The present disclosure relates to speech recognition and, more particularly, to methods and devices for training voice recognition databases.
Although speech recognition has been around for decades, the quality of speech recognition software and hardware has only recently reached a high enough level to appeal to a large number of consumers. One area in which speech recognition has become very popular in recent years is the smartphone and tablet computer industry. Using a speech recognition-enabled device, a consumer can perform such tasks as making phone calls, writing emails, and navigating with GPS using only voice commands.
Speech recognition in such devices is far from perfect, however. A speech recognition engine typically relies on a phoneme or command database to be able to recognize voice utterances. A user may, however, need to “train” the phoneme or command database to recognize his or her speech characteristics—accent, frequently mispronounced words and syllables, tonal characteristics, cadence, etc. Even after training, however, the phoneme or command database may not be accurate in all audio environments. For example, the presence of background noise can decrease speech recognition accuracy.
While the appended claims set forth the features of the present techniques with particularity, these techniques may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:
The present disclosure sets forth methods and an apparatus for training noise-based voice recognition model databases. The term “noise-based voice recognition model database” (abbreviated as “VR model database”) as used herein refers to a database that functions as a noise-based phoneme database, as a command database, or as both.
Various embodiments of the disclosure include manual and automated methods of training VR model databases. The manual embodiments of this disclosure include a directed training methodology in which the electronic device (also referred to as “device”) directs the user to perform operations, in response to which the device updates the VR model database. The device may carry out a manual training method during the initial setup of the device, or at any time when the procedure is launched by the user. For example, when the user is in a new type of noise environment, the user may launch the manual method to train the VR model database for that type of noise, and the device may store the new noise in a noise database.
The automated embodiments include methods launched by the device without the user's knowledge. The device may launch an automated method based on environmental characteristics, such as when it senses a new type of noise or in response to the user's actions. Examples of user actions that could launch an automated training method include the user launching a speech recognition session via a button press, gesture trigger, or voice trigger. In these cases, the device would use the user's speech as well as other noises it detects to further train the VR model database. The device could also use the user's speech and detected noise for the speech recognition process itself. In such a case, if the device reacts positively to the speech recognition result (i.e., carries out the action initiated by the speech recognition process as opposed to cancelling the action), the device would launch the automated training process using both the user's utterance from the speech recognition event and the result of that event as the training target.
According to various embodiments, the device trains the VR model database using previously-recorded noises and previously-recorded utterances (retrieved from a noise database and an utterance database, respectively) in addition to live utterances and live noises. Like the live noises and utterances, the previously-recorded utterances can be obtained in different noise environments and during different use cases of the device. The previously-recorded utterances and noises may be stored in, and retrieved from, a noise database and an utterance database, respectively. Additionally, the device can store the live utterances and the live noises in a noise database and an utterance database, respectively, for future use.
According to an embodiment, the device can train the VR model database in various ways, any of which, depending on the circumstances, may be used for both the manual and the automated training methodologies. For example, three methodologies relate to how the composite speech and noise signal is captured for the purpose of training the VR model databases. The first of these methods is based on a composite signal of speech and natural noise captured by the device. The second is based on capturing a composite signal of live speech with noise generated by the device's acoustic output transducer. The third is based on a composite signal that the device generates by mixing speech and noise that it captures live or that it retrieves from memory. This last embodiment can use speech captured in a quiet environment mixed with previously stored noise files, or captured noise mixed with previously stored speech utterances.
In one embodiment, an electronic device digitally combines a single voice input with each of a series of noise samples. Each noise sample is taken from a different audio environment (e.g., street noise, babble, interior car noise). The voice input/noise sample combinations are used to train the VR model database without the user having to repeat the voice input in each of the different environments. In one variation, the electronic device transmits the user's voice input to a server that maintains and trains the VR model database.
According to an embodiment, the method is carried out by recording an utterance, digitally combining the recorded utterance with a previously-recorded noise sample, and training a noise-based VR model database based on this digital combination. Using the same, single utterance, these steps may be repeated for each previously-recorded noise sample of a set of noise samples (e.g., noise samples of a noise database), and may be thus repeated prior to recording a different utterance. Over time, this process can be repeated so as to continually improve speech recognition.
Alternatively, the electronic device can generate an artificial noise environment using a predefined noise playback (pink, car, babble), or no feedback (silence) using the speakers on the device. The user speaks during the playback and without the playback. This allows the device to identify changes in user's speech characteristics in quiet vs. noisy audio environments. The VR model database can be trained based on this information.
One embodiment involves receiving an utterance via a microphone of an electronic device and, while receiving the utterance, reproducing a previously-recorded noise sample through a speaker of the electronic device. The microphone picks up both the utterance and the previously-recorded noise.
Yet another embodiment involves recording an utterance during a speech to text command (“STT”) mode, and determining whether the recorded utterance is an STT command. Such a determination may be made based on whether a word-recognition confidence value exceeds a threshold.
If the recorded utterance is identified as an STT command, the electronic device performs a function based on the STT command. If the electronic device performs the correct function (i.e., the function associated with the command), then the device trains the noise-based VR model database to associate the utterance with the command.
This method may also be repeatedly performed during the STT command mode for the same speech phrase recorded from the same person combined with different noise environments. Examples of noise environments include a home, a car, a street, an office, and a restaurant.
When the current disclosure refers to modules and other elements “providing” information (data) to one another, it is to be understood that there are a variety of possible ways such action may be carried out, including electrical signals being transmitted along conductive paths (e.g., wires) and inter-object method calls.
The embodiments described herein are usable in the context of always-on audio (AOA). When using AOA, an electronic device is capable of waking up from a sleep mode upon receiving a trigger command from a user. AOA places additional demands on devices, especially mobile devices. AOA is most effective when the electronic device is able to recognize the user's voice commands accurately and quickly
Referring to
Although
The device 102 is intended to be representative of a variety of devices including, for example, cellular telephones, personal digital assistants (PDAs), smart phones, or other handheld or portable electronic devices. In alternate embodiments, the device can also be a headset (e.g., a Bluetooth headset), MP3 player, battery-powered device, a watch device (e.g., a wristwatch) or other wearable device, radio, navigation device, laptop or notebook computer, netbook, pager, PMP (personal media player), DVR (digital video recorders), gaming device, camera, e-reader, e-book, tablet device, navigation device with video capable screen, multimedia docking station, or other device.
Embodiments of the present disclosure are intended to be applicable to any of a variety of electronic devices that are capable of or configured to receive voice input or other sound inputs that are indicative or representative of vocalized information.
Further, in the embodiment of
By contrast, the WLAN transceiver 205 is configured to conduct communications in accordance with the IEEE 802.11(a, b, g, or n) standard with access points. In other embodiments, the WLAN transceiver 205 can instead (or in addition) conduct other types of communications commonly understood as being encompassed within WLAN communications such as some types of peer-to-peer (e.g., Wi-Fi Peer-to-Peer) communications. Further, in other embodiments, the Wi-Fi transceiver 205 can be replaced or supplemented with one or more other wireless transceivers configured for non-cellular wireless communications including, for example, wireless transceivers employing ad hoc communication technologies such as HomeRF (radio frequency), Home Node B (3G femtocell), Bluetooth and/or other wireless communication technologies such as infrared technology.
Although in the present embodiment, the device 102 has two of the wireless transceivers 202 (that is, the transceivers 203 and 205), the present disclosure is intended to encompass numerous embodiments in which any arbitrary number of wireless transceivers employing any arbitrary number of communication technologies are present. By virtue of the use