphone Sensitivity:

This is a graph showing the Microphone Sensitivity of two microphone headsets at a wide range of frequencies. In this graph, you can see the Gain that each headset picks up at each frequency from 20Hz to 20KHz. Both headsets were subject to the same signal, meaning they were subject to the same exact sound pressure level. From looking at this graph, the red line, the NC-181 Headset, has higher gain sensitivity than the blue line, the ANC 750 Headset, at all ranges of frequencies except for the very low frequencies, from about 20Hz to 150Hz. Therefore, overall, spanning the bandwidth of frequencies, the NC-181 has superior microphone sensitivity, or gain, than the ANC 750. Keep in mind, though, that though a microphone headset may have better sensitivity than another one, it doesn't necessarily mean that it's a superior headset. There are still other parameters, or tests, that must be examined, such as the EMI noise a microphone headset picks up or its noise cancellation ability, to conclude which microphone headset is superior.

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