Patent Publication Number: US-8116466-B2

Title: Apparatus and method for testing sound input and output of sound card

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus and a method for testing a sound card. More particularly, the present invention relates to an apparatus and a method for testing a sound card, applicable for detecting whether a sound leakage problem occurs between sound channels of the sound card. 
     2. Related Art 
     The sound card is an indispensable periphery in a personal computer (PC). Besides offering the common functions of playing music and movies, the sound card is also applied in sound input, for example, sound recording, sound input for voice over IP (VoIP). 
     A conventional manner for testing the sound card is that, the sound card is installed on the PC, and individual sound channels are connected to corresponding speakers via different signal lines, or the signal lines are connected to microphone input ends of the corresponding sound channels, for example, a left channel output is connected to a left channel input. A sound card testing program on a control unit sends a testing audio signal to each sound channel one by one, and according to the sound sent by the testing program to each sound channel, the tester listens to the sound emitted from the corresponding speaker, so as to determine whether an error occurs or not. 
     As for the above testing manner, the signal lines must be installed manually one by one, and in addition, the testers must pay more attention to the testing audio signal generated by the testing program. Therefore, the following problems easily occur during the testing process. Firstly, if the testers do not note the testing sound generated by one of the speakers, they have to listen to the sound from each speaker once again. Secondly, if the signal lines of a single sound card is replaced frequently, the interface end of the sound card may be loosen, and the sound card easily generates unnecessary noises, so as to affect the testing result. Furthermore, the output interfaces in the current sound card are gradually increased (for example, 5.1-channel or 7.1-channel), such that the manual listening process is quite time-costing. 
     SUMMARY OF THE INVENTION 
     In view of the above problems, the object of present invention is provided with an apparatus for testing a sound card, capable of detecting whether a sound leakage problem occurs in a sounding interface of the sound card in the PC by using a mono/dual-channel sound-receiving unit. 
     In order to achieve the above object, the apparatus for testing the sound card provided by the present invention includes a switching circuit and a switching unit. 
     The switching circuit is electrically connected to a sounding interface and a sound-receiving interface of the sound card respectively, and has a plurality of transmitting paths. The switching circuit is used to receive a first sound channel and a second sound channel, and to connect the first sound channel and the second sound channel to corresponding transmitting paths, so as to transmit the audio signal back to the sound-receiving interface. The PC monitors a first testing audio signal transmitted via the first sound channel and/or a second testing audio signal transmitted via the second sound channel, and examines whether the first sound channel has the second testing audio signal or whether the second sound channel has the first testing audio signal, so as to determine whether the sound leakage problem occurs between the first sound channel and the second sound channel. The switching unit is electrically connected to the sounding interface and the switching circuit respectively, for receiving the first sound channel and the second sound channel. The switching unit alters the transmitting paths in the switching circuit according to a first switching audio signal and/or a second switching audio signal. 
     From another aspect of the present invention, the present invention provides a method for testing a sound card, applicable for detecting whether the sound leakage problem occurs in the sounding interface of the sound card in the PC. The sounding interface includes a first sound channel and a second sound channel respectively, and the testing method includes the following steps. Firstly, a switching unit and a switching circuit are provided, in which the switching unit is electrically connected to the sounding interface and the switching circuit respectively, and the switching circuit is electrically connected to the sounding interface and a sound-receiving interface in the sound card respectively. Next, the PC sends a first switching audio signal to the first sound channel or the second sound channel. Then, the switching unit alters the transmitting paths in the switching circuit according to the first switching audio signal, and connects the first sound channel and the second sound channel to the corresponding transmitting paths, so as to transmit the audio signal back to the sound-receiving interface. Then, the PC monitors whether the first sound channel has the testing audio signal transmitted via the second sound channel and monitors whether the second sound channel has the testing audio signal transmitted via the first sound channel. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given herein below for illustration only, which thus is not limitative of the present invention, and wherein: 
         FIG. 1  is a schematic view of a preferred embodiment of the present invention; 
         FIG. 2  is a flow chart of the operation of the present invention; 
         FIG. 3   a  is a demonstrative schematic view of the flow when the present invention is applied to a dual-channel sound-receiving unit according to an embodiment of the present invention; 
         FIG. 3   b  is a demonstrative schematic view of the flow when the present invention is applied to the dual-channel sound-receiving unit according to an embodiment of the present invention; 
         FIG. 4   a  is a demonstrative schematic view of the flow when the present invention is applied to a mono-channel sound-receiving unit according to an embodiment of the present invention; and 
         FIG. 4   b  is a demonstrative schematic view of the flow when the present invention is applied to the mono-channel sound-receiving unit according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The apparatus for testing the sound card provided by the present invention is used to detect whether the sound leakage problem occurs in the sounding interface and the sound-receiving interface of the sound card in the PC. A testing apparatus  130  includes a switching unit  131  and a switching circuit  133 . 
