Patent Grant
9215540
The present invention relates to a buzz detecting method and a buzz detecting system, and more particularly to a buzz detecting method and a buzz detecting system for using an instrument to read and analyze an under-test sound signal from an under-test sound playing device and judge whether the under-test sound playing device generates a buzz while playing sound.
Nowadays, audio and video products are gradually used in homes. Consequently, the market demands on sound playing devices (e.g. single speakers or stereo devices) are growing. For maintaining the quality of the sound playing devices, after the sound playing devices are produced at the production side, it is necessary to test the sound playing devices. After the testing procedure is done, the manufacturer may assure that no buzz is generated while the sound playing devices play sound.
In accordance with a conventional testing method, after the signals with different frequencies are continuously transmitted to the sound playing device, the tester judges whether the sound outputted from the sound playing device contains a buzz by manually hearing the signals with ears. Consequently, the quality of the sound playing device may be discriminated.
However, the testing procedure has to be implemented by the trained testers. Since the experiences and the body conditions of different testers are distinguished, the judgment about the testing result is very subjective and lacks of consistence. Moreover, after the hearing system of the tester has been intensively stimulated for a long time, the hearing system is possibly hurt.
For overcoming the above drawbacks and increasing the testing efficiency, there is a need of providing an automatic testing method and an automatic testing system to use an instrument to perform the testing procedure in replace of the human hearing system.
An object of the present invention provides an automatic buzz detecting method and an automatic buzz detecting system for a sound playing device in order to increase the testing efficiency.
In accordance with an aspect of the present invention, there is provided a buzz detecting method for testing whether an under-test sound playing device generates a buzz while playing sound. The buzz detecting method includes the following steps. Firstly, an audio processing device outputs plural baseband signals to the under-test sound playing device, so that plural under-test sound signals corresponding to the plural baseband signals are outputted from the under-test sound playing device. The plural baseband signals have different frequencies, and frequencies of the plural under-test sound signals are identical to corresponding frequencies of respective baseband signals. Then, a sound receiving device receives the plural under-test sound signals and transmits the plural under-test sound signals to the audio processing device. Then, an application program module converts the plural under-test sound signals into plural under-test frequency-domain signals corresponding to the plural under-test sound signals through Fourier transform. Then, the application program module calculates plural under-test noise ratios corresponding to the frequencies of respective under-test sound signals according to respective under-test frequency-domain signals. After the plural under-test noise ratios are compared with plural standard noise ratios of a standard sound playing device, the tester may judge whether the under-test sound playing device generates the buzz while playing sound. The standard sound playing device generates plural standard sound signals with plural frequencies corresponding to respective standard noise ratios. If the under-test noise ratio corresponding to any frequency of the plural under-test sound signals is higher than the standard noise ratio corresponding to the frequency by a specified ratio, it is determined that the under-test sound playing device generates the buzz while playing sound.
In accordance with another aspect of the present invention, there is provided a buzz detecting system for testing whether an under-test sound playing device generates a buzz while playing sound. The buzz detecting system includes an audio processing device, a processing unit, the under-test sound playing device, and a sound receiving device. The audio processing device outputs plural baseband signals, wherein the plural baseband signals have different frequencies. The processing unit is connected with the audio processing device, and includes an application program module and a storage unit. Moreover, plural standard noise ratios of a standard sound playing device are previously stored in the storage unit, wherein the standard sound playing device generates plural standard sound signals with plural frequencies corresponding to respective standard noise ratios. The under-test sound playing device is connected with the audio processing device, and receiving the plural baseband signals, so that plural under-test sound signals corresponding to the plural baseband signals are outputted from the under-test sound playing device. Moreover, the frequencies of the plural under-test sound signals are identical to corresponding frequencies of the respective baseband signals. The sound receiving device is connected with the audio processing device, and receives the plural under-test sound signals and transmits the plural under-test sound signals to the audio processing device. After the plural under-test sound signals are received by the audio processing device, the application program module converts the plural under-test sound signals into plural under-test frequency-domain signals corresponding to the plural under-test sound signals through Fourier transform, and the application program module calculates plural under-test noise ratios corresponding to the frequencies of respective under-test sound signals according to respective under-test frequency-domain signals. If the under-test noise ratio corresponding to any frequency of the plural under-test sound signals is higher than the standard noise ratio corresponding to the frequency by a specified ratio, it is determined that the under-test sound playing device generates the buzz while playing sound.
The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:
The present invention provides a buzz detecting method and a buzz detecting system for a sound playing device. In comparison with the conventional technology, the testing procedure is not necessarily implemented by the trained testers. In other words, the buzz detecting method and the buzz detecting system for the sound playing device according to the present invention may be automatically performed in order to detect the quality of the sound playing device.
The audio processing device 10 is a sound card or a dynamic signal acquisition (DSA) card. The processing unit 11 is connected with the audio processing device 10. In this embodiment, the processing unit 11 comprises an application program module 111 and a storage unit 112. Moreover, the audio processing device 10 and the processing unit 11 are connected with the same electronic device (not shown). An example of the electronic device includes but is not limited to a desktop computer or a notebook computer.
