Audio alert audibility estimation method and system

1. A method of estimating human perception of the audibility of an audio alert in the presence of a background noise, the method comprising:

in an alert audibility estimation system,

obtaining an input signal from a microphone,

obtaining, from an audio alert generation system for generating the audio alert, a real-time stream including a reference signal corresponding to the audio alert as the audio alert is being generated by the audio alert generation system,

obtaining from the input signal, using the reference signal, a background noise estimate and audio alert estimate represented at the microphone,

calculating an audibility metric representing human perception of audibility of the audio alert based on a comparison between the background noise estimate and the audio alert estimate, the comparison including a short-time cross correlation and a frequency-weighting that correlates with human perception of relative loudness; and

taking an action based on the audibility metric.

2. The method of claim 1 , wherein the comparison is based on a signal-to-noise ratio of the audio alert estimate to the background noise estimate.

3. The method of claim 1 , wherein obtaining the background noise estimate is based on adaptively filtering the audio alert from the input signal using the reference signal.

4. The method of claim 1 , wherein obtaining the background noise estimate is based on a comparison between an acoustic power of the input signal when the audio alert is active and an acoustic power of the input signal when the audio alert is inactive.

5. The method of claim 1 , wherein taking an action based on the audibility metric comprises playing the audio alert louder.

6. The method of claim 1 , wherein taking an action based on the audibility metric comprises modifying one or more properties of the audio alert and repeating playback.

7. The method of claim 1 , wherein taking an action based on the audibility metric comprises providing visual or haptic feedback to a human.

8. The method of claim 1 , wherein the audio alert generation system includes a speaker and wherein receiving the real-time stream as the audio alert is being generated by the audio alert generation system includes receiving the real-time stream as the audio alert is being output by the speaker.

9. The method of claim 1 , wherein the audio alert estimate is determined by suppressing noise in the audio alert input signal received from the microphone.

10. An alert audibility estimation system for estimating human perception of the audibility of an audio alert in the presence of a background noise, the system comprising:

a processor;

a microphone for generating an input signal corresponding to the audio alert and the background noise; and

a memory storing processor executable instructions that, when executed by the processor, cause the processor to:

receive an audio input signal from a microphone;

receive, from an audio alert generation system for generating the audio alert, a real-time stream including a reference signal corresponding to the audio alert as the audio alert is being generated by the audio alert generation system;

obtain from the audio input signal, using the reference signal, a background noise estimate and audio alert estimate represented at the microphone;

calculate an audibility metric representing human perception of the audibility of the audio alert based on a comparison between the background noise estimate and the audio alert estimate, the comparison including a short-time cross correlation and a frequency-weighting that correlates with human perception of relative loudness; and

cause an action to be taken based on the audibility metric.

11. The system of claim 10 , wherein the comparison is based on a signal-to-noise ratio of the audio alert estimate to the background noise estimate.

12. The system of claim 10 , wherein the process is further configured to obtain the background noise estimate based on adaptively filtering the audio alert from the input signal using the reference signal.

13. The system of claim 10 , wherein the processor is further configured to obtain the background noise estimate based on a comparison between an acoustic power of the input signal when the audio alert is active and an acoustic power of the input signal when the audio alert is inactive.

14. The system of claim 10 , wherein the action to be taken is to modify one or more properties of the audio alert and repeat playback.

15. The system of claim 10 , wherein the action to be taken is to provide visual or haptic feedback to a human.

16. A non-transitory computer-readable storage medium storing processor-executable instructions to estimate human perception of the audibility of an audio alert in the presence of a background noise, wherein the processor-executable instructions, when executed by a processor in an alert audibility estimation system, are to cause the processor to:

receive an audio input signal from a microphone;

obtain, from an audio alert generation system for generating the audio alert, a real-time stream including a reference signal corresponding to the audio alert as the audio alert is being generated by the audio alert generation system;

obtain from the audio input signal, using the reference signal, a background noise estimate and audio alert estimate represented at the microphone;

calculate an audibility metric representing human perception of the audibility of the audio alert based on a comparison between the background noise estimate and the audio alert estimate, the comparison including a short-time cross correlation and a frequency-weighting that correlates with human perception of relative loudness; and

cause an action to be taken based on the audibility metric.