     Referring to  FIG. 1 , it is a schematic view of a preferred embodiment of the present invention. The switching unit  131  is electrically connected to a sounding interface  121  and a switching circuit  133  respectively. Firstly, a sound card  120  is installed on a PC  110 , and the sound card  120  in this embodiment is not limited to a certain interface, but can be any one of an ISA interface, a PCI interface, or a USB interface. Herein, a dual-channel sound card  120  is taken as an example for demonstration in this embodiment. The sound card  120  further includes the sounding interface  121  and the sound-receiving interface  122 , and the sounding interface  121  is used to transmit audio signals. In this embodiment, the dual-channel sound card  120  is taken as an example, so the sounding interface  121  respectively provides a first sound channel (not shown) and a second sound channel (not shown). The first sound channel is used to transfer a first switching audio signal, a second switching audio signal, and a first testing audio signal, the second sound channel is used to transfer the first switching audio signal, the second switching audio signal, and the second testing audio signal. The audio signals can be music segments or specific waveforms, for example, sine waves or successive square waves. 
     The switching unit  131  is used to receive the first sound channel and the second sound channel, and to alter the transmitting paths in the switching circuit  133  according to the first switching audio signal and/or the second switching audio signal. The switching unit  131  further includes a wave-shaping unit  1311  and a decoding unit  1312 . The wave-shaping unit  1311  is electrically connected to the sounding interface  121  and the decoding unit  1312 . The wave-shaping unit  1311  can be, but not limited to, a 555 timer. The wave-shaping unit  1311  is used to receive the first audio signal and the second audio signal, and to convert the received audio signals into corresponding switching signals. 
     The decoding unit  1312  controls the path constitution of the connecting circuit according to the switching signals. The decoding unit  1312  can be, but not limited to, a multi-path select circuit formed by a PT2272 decoder. The 555 timer converts a specific audio file (a sine wave or a music segment) sent from the sound card  120  into a corresponding waveform and outputs the waveform to the PT2272 decoder. Then, the PT2272 decoder selects a corresponding transmitting path according to the waveform. 
     The switching circuit  133  is electrically connected to the sounding interface  121  and the sound-receiving interface of the sound card  120  respectively, and has a plurality of transmitting paths. The switching circuit  133  is used to receive the first sound channel and the second sound channel, and to connect the first sound channel and the second sound channel to the corresponding transmitting paths, so as to transmit the audio signal back to the sound-receiving interface. The sound-receiving interface is a mono-channel sound input interface or a dual-channel sound input interface. Generally, besides the microphone input, the sound-receiving interface also refers to line-in. Based upon a frequency domain comparison method, the PC  110  can determine whether the audio signal received by the sound-receiving interface is consistent with the audio signal sent via the sound channel, thereby determining whether the noise interference problem occurs in each sound channel during transmission. The frequency domain comparison method can be, but not limited to, Fourier convert, wavelet convert, or designs of discrete cosine convert. Once receiving the switching signal, the decoding unit  1312  switches the first sound channel and the second sound channel to the corresponding transmitting path, such that the testing audio signal can be transmitted back to the PC  110 . The PC  110  monitors the first testing audio signal transmitted via the first sound channel and/or the second testing audio signal transmitted via the second sound channel. The PC  110  examines whether the first sound channel has the second testing audio signal or whether the second sound channel has the first testing audio signal, so as to determine whether the sound leakage problem occurs between the first sound channel and the second sound channel. 
