Electro acoustic system built-in test and calibration method

• US 20060039568A1
• Filed: 01/06/2005
• Published: 02/23/2006
• Est. Priority Date: 08/20/2004
• Status: Active Grant

• Current Assignee: Fortemedia, Inc.
• Original Assignee: Fortemedia, Inc.
• Inventors: Bai, Bo-Ren, Lee, Yi-Bing
• Granted Patent: US 7,602,923 B2
• Time in Patent Office: Days
• US Class Current: 381/59
• CPC Class Codes: H04R 29/00 Monitoring arrangements; Testing arrangements for hearing aids H04R25/30; detection of loudspeaker connection H04R5/04; sound-field adaptation dependent on speaker detection H04S7/308

Abstract

An electro acoustic system built-in test and calibration method utilizes a built-in self-test module to send a test signal through a first circuit device to an audio transmitter, causing the audio transmitter to output a test signal, for enabling the test signal to be received by a audio receiver and then processed by a connected circuit device and converted into a feedback digital signal to the self-test module for comparing the linearity relative to the originally provided test signal so that the parameter values and conformity of circuit devices can be optimized subject to comparison result. The test and adjustment procedure is recycled for other parameter items, and a warning signal is produced when proper adjustment cannot be done. This built-in test and calibration module can be achieved in the form of an independent firmware code module, using the same DSP (digital signal processor) engine that drives the system for the self test purpose, in so doing, the function of self test can be called along the production line, in use, throughout the service life of the product, and virtually without any additional cost.

Claims

1. An electro acoustic system built-in test and calibration method comprising the steps of:

(a) driving a self-test module to send a test signal through a first circuit device to an audio device to produce a test audio signal;

(b) with at least one audio receiver to receive the test signal, for enabling the received test signal to be sent by the audio receiver to at least one second circuit device for converting into a feedback digital signal for comparing the linearity difference between the test signal and the feedback digital signal by the self-test module; and

(c) determining if to adjust the parameter values of the first circuit device and the second circuit device to the optimized status subject to the linearity difference comparison result.

2. The electro acoustic system built-in test and calibration method as claimed in claim 1, wherein the self-test module is built in as an integrated circuit or as an independent firmware module of the original digital signal processor that constitute the calculation engine of the product.

3. The electro acoustic system built-in test and calibration method as claimed in claim 1, wherein the parameter items of the first circuit device and the second circuit device include gain, sensitivity, phase delay, and frequency response.

4. The electro acoustic system built-in test and calibration method as claimed in claim 1, wherein the audio transmitter is a speaker, and each the audio receiver is a microphone.

5. The electro acoustic system built-in test and calibration method as claimed in claim 1, wherein the first circuit device and the second circuit device each comprise a Codec adapted to convert a digital signal into an analog signal and an analog signal into a digital signal.

6. The electro acoustic system built-in test and calibration method as claimed in claim 1, wherein when the linear difference between the test signal and the feedback digital signal surpassed a predetermined value, it is necessary to adjust the parameter values of the first circuit device and the second circuit device.

7. The electro acoustic system built-in test and calibration method as claimed in claim 1, further comprising a step (d) to adjust the parameter value of the first circuit device when the linear difference between the test signal and the feedback digital signal surpassed a predetermined value, the step (d) being achieved by:

setting up a predetermined median for the second circuit device and a predetermined maximum value for the first circuit device, and then driving the self-test module to send out a test signal and to use a control signal to gradually lower the maximum value until that the linear relationship between the test signal sent by the self-test module and the feedback digital signal reaches a predetermined range, for enabling the value at this status to be regarded as the optimized parameter value for the first circuit device, and then setting the maximum value of the second circuit device after determination of the parameter value of the first circuit device, and then driving the self-test module to send a test signal and to use a control signal to lower the set maximum value of the at least one second circuit device until that the linear relationship between the test signal sent by the self-test module and the feedback digital signal reaches a predetermined range, for enabling the value at this status to be regarded as the optimized parameter value for the second circuit device.

