Depending on their design and construction, microphones respond to sound coming from different directions with varying degrees of sensitivity. A plot or graph of this response is called a polar pickup pattern. Looking at a mic's polar pattern will tell you how well it will pick up or reject sound from certain directions.

The most common polar pattern is "cardioid" (heart-shaped). The graph of the pickup pattern is shaped somewhat like a heart. Cardioid mics pick up sound well from the front and offer good rejection of sounds from the rear. "Supercardioid" and "hypercardioid" offer a narrower pickup angle in the front, rejecting more sound from the sides, but they also pick up more sound from the rear.

An omnidirectional mic will pick up sound equally well from any direction. A bidirectional mic (also called a "figure 8") will pick up sound from the front and back, but reject sound from the sides.