Systems and methods for self-administering a sound test

Patent metadata

Field	Value
Publication number	US-9953516-B2
Application number	US-201514717569-A
Country	US
Kind code	B2
Filing date	May 20, 2015
Priority date	May 20, 2015
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Systems and methods for self-administering a sound test to verify operation of a speaker and/or alarm within a hazard detection system are described herein. The sound test can verify that the audible sources such as the alarm and speaker operate at the requisite loudness and frequencies. In addition, the sound test can be self-administered in that it does not require the presence of a person to initiate or verify that the audible sources are functioning properly.

First claim

What is claimed is:

1. A method for self-administering a sound test in a hazard detection system comprising a housing that contains a microphone, a speaker, and a buzzer, the method comprising:
instructing the speaker and the buzzer to emit in succession a speaker audio signal followed by a buzzer audio signal, wherein the buzzer audio signal is emitted with a sound of at least 85 decibels and having a frequency centered around 3 kHz, and wherein the speaker is configured to emit human audio speech having a signal energy intensity at least one order of magnitude less than the buzzer audio signal in response to detection of a hazard;
evaluating energy monitored by the microphone during emission of the speaker audio signal and the buzzer audio signal to assess whether the speaker and the buzzer pass a self-administered sound test;
sounding the buzzer audio signal in response to a detection of a hazard; and
playing back a voice through the speaker in response to the detection of the hazard.

2. The method of claim 1 , wherein the speaker audio signal comprises two distinct tones.

3. The method of claim 2 , wherein a second emitted tone is an octave higher than a first emitted tone.

4. The method of claim 1 , wherein the buzzer audio signal comprises two buzzer sounds.

5. The method of claim 1 , wherein the speaker audio signal is characterized by an amplitude that is an order of magnitude less than an amplitude of the buzzer audio signal.

6. The method of claim 1 , wherein the speaker audio signal and the buzzer audio signal are known signals, the method further comprising:
correlating the monitored signal energy of each signal to an expected signal energy for that signal to determine whether the speaker and the buzzer pass the self-administered sound test.

7. The method of claim 1 , further comprising:
performing a speaker test to assess operation of the speaker; and
performing a buzzer test to assess operation of the buzzer.

8. The method of claim 7 , wherein performing the buzzer test comprises:
performing frequency domain analysis and time domain analysis on the energy monitored by microphone during emission of the buzzer audio signal; and
comparing results of the frequency domain analysis and time domain analysis to determine whether the buzzer passes the self-administered sound test.

9. The method of claim 1 , further comprising:
receiving a microphone signal from the microphone when it is monitoring the speaker audio signal, the speaker audio signal characterized as having multiple tones;
filtering the received microphone signal into a plurality of evaluation paths, each evaluation path associated with one of the tones;
performing envelope detection on the filtered microphone signal in each evaluation path; and
performing a minimum distance classification on the filtered microphone signal in each evaluation path to determine whether the tone associated with the path meets minimum distance determination criteria.

10. The method of claim 9 , wherein the filtering comprises filtering the microphone signal using digital filters within the microphone to provide a first filtered microphone signal.

11. The method of claim 10 , wherein filtering comprises using a band splitting filter to split the first filtered microphone into the plurality of evaluation paths.

12. The method of claim 10 , wherein the filtering comprises:
applying a low pass finite impulse response filter to the first filtered microphone signal to reject out-of-band signals; and
using a band splitting filter to split the first filtered microphone into the plurality of evaluation paths.

13. The method of claim 1 , wherein the filtering comprising:
a first filter bank that separates a first tone out of the microphone for use in a first one of the evaluation paths; and
at least a second filter bank that separates at least a second tone out of the microphone signal for use in at least a second one of the evaluation paths.

14. The method of claim 1 , further comprising:
receiving a microphone signal from the microphone when it is monitoring the buzzer audio signal, the buzzer audio signal characterized as having multiple blips occurring within the same frequency range;
estimating time domain energy of the received microphone signal;
estimating frequency domain energy of the received microphone signal; and
comparing the estimated time domain energy to the estimated frequency domain energy to determine if they are within a fixed percentage of each other.

15. The method of claim 14 , further comprising:
estimating frequency of the received microphone signal; and
determining whether the estimated frequency is within a fixed percentage of the frequency range of the buzzer audio signal.

16. The method of claim 14 , further comprising:
filtering the microphone signal using digital filters within the microphone to provide a second filtered microphone signal; and
applying a high pass finite impulse response filter to the second filtered microphone signal to reject out-of-band signals.

17. The method of claim 16 , wherein estimating the time domain energy comprises:
applying threshold detection to the second filtered microphone signal to acquire samples that exceed a threshold;
storing a plurality of second filtered microphone signal samples in a buffer in response to determining that the sample exceeds the threshold, wherein the estimated time domain energy is derived from the samples stored in the buffer.

18. The method claim 16 , wherein estimating the frequency domain energy comprises:
buffering a plurality of samples of the second filtered microphone signal; and
applying a digital Fourier transform to the buffered samples to provide frequency domain samples, wherein the wherein the estimated frequency domain energy is derived from the frequency domain samples.

19. The method of claim 18 , further comprising:
determining a maximum magnitude of the frequency domain samples;
estimating a frequency of the second filtered microphone signal based on the frequency domain sample having the determined maximum magnitude.

20. The method of claim 14 , wherein estimating the frequency domain energy comprises:
using a third filter bank to obtain frequency domain samples.

21. A hazard detection system, comprising:
a buzzer for emitting a buzzer audio signal of at least 85 decibels and having a frequency centered around 3 kHz;
a speaker separate from the buzzer, but contained within a common housing with the buzzer, and configured to emit human audio speech having a signal energy intensity at least one order of magnitude less than the buzzer audio signal in response to detection of a hazard, wherein the human audio speech is played back through the speaker in response to detection of a hazard;
a microphone separate from the buzzer and the speaker and contained in the common housing; and
processor coupled to the loud sounder, speaker, and microphone, wherein the processor is operative to:
instruct the speaker and the loud sounder to emit in succession a speaker audio signal followed by the buzzer audio signal; and
evaluate energy monitored by the microphone during emission of the speaker audio signal and the buzzer audio signal to assess whether the speaker and the buzzer pass a self-administered sound test.

22. The system of claim 21 , further comprising a visual indicator, wherein the processor is operative to cause the visual indictor to project a display based on the resul

Assignees

• Google Llc

Inventors

• Warren Daniel Adam
• Heyl Lawrence Frederick
• Satterthwaite Jr Edwin H
• Clark Steven
• Ho Dietrich
• Webb Nicholas Unger
• Moore Tyler

Classifications

• G08B5/36

  using visible light sources · CPC title

• G08B25/009

  Signalling of the alarm condition to a substation whose identity is signalled to a central station, e.g. relaying alarm signals in order to extend communication range · CPC title

• G08B29/126 Primary

  of annunciator circuits · CPC title