Dual-use bilateral microphone array

1. An apparatus comprising:

a first earphone having a first microphone array, providing a first set of microphone signals, and a first speaker;

a second earphone having a second microphone array, providing a second set of microphone signals, and a second speaker; and

a processor receiving the first set of microphone signals and second set of microphone signals, and configured to:

apply a first set of filters to combine the first and second set of microphone signals to generate a far-field signal that is more sensitive to sounds originating a short distance away from the apparatus than to sounds close to the apparatus;

provide the far-field signal to the speakers for output;

apply a second set of filters to combine the first and second set of microphone signals to generate a near-field signal that is more sensitive to voice signals from a person wearing the earphones than to sounds originating away from the apparatus; and

provide the near-field signal to a communication system.

2. The apparatus of claim 1 , wherein the first microphone array and second microphone array are physically arranged to optimize detection of sounds a short distance away from the apparatus.

3. The apparatus of claim 1 , wherein the processor is further configured to:

use a third set of filters, different from the second set of filters, to combine the first and second set of microphone signals to generate a second near-field signal that is more sensitive to voice signals from the person wearing the earphones than to sounds originating away from the apparatus; and

provide the second near-field signal to the speakers for output.

4. The apparatus of claim 1 , wherein applying the first set of filters comprises:

applying separate filters to each signal from each of the first and second sets of microphone signals to produce a first set of filtered signals;

summing the signals of the first set of filtered signals to produce a first summed signal; and

applying an equalization filter to the first summed signal to generate the far-field signal.

5. The apparatus of claim 1 , wherein the processor is further configured to generate the far-field signal and provide the far-field signal to the speakers by:

combining the first and second set of microphone signals, using a third set of filters, different from the first set of filters, to generate a second far-field signal that is more sensitive to sounds a short distance away from the apparatus than to sounds close to the apparatus;

providing the first far-field signal to the first speaker; and

providing the second far-field signal to the second speaker.

6. The apparatus of claim 1 , wherein the processor comprises a far-field array sub-processor for applying the first set of filters, and a communication sub-processor for applying the second set of filters, and wherein the sub-processors are configured to generate the near-field signal by:

in the far-field array sub-processor,

summing signals corresponding to a first one of the microphones in the first array and a first one of the microphones in the second array to form a combined front microphone signal, and

summing signals corresponding to a second one of the microphones in the first array and a second one of the microphones in the second array to form a combined rear microphone signal; and

in the communication sub-processor,

filtering the combined front microphone signal to form a filtered combined front microphone signal,

filtering the combined rear microphone signal to form a filtered combined rear microphone signal, and

combining the filtered combined front microphone signal and the filtered combined rear microphone signal to form a directional microphone signal;

the near-field signal comprising the directional microphone signal.

7. The apparatus of claim 1 , wherein the processor is further configured to operate the first and second sets of filters simultaneously.

8. The apparatus of claim 1 , wherein:

the far-field signal is more sensitive to sounds originating in a first direction than to sounds originating in other directions, and

the processor is further configured to:

apply a third set of filters to combine at least the first set of microphone signals to generate a first anti-noise signal that will cancel sounds at the first earphone when output by the first speaker; and

apply a fourth set of filters to combine at least the second set of microphone signals to generate a second anti-noise signal that will cancel sounds at the second earphone when output by the second speaker.

9. A method comprising, in a processor:

receiving, from a first earphone having a first microphone array, a first set of microphone signals;

receiving, from a second earphone having a second microphone array, a second set of microphone signals; and

combining the first and second set of microphone signals, using a first set of filters, to generate a far-field signal that is more sensitive to sounds originating a short distance away from the first and second earphones than to sounds close to the first and second earphones;

providing the far-field signal to first and second speakers in the respective first and second earphones for output;

combining the first and second set of microphone signals, using a second set of filters, to generate a near-field signal that is more sensitive to voice signals from a person wearing the earphones than to sounds originating away from the first and second earphones; and

providing the near-field signal to a communication system.

10. The method of claim 9 , further comprising, in the processor:

combining the first and second set of microphone signals, using a third set of filters, different from the second set of filters, to generate a second near-field signal that is more sensitive to voice signals from the person wearing the earphones than to sounds originating away from the apparatus; and

providing the second near-field signal to the speakers for output.

11. The method of claim 9 , wherein applying the first set of filters comprises:

applying separate filters to each signal from each of the first and second sets of microphone signals to produce a first set of filtered signals;

summing the signals of the first set of filtered signals to produce a first summed signal; and

applying an equalization filter to the first summed signal to generate the far-field signal.

12. The method of claim 9 , wherein generating the far-field signal and providing the far-field signal to the speakers comprises, in the processor:

using a third set of filters, different from the first set of filters, to combine the first and second set of microphone signals to generate a second far-field signal that is more sensitive to sounds a short distance away from the apparatus than to sounds close to the apparatus;

providing the first far-field signal to the first speaker; and

providing the second far-field signal to the second speaker.

13. The method of claim 9 , wherein generating the near-field signal comprises:

in a far-field array sub-processor,

summing signals corresponding to a first one of the microphones in the first array and a first one of the microphones in the second array to form a combined front microphone signal, and

summing signals corresponding to a second one of the microphones in the first array and a second one of the microphones in the second array to form a combined rear microphone signal; and

in a communication processor,

filtering the combined front microphone signal to form a filtered combined front microphone signal,

filtering the combined rear microphone signal to form a filtered combined rear microphone signal, and

combining the filtered combined front microphone signal and the filtered combined rear microphone signal to form a directional microphone signal;

the near-field signal comprising the directional microphone signal.

14. The method of claim 9 , further comprising operating the first and second sets of filters simultaneously.

15. The method of claim 9 , wherein the far-field signal is more sensitive to sounds originating in a first direction than to sounds originating in other directions, and the method further comprises:

applying a third set of filters to combine at least the first set of microphone signals to generate a first anti-noise signal that will cancel sounds at the first earphone when output by the first speaker; and

applying a fourth set of filters to combine at least the second set of microphone signals to generate a second anti-noise signal that will cancel sounds at the second earphone when output by the second speaker.