The under-test sound playing device 12 is a single speaker or a stereo device that undergoes a quality testing procedure. The under-test sound playing device 12 is connected with the audio processing device 10. An example of the sound receiving device 13 is a microphone. Moreover, the sound receiving device 13 is also connected with the audio processing device 10. An example of the display device 14 includes but is not limited to a computer monitor. Moreover, the display device 14 is connected with the processing unit 11.
The method of testing the under-test sound playing device 12 according to the preset invention comprises the following steps.
In a step A, the audio processing device 10 outputs plural baseband signals to the under-test sound playing device 12, so that plural under-test sound signals corresponding to the plural baseband signals are outputted from the under-test sound playing device 12.
In a step B, the sound receiving device 13 receives the plural under-test sound signals and transmits the plural under-test sound signals to the audio processing device 10.
In a step C, the application program module 111 converts the plural under-test sound signals into plural under-test frequency-domain signals corresponding to the plural under-test sound signals through Fourier transform.
In a step D, the application program module 111 calculates plural under-test noise ratios corresponding to the frequencies of respective under-test sound signals according to respective under-test frequency-domain signals.
In a step E, the plural under-test noise ratios are compared with plural standard noise ratios, thereby judging whether the under-test sound playing device 12 generates a buzz while playing sound.
Before the testing procedure is performed, the tester is unable to realize whether the under-test sound playing device 12 generates the buzz while playing sound, and the tester is unable to realize the occurrence frequency of the buzz. In the step A, plural under-test sound signals with plural frequencies are outputted to the under-test sound playing device 12. Consequently, the generation of buzzes in a wide frequency range can be detected.
Moreover, after each baseband signal is received by the under-test sound playing device 12, the corresponding sound signal (also referred as the under-test sound signal) is generated, the sound signal is converted into the corresponding frequency-domain signal, the under-test noise ratio corresponding to the frequency of the frequency-domain signal is calculated, and the noise ratio (also referred as the under-test noise ratio) of the under-test sound playing device 12 is compared with the corresponding standard noise ratio of the standard sound playing device. Consequently, the tester may judge whether the under-test sound playing device generates the buzz while playing sound and realize the occurrence frequency of the buzz. The operations of the buzz detecting method will be illustrated as follows.
Firstly, in the steps A, the audio processing device 10 continuously outputs the plural baseband signals to the under-test sound playing device 12, so that the plural under-test sound signals corresponding to the plural baseband signals are outputted from the under-test sound playing device 12. In this embodiment, the plural baseband signals are constituted by plural signals with different frequencies. The frequencies of each baseband signal are in the range between 50 Hz and 10000 Hz, but are not limited thereto. It is noted that the number of the baseband signals and the frequencies of the baseband signals are not restricted. Moreover, the difference between the frequencies of two consecutive baseband signals is not restricted. That is, the difference between the frequencies of two consecutive baseband signals may be determined according to the specifications of the sound playing device.
After the plural baseband signals are received by the under-test sound playing device 12, the plural under-test sound signals corresponding to the plural baseband signals are outputted from the under-test sound playing device 12. For example, if the plural baseband signals contain the signals with frequencies 100 Hz, 160 Hz, 315 Hz and 500 Hz, the under-test sound signals outputted from the under-test sound playing device 12 contain the signals with frequencies 100 Hz, 160 Hz, 315 Hz and 500 Hz.
At the same time, the sound receiving device 13 beside the under-test sound playing device 12 receives the plural under-test sound signals and transmits the plural under-test sound signals to the audio processing device 10. That is, the step B is performed. In this embodiment, after the sound receiving device 13 receives the plural under-test sound signals, the sound receiving device 13 generates plural digital signals and transmits the plural digital signals to the audio processing device 10. Then, according to the plural digital signals, the processing unit 11 generates plural under-test frequency-domain signals corresponding to the plural under-test sound signals. That is, the step C is performed.
For brevity, the formation of the under-test frequency-domain signals corresponding to the under-test sound signals will be illustrated by referring to the under-test sound signals corresponding to two baseband signals with the frequencies 315 Hz and 500 Hz. Please refer to
Firstly, a digital signal is generated according to the under-test sound signal corresponding to the baseband signal with the frequency 315 Hz, and the digital signal is received by the audio processing device 10. Consequently, the audio processing device 10 generates a time-domain waveform 21 with the frequency 315 Hz and transmits the time-domain waveform 21 to the application program module 111 of the processing unit 11. As shown in
Similarly, another digital signal is generated according to the under-test sound signal corresponding to the baseband signal with the frequency 500 Hz, and the digital signal is received by the audio processing device 10. Consequently, the audio processing device 10 generates a time-domain waveform 15 with the frequency 500 Hz and transmits the time-domain waveform 15 to the application program module 111 of the processing unit 11. As shown in
After the plural under-test frequency-domain signals are acquired, the application program module 111 implements the step D. That is, plural under-test noise ratios corresponding to the frequencies of respective under-test sound signals are calculated according to respective under-test frequency-domain signals.