     Referring to  FIG. 2 , it is a flow chart of the operation of the present invention. The testing method includes the following steps. A switching unit and a switching circuit are provided, in which the switching unit is electrically connected to the sounding interface and the switching circuit respectively, and the switching circuit is electrically connected to the sounding interface and the sound-receiving interface in the sound card respectively (Step S 210 ). Next, the PC sends the first switching audio signal to the first sound channel or the second sound channel (Step S 220 ). Then, the switching unit alters the transmitting paths in the switching circuit  133  according to the first switching audio signal, and connects the first sound channel and the second sound channel to the corresponding transmitting paths, so as to transmit the audio signal back to the sound-receiving interface (Step S 230 ). Then, the PC monitors whether the first sound channel has the testing audio signal transmitted via the second sound channel and whether the second sound channel has the testing audio signal transmitted via the first sound channel (Step S 240 ), thereby examining whether the sound leakage problem occurs between the first sound channel and the second sound channel. In order to clearly demonstrate the operation steps for detecting the sound leakage in the present invention, refer to  FIGS. 3   a  and  3   b , they are respectively demonstrative schematic views of the flow when the present invention is applied to a dual-channel sound-receiving unit according to an embodiment of the present invention. Herein, the dual-channel sound-receiving interface  122  is used as the sound input for the PC  110 . The connection of each element in this embodiment is mostly similar to that mentioned in the above description, which thus is not described herein any more. 
     It should be particularly noted that, the connecting circuit in  FIG. 3   a  is electrically connected to the first sound channel, the second sound channel, and the sound-receiving interface  122  respectively. In  FIG. 3   a , the first sound channel is respectively connected to two corresponding transmitting paths. The first transmitting path is connected to the sound-receiving interface  122  (that is, a node  1331  is connected to a node  1333 , so as to be connected to the left channel sound-receiving interface  1222 ), and the second transmitting path is idle (that is, the node  1331  is connected to a node  1334 ). The second sound channel has one transmitting path, a third transmitting path is electrically connected to the sound-receiving interface  122  (that is, a node  1332  is connected to a node  1335 , so as to be connected to the right channel sound-receiving interface  1221 ). 
     In this embodiment, the manner for the switching unit  131  to alter the transmitting paths in the switching circuit  133  is to take the first transmitting path and the third transmitting path as a group of transmitting paths. Once receiving the first switching audio signal, the switching unit  131  alters the transmitting paths into a configuration shown in  FIG. 3   a . Once receiving the second switching audio signal, the switching unit  131  alters the transmitting paths into a configuration shown in  FIG. 3   b . Firstly, the first sound channel is tested, and it is assumed that the first testing audio signal is a sine wave of 20 Hz. The PC  110  sends the first testing audio signal via the first sound channel, and the first sound channel is connected to the left channel sound-receiving interface  1222 , so the left channel sound-receiving interface  1222  can only receive the first testing audio signal. If the PC  110  analyzes that other sounds are also existed through the frequency domain analyzing method, it represents that the sound leakage problem occurs between the first sound channel and the left channel sound-receiving interface. Furthermore, the PC  110  can add the second testing audio signal of 2000 Hz into the second sound channel. When the PC  110  analyzes the left channel sound-receiving interface  1222 , if it is in the normal condition, only a sine wave of 20 Hz exists. If it is detected that a sine wave of 2000 Hz also exists, it represents that the sound leakage problem exists between the first sound channel and the second sound channel. 
     The second sound channel can also be tested through the above manner, that is, it is assumed that the first testing audio signal is a sine wave of 20 Hz. The PC  110  sends the first testing audio signal through the second sound channel, and the second sound channel is connected to the right channel sound-receiving interface  1221 , so the right channel sound-receiving interface  1221  can only receive the first testing audio signal. If the PC  110  analyzes that other sounds are also existed through the frequency domain analyzing method, it represents that the sound leakage problem occurs between the second sound channel and the right channel sound-receiving interface. Furthermore, the PC  110  can add the second testing audio signal of 2000 Hz into the first sound channel. When the PC  110  analyzes the right channel sound-receiving interface  1221 , if it is in the normal condition, only a sine wave of 20 Hz exists. If it is detected that a sine wave of 2000 Hz also exists, it represents that the sound leakage problem occurs between the second sound channel and the first sound channel. If it intends to test the second sound channel more accurately, the connecting manner of the transmitting paths can be obtained with reference to  FIG. 3   b . Firstly, the PC  110  sends the first switching audio signal and the second switching audio signal to respectively switch and connect the node  1331  to the node  1334 , and to connect the node  1332  to the node  1335 . At this time, the first sound channel is idle, which does not output any testing audio signal to the sound-receiving interface  122 , and the second sound channel is connected to the right channel sound-receiving interface  1221 . 
