The "polar pattern" of a microphone indicates its sensitivity to sounds arriving from different directions. Omnidirectional microphones "hear" equally well in all directions while all others prefer sound from one (unidirectional) or two (bidirectional) directions. The polar diagram shows the three-dimensional "hearing performance" of a microphone as a single curve. It is sufficient to plot only one half of the curve (0° through 180°) since the other half (180° through 360°) is symmetrical. In this way, the directivity can be shown for several different frequencies (broken, dotted, solid lines).