8. The electro acoustic system built-in test and calibration method as claimed in claim 7, wherein when an overload occurred in the loop between the first circuit device and the second circuit device, the setting of one of the first circuit device and the second circuit device causes the whole circuit to produce a nonlinear relationship.

9. The electro acoustic system built-in test and calibration method as claimed in claim 1, wherein the self-test module sends different test signals to automatically circulate the test when testing multiple parameter items.

10. The electro acoustic system built-in test and calibration method as claimed in claim 1, further comprising a sub-step of driving the self-test module to send out a warning signal when the self-test module is unable to optimize the parameter value of one of the first circuit device and the at least one second circuit device.

11. An electro acoustic system built-in test and calibration method comprising the steps of:

(a) driving a self-test module to send a test signal through a first circuit device to a audio transmitter to produce a test signal;

(b) with a plurality of audio receivers to receive the test signal, for enabling the received test signal to be sent by the respective audio receiver to a respective second circuit device for converting into a feedback digital signal for comparing the linear difference between the test signal and the feedback digital signal by the self-test module; and

(c) determining if to adjust the parameter value of the first circuit device relative to the parameter values of the second circuit devices being respectively connected to the audio receivers, comparing the conformity of the parameter values of the second circuit devices with the received feedback digital signal and then optimizing the conformity.

12. The electro acoustic system built-in test and calibration method as claimed in claim 11, wherein the self-test module is built in an integrated circuit or digital signal processor.

13. The electro acoustic system built-in test and calibration method as claimed in claim 11, wherein the parameter items of the first circuit device and the second circuit devices include gain difference, sensitivity difference, phase delay difference, and frequency response difference.

14. The electro acoustic system built-in test and calibration method as claimed in claim 11, wherein the audio transmitter is a speaker;

each the audio receiver is a microphone;

the first circuit device and the second circuit devices each comprise a Codec adapted to convert a digital signal into an analog signal and an analog signal into a digital signal.

15. The electro acoustic system built-in test and calibration method as claimed in claim 11, wherein when the linear difference between the test signal and the feedback digital signal surpassed a predetermined value, it is necessary to adjust the parameter values of the first circuit device and the second circuit devices.

16. The electro acoustic system built-in test and calibration method as claimed in claim 11, further comprising a step (d) to adjust the parameter value of the first circuit device when the linear difference between the test signal and the feedback digital signal surpassed a predetermined value, the step (d) being achieved by:

setting up a predetermined median for the second circuit device and a predetermined maximum value for the first circuit device, and then driving the self-test module to send out a test signal and to use a control signal to gradually lower the maximum value until that the linear relationship between the test signal sent by the self-test module and the feedback digital signal reaches a predetermined range, for enabling the value at this status to be regarded as the optimized parameter value for the first circuit device, and then setting the maximum value of the second circuit devices after determination of the parameter value of the first circuit device, and then driving the self-test module to send a test signal and to use a control signal to lower the set maximum value of the second circuit devices until that the linear relationship between the test signal sent by the self-test module and the feedback digital signal reaches a predetermined range, for enabling the value at this status to be regarded as the optimized parameter value for the second circuit devices.

17. The electro acoustic system built-in test and calibration method as claimed in claim 16, wherein when an overload occurred in the loop between the first circuit device and the second circuit devices, the setting of one of the first circuit device and the second circuit devices causes the whole circuit to produce a nonlinear relationship.

18. The electro acoustic system built-in test and calibration method as claimed in claim 16, wherein when the feedback digital signal between of the second circuit devices is not in conformity, the settings of the parameter values of the second circuit devices are not optimized and a further correction is necessary;

if the desired conformity is not achievable after repeated adjustment, it means a severe difference between the second circuit devices, and self-test module will output a warning signal.

19. The electro acoustic system built-in test and calibration method as claimed in claim 11, wherein the self-test module sends different test signals to automatically circulate the test when testing multiple parameter items.

20. The electro acoustic system built-in test and calibration method as claimed in claim 11, further comprising a sub-step of driving the self-test module to send out a warning signal when the self-test module is unable to optimize the parameter value of one of the first circuit device and the second circuit devices.