Method and device for acute sound detection and reproduction

1. A method for acute sound detection and reproduction, the method comprising:

measuring an external ambient sound level (xASL) using a microphone wherein a processor applies signal processing to condition and compensate a signal from the microphone and outputs a processed signal;

estimating a background noise level (BNL) from the processed signal;

storing the processed signal in an audio buffer;

identifying and measuring at least one peak level (SPL) in the processed signal stored in the audio buffer;

subtracting the estimated background noise level (BNL) from the measured at least one peak level (SPL) to generate a SPL-BNL difference;

comparing the SPL-BNL difference to a first predetermined threshold wherein an acute sound has been detected when the SPL-BNL difference is greater than the first predetermined threshold;

estimating a proximity of the acute sound by performing a cross correlation between at least two microphones with the at least one processor, wherein the at least two microphones includes the microphone for measuring the external ambient sound level and identifying a peak in the cross correlation; and

upon detecting the acute sound and a time lag in the acute sound between the at least two microphones, reproducing the acute sound with an ear canal receiver after determining the acute sound was not a user-generated sound.

2. The method of claim 1 , wherein the step of estimating a proximity further comprises determining a direction from the time lag.

3. The method of claim 1 , wherein the SPL-BNL difference is negative and wherein a hysteresis unit is configured to determine if the acute sound was previously detected.

4. The method of claim 3 wherein the acute sound is coupled to an ear canal receiver when the hysteresis unit determines if the processor had activated a pass-through mode.

5. The method of claim 3 wherein the acute sound is not coupled to the ear canal receiver when the hysteresis unit determines if the processor had not activated a pass-through mode.

6. The method of claim 3 further including a step of comparing the at least one peak level (SPL) to a second predetermined threshold when the SPL-BNL difference is greater than the first predetermined threshold wherein the acute sound is indicated when the SPL is greater than the second predetermined threshold.

7. The method of claim 6 , wherein the hysteresis unit is configured to determine if the acute sound was previously detected when the SPL is less than the second predetermined threshold.

8. A system configured for acute sound detection and reproduction, comprising:

a microphone used for measuring an external ambient sound level (xASL);

a memory containing computer instructions;

one or more processors coupled to the memory, the one or more processors configured when executing the computer instructions to perform operations comprising:

estimating a background noise level (BNL);

storing an external ambient sound in an audio buffer wherein the audio buffer accumulates the external ambient sound over a predetermined time period;

identifying and measuring at least one peak level (SPL) stored in the audio buffer:

subtracting the estimated background noise level (BNL) from the measured at least one peak level (SPL) identified in the audio buffer to generate a SPL-BNL difference;

comparing the SPL-BNL difference to a first predetermined threshold wherein an acute sound has been detected when the SPL-BNL difference is greater than the first predetermined threshold;

detecting a proximity of the acute sound to determine if the acute sound was user generated; and

passing the acute sound to an ear canal receiver if the acute sound was not user generated.

9. The system of claim 8 , further including the steps of:

estimating a proximity of the acute sound by performing a cross correlation analysis by at least two microphones;

identifying a peak in a cross correlation during the cross correlation analysis;

identifying a time lag in the acute sound between the at least two microphones; and

determining if the acute sound was user generated.

10. The system of claim 9 wherein the step of estimating the proximity further comprises determining a direction from the associated time lag.

11. The system of claim 8 wherein the SPL-BNL difference is negative and wherein a hysteresis unit is configured to determine if the acute sound was previously detected.

12. The system of claim 8 , further comprising computer instructions which when executed by the processor performs the operation of measuring an internal ambient sound level (iASL) due to residual ambient sound within the ear canal at least partially occluded by the earpiece.

13. The system of claim 12 wherein monitoring the change in the xASL comprises monitoring a high frequency change between the xASL and the iASL.

14. The system of claim 8 further including a step of comparing the at least one peak level (SPL) to a second predetermined threshold when the SPL-BNL difference is greater than the first predetermined threshold wherein the acute sound is indicated when the SPL is greater than the second predetermined threshold.

15. A system configured for acute sound detection and reproduction, comprising:

at least two microphones including a microphone used for measuring an external ambient sound level (xASL);

a memory containing computer instructions;

one or more processors coupled to the memory, the one or more processors configured when executing the computer instructions to perform operations comprising:

estimating a background noise level (BNL) from the external ambient sound level (xASL);

storing an external ambient sound in an audio buffer wherein the audio buffer accumulates the the external ambient sound over a predetermined time period;

identifying and measuring at least one peak level (SPL) in the processed signal stored in the audio buffer;

comparing a SPL-BNL difference to a first predetermined threshold wherein an acute sound is indicated when the SPL-BNL difference is greater than the first predetermined threshold;

comparing the at least one peak level (SPL) to a second predetermined threshold wherein the acute sound is indicated when the SPL is greater than the second predetermined threshold;

estimating a proximity of the acute sound by performing a cross correlation analysis of signals captured by the at least two microphones;

identifying a peak in a cross correlation during the cross correlation analysis:

identifying a time lag in the acute sound between the at least two microphones to determine if the acute sound is user generated; and

passing the acute sound to an ear canal receiver if the acute sound was not user generated.

16. The system of claim 15 , wherein the one or more processors are further configured to prevent the reproduction of the acute sound via the ear canal receiver when no time lag is identified in the acute sound between the at least two microphones.

17. The system of claim 15 , wherein the earpiece is configured to measure the external ambient sound level of ambient sound outside of an ear canal when the ear canal is at least partially occluded by the earpiece.

18. The system of claim 15 , further comprising computer instructions which when executed by the one or more processors performs the operation of measuring an internal ambient sound level (iASL) due to residual ambient sound when the ear canal is at least partially occluded by the earpiece.

19. The system of claim 18 , wherein monitoring the change in the external ambient sound level (xASL) comprises monitoring frequency changes between the xASL and an internal ambient sound level (iASL).

20. The system of claim 19 , wherein the at least one processor is configured to produce sound levels within the ear canal at a same sound pressure level as the acute sound measured at an entrance of the ear canal.