The pattern on a Blue Yeti is defined by the shape of the space around the microphone where it is most sensitive to sound. In the Cardioid pattern, it is like a heart. The Stereo pattern is similar, but the direction of the sound is also registered. Bidirectional is like a figure of eight, with the lobes stretching in front and behind the Yeti. But the omnidirectional pattern is like a circle, with the Yeti equally sensitive to sound in all directions.