     Similarly, it is assumed that the first testing audio signal is a sine wave of 20 Hz. The PC  110  sends the second testing audio signal via the second sound channel, and the second sound channel is connected to the right channel sound-receiving interface  1221 , so the right channel sound-receiving interface  1221  can only receive the second testing audio signal. If the PC  110  analyzes that other sounds are also existed through the frequency domain analyzing method, it represents that the sound leakage problem occurs between the second sound channel and the right channel sound-receiving interface  1221 . The PC  110  can add the first testing audio signal of 2000 Hz into the first sound channel. When the PC  110  analyzes the right channel sound-receiving interface  1221 , if it is detected that a sine wave of 2000 Hz exists, it represents that the sound leakage problem occurs between the first sound channel and the second sound channel, for example, under a situation that the first sound channel and the second sound channel are serially connected with each other. 
     Definitely, the PC  110  is not limited to using a specific sound frequency as the reference for detecting the sound leakage problem, and the PC  110  can also send different music segments via different sound channels. For example, the first music is played via the first sound channel, and the second music is played via the second sound channel. If the second music is detected in the first sound channel, the sound leakage problem occurs in the second sound channel. 
     Referring to  FIGS. 4   a  and  4   b , they are respectively demonstrative schematic views of the flow when the present invention is applied to a mono-channel sound-receiving unit according to an embodiment of the present invention. The difference between  FIGS. 4   a  and  3   a  lies in the number of the corresponding sound channels for the sound-receiving interface  122  used for receiving. The sound-receiving interface  122  in  FIG. 4   a  is a mono-channel sound-receiving interface  1223 . Difference from the dual-channel sound-receiving interface, when the mono-channel sound-receiving interface  1223  and the testing apparatus  130  are connected, the practical depth of the mono-channel sound-receiving interface  1223  is shorter than that of the dual-channel sound-receiving interface, so an idle state is formed from the node  1335  to the mono-channel sound-receiving interface  1223 , as shown in  FIG. 4   a.    
     When the first sound channel is tested, it is also assumed herein that the first testing audio signal is a sine wave of 20 Hz. The PC  110  sends the first testing audio signal via the first sound channel, and the first sound channel is connected to the mono-channel sound-receiving interface  1223 , so the mono-channel sound-receiving interface  1223  can only receive the first testing audio signal. If the PC  110  analyzes that other sounds are also existed through the frequency domain analyzing method, it represents that the sound leakage problem occurs between the first sound channel and the mono-channel sound-receiving interface  1223 . Next, the PC  110  can add the second testing audio signal of 2000 Hz into the second sound channel. When the PC  110  analyzes the mono-channel sound-receiving interface  1223 , if it is in the normal condition, only the sine wave of 20 Hz exists. If it is detected that the sine wave of 2000 Hz also exists, it represents that the sound leakage problem occurs between the first sound channel and the second sound channel. 
     If it intends to test the second sound channel, the connecting manner of the transmitting paths can be obtained with reference to  FIG. 4   b . Firstly, the PC  110  sends the first switching audio signal and the second switching audio signal to respectively switch and connect the node  1331  to the node  1334 , and to connect the node  1332  to the node  1336 . At this time, the first sound channel is idle, which does not output any testing audio signal to the sound-receiving interface  122 , and the second sound channel is connected to the mono-channel sound-receiving interface  1223 . 
     Similarly, it is assumed that the second testing audio signal is a sine wave of 20 Hz. The PC  110  sends the second testing audio signal via the second sound channel, and the second sound channel is connected to the mono-channel sound-receiving interface  1223 , so the mono-channel sound-receiving interface  1223  can only receive the second testing audio signal. If the PC  110  analyzes that other sounds are also existed through the frequency domain analyzing method, it represents that the sound leakage problem occurs between the second sound channel and the mono-channel sound-receiving interface. The PC  110  can add the first testing audio signal of 2000 Hz into the first sound channel. When the PC  110  analyzes the mono-channel sound-receiving interface  1223 , if it is detected that a sine wave of 2000 Hz exists, it represents that the sound leakage problem occurs between the first sound channel and the second sound channel. The present invention provides a testing apparatus  130  and a testing method for detecting the sound card  120 , which are applicable for detecting whether the sound leakage problem occurs in the sounding interface  121  of the sound card  120  in the PC  110 . The switching unit  131  in the testing apparatus  130  not only can switch the received switching audio signals to the corresponding connecting circuit, but also the switching unit  131  is not limited to the fact that the sound-receiving interface is a mono-channel or a dual-channel. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.