Microphone array having a second order directional pattern

A directional microphone system comprising:

• first, second and third omni-directional microphones, each of the microphones for converting an audible signal to a corresponding electrical signal;
• means for converting the corresponding electrical signal of each of the microphones into a single, multi-order directional signal;
• means for converting the corresponding electrical signal of two of the microphones into a single, first-order directional signal;
• and
• means for summing the multi-order directional signal and the first order directional signal.

A directional microphone system comprising:

• first, second and third omni-directional microphones, each of the microphones for converting an audible signal to a corresponding electrical signal;
• means for adjusting the relative gain of the first, second and third microphones such that the magnitudes are substantially equal;
• means for converting the corresponding electrical signal of each of the microphones into a single multi-order directional signal;
• means for converting the corresponding electrical signal of two of the microphones into a single, first-order directional signal;
• a high pass filter for filtering the multi-order directional signal;
• a low pass filter for filtering the first-order directional signal;
• and
• means for summing the filtered multi-order directional signal and the filtered first order directional signal.

A directional microphone system comprising:

• means for creating a single multi-order directional signal;
• means for creating a single, first-order directional signal;
• and
• means for summing the multi-order directional signal and the first order directional signal.

A method of determining whether a plurality of microphones have sufficiently matched frequency response characteristics to be used in a multi-order directional microphone array, the method including:

• determining the Δp of each of the microphones;
• determining the resonant frequency of each of the microphones;
• and
• determining whether the differences between the Δp's of each of the microphones and the resonant frequencies of each of the microphones falls within an acceptable tolerance.

A directional microphone system comprising:

• means for providing a first order signal representing a first order pattern;
• means for low pass filtering the first order signal;
• means for providing a second order signal representing a second order pattern;
• means for high pass filtering the second order signal;
• and
• means for summing the low pass filtered first order signal and the high pass filtered second order signal.

A method of providing a directional microphone signal comprising:

• providing a first order signal representing a first order pattern;
• low pass filtering the first order signal;
• providing a second order signal representing a second order pattern;
• high pass filtering the second order signal;
• and
• summing the low pass filtered first order signal and the high pass filtered second order signal.

A directional microphone system comprising:

• means for providing a first order signal representing a first order pattern;
• means for low pass filtering the first order signal;
• means for providing a multi-order signal representing a multi- order pattern;
• means for high pass filtering the multi-order signal;
• and
• means for summing the low pass filtered first order signal and the high pass filtered multi-order signal.

A method of providing a directional microphone signal comprising:

• providing a first order signal representing a first order pattern;
• low pass filtering the first order signal;
• providing a multi-order signal representing a multi-order pattern;
• high pass filtering the multi-order signal;
• and
• summing the low pass filtered first order signal and the high pass filtered multi-order signal.

A method of determining whether a plurality of microphones have sufficiently matched frequency response characteristics to be used in a multi-order directional microphone array, the method including:

• determining the Q of each of the microphones;
• determining the resonant frequency of each of the microphones;
• and
• determining whether the differences between the Q's of each of the microphones and the resonant frequencies of each of the microphones falls within an acceptable tolerance.