This portion of the tutorial will discuss microphone packages and package terminology. The sound inlet is the hole in the package that allows sound to reach the microphone sensor. The front chamber is the area between the sound inlet and the sensor membrane. Small front chambers provide better performance, particularly at the high end of the frequency range. The back chamber is the area inside the microphone on the opposite side of the membrane from the sound inlet. The size of the back chamber is a very important factor in determining sensitivity and low frequency performance. The combination for good microphone performance is a small front chamber, which gives good high frequency performance, and a large back chamber, which gives good low frequency performance, high sensitivity, and high SNR.