Original sentence: BRIAN RULES
Edited sentence: An example of a nondirectional microphone is the round black eight ball.An omnidirectional (or nondirectional) microphone's response is generally considered to be a perfect sphere in three dimensions.As with directional microphones, the polar pattern for an "omnidirectional" microphone is a function of frequency.Being pressure-sensitive they can also have a very flat low-frequency response down to 20 Hz or below.In the real world, this is not the case.Omnidirectional microphones, unlike cardioids, do not employ resonant cavities as delays, and so can be considered the "purest" microphones in terms of low coloration; they add very little to the original sound.Pressure-sensitive microphones also respond much less to wind noise than directional (velocity sensitive) microphones.The body of the microphone is not infinitely small and, as a consequence, it tends to get in its own way with respect to sounds arriving from the rear, causing a slight flattening of the polar response.The wavelength of sound at 10 kHz is little over an inch (3.4 cm) so the smallest measuring microphones are often 1/4" (6 mm) in diameter, which practically eliminates directionality even up to the highest frequencies.Therefore, the smallest diameter microphone will give the best omnidirectional characteristics at high frequencies.This flattening increases as the diameter of the microphone (assuming it's cylindrical) reaches the wavelength of the frequency in question