What shape is associated with the cardioid microphone pickup pattern?

The cardioid microphone pickup pattern is associated with a heart-shaped design. This characteristic shape indicates that the microphone is most sensitive to sound coming from the front and gradually diminishes its sensitivity to sound originating from the sides, with minimal pickup from the rear. The heart shape effectively illustrates how sound is captured, focusing on a specific direction while rejecting noise from the surroundings. This design is particularly beneficial in live sound and recording environments, as it helps to isolate the desired audio source, reducing background noise and feedback.