Polar Pattern
Definition
A graphical representation of a microphone's sensitivity to sound arriving from different directions. Common patterns include cardioid (front-focused, rejects rear), omnidirectional (equal sensitivity in all directions), and figure-8 (front and rear, rejects sides). The choice of polar pattern fundamentally affects how much room sound, bleed, and off-axis coloration a microphone captures.
In Simple Terms
The shape of what your microphone "hears." Cardioid picks up what's in front and rejects the back — best for vocals and single instruments. Omni picks up everything equally — great for capturing a room. Figure-8 picks up front and back but not the sides — used for mid-side recording and interviews.
In Practice
A vocalist records with a cardioid condenser microphone, which captures the voice directly in front while rejecting the room reflections and computer fan noise behind it. An omnidirectional mic in the same position would capture significantly more room ambience.
Common Confusion
Switching polar patterns on a multi-pattern microphone changes more than just the pickup area — it also changes the frequency response, proximity effect behavior, and noise rejection characteristics. Each pattern effectively makes it a different microphone.