Which microphone polar pattern is best suited for capturing sound from a single source while rejecting ambient noise?

The microphone polar pattern best suited for capturing sound from a single source while rejecting ambient noise is a cardioid polar pattern. A cardioid microphone primarily picks up sound from the front, while rejecting sound from the rear and sides. This directional sensitivity allows it to isolate the desired sound source, such as a speaker's voice, and minimize the pickup of unwanted ambient noise, such as room reverberation, background conversations, or stage noise. Compared to omnidirectional microphones, which pick up sound equally from all directions, or bidirectional microphones, which pick up sound from the front and rear, cardioid microphones offer superior isolation and are therefore ideal for situations where noise reduction is critical. Within the cardioid family, there are variations like supercardioid and hypercardioid, which offer even narrower pickup patterns and greater rejection of off-axis sound, but they also have a small lobe of sensitivity at the rear, so careful placement is important. For instance, a cardioid microphone would be well-suited for recording a vocalist on stage, minimizing the pickup of instruments and audience noise.