As shown in
In the under-test frequency-domain signal 22 as shown in
However, it is unable to confirm whether a buzz interfering with the hearing sense is generated when the under-test sound signal with the frequency 315 Hz is played by the under-test sound playing device 12 according to
In
where, P and Q are both positive integers, and P is larger than 1 and smaller than Q.
In the above formula, H1 indicates the sound intensity level of the under-test frequency-domain signal 22 corresponding to a fundamental frequency of the under-test sound signal (i.e. the sound intensity level corresponding to the frequency 315 Hz); H2 indicates the sound intensity level of the under-test frequency-domain signal 22 corresponding to two multiples of the fundamental frequency of the under-test sound signal (i.e. the sound intensity level corresponding to the frequency 630 Hz); and the rest may be deduced by analogy. In an embodiment, P is 8, and Q is 50. It is noted that the values of P and Q may be varied according to the characteristics of the sound playing devices.
Similarly, in
After the above procedures are repeatedly done, the plural under-test noise ratios corresponding to the frequencies of respective under-test sound signals are calculated according to respective under-test frequency-domain signals. That is, the step D is completed.
When the comparison plot 19 is shown on the display device 14, the tester may finely tune the comparison plot 19 through the operation interface 23 of
Moreover, after a setting adjustment item 28 is clicked, the tester may designate a specified ratio. According to the specified ratio, an upper limit curve 20 is defined. The upper limit curve 20 indicates the maximum allowable under-test noise ratios of the first frequency-noise ratio curve 17 at plural frequencies that exceed the standard noise ratios of the second frequency-noise ratio curve 18 at the corresponding frequencies. For example, the specified ratio designated by the tester is 15%. In case that the standard noise ratio of the second frequency-noise ratio curve 18 at a frequency is 0.35, the noise ratio of the upper limit curve 20 at this frequency is 0.4025. That is, the maximum allowable under-test noise ratio of the first frequency-noise ratio curve 17 at this frequency is 0.4025.
If the under-test noise ratio of the first frequency-noise ratio curve 17 at a frequency does not exceed the upper limit curve 20, the tester may judge that the sound signal with this frequency is not suffered from serious distortion and no buzz interfering with the hearing sense is generated while the sound signal is played by the under-test sound playing device 12. Consequently, after the plural under-test noise ratios are compared with the upper limit curve 20 defined by the plural standard noise ratios, the tester may judge whether the under-test sound playing device 12 generates the buzz while playing sound and realize the occurrence frequency of the buzz. That is, the step E is performed. Since the first frequency-noise ratio curve 17 about the plural under-test noise ratios, the second frequency-noise ratio curve 18 about the plural standard noise ratios and the upper limit curve 20 are included in the same plot, the tester may directly examine the comparison plot 19 to analyze whether the under-test noise ratio of the first frequency-noise ratio curve 17 at any frequency exceeds the upper limit curve 20, thereby judging whether the buzz interfering with the hearing sense is generated by the under-test sound playing device 12. It is noted that the step E may be performed by the application program module 111 after the test item 29 is clicked. The testing result may be shown in a testing result display zone 30. Moreover, when the step E is implemented by the application program module 111, the comparison plot 19 may be not shown. The contents of the operation interface 23 of
As shown in
Hereinafter, a procedure of acquiring plural standard noise ratios will be illustrated with reference to
In a step A1, the audio processing device 10 outputs plural baseband signals to the standard sound playing device, so that plural standard sound signals corresponding to the plural baseband signals are outputted from the standard sound playing device.
In a step A2, the sound receiving device 13 receives the plural standard sound signals and transmits the plural standard sound signals to the audio processing device 10.
In a step A3, the application program module 111 converts the plural standard sound signals into plural standard frequency-domain signals corresponding to the plural standard sound signals through Fourier transform.
In a step A4, the application program module 111 calculates plural standard noise ratios corresponding to the frequencies of respective standard sound signals according to respective standard frequency-domain signals.
Except that the under-test sound playing device 12 is replaced by the standard sound playing device, the steps A1-A4 are substantially identical to the steps A-D, and are not redundantly described herein.
From the above descriptions, the present invention provides a buzz detecting method and a buzz detecting system. By the application program module 111, plural under-test sound signals are converted into plural under-test frequency-domain signals through Fourier transform. Moreover, the application program module 111 calculates plural under-test noise ratios corresponding to the frequencies of respective under-test sound signals according to respective under-test frequency-domain signals. After the plural under-test noise ratios are compared with plural standard noise ratios from the standard sound playing device, the application program module 111 may judge whether the under-test sound playing device 12 generates a buzz while playing sound. According to the buzz detecting method and the buzz detecting system of the present invention, the under-test sound signals are directly analyzed by the application program module 111. Since the testing procedure does not need to be implemented by the trained testers, the overall efficiency is largely enhanced.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014 1 0041842 | Jan 2014 | CN | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 20120106750 | Thormundsson | May 2012 | A1 |
| 20130129097 | Park | May 2013 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20150215717 A1 | Jul 2015 | US |
