Sensitivity and frequency response are two common terms used in selecting and using microphones. The sensitivity of the microphone is the signal voltage at the microphone terminals for a given reference sound pressure. When there is no frequency mentioned 1 kHz is assumed. Frequency response is the signal voltage for a given sound pressure across a range of frequencies which is typically 100 Hz to 10 kHz. Frequency response curves can be found on most data sheets and there will be an example further into this presentation. These are two very important terms that need to be thought of with microphones, from design to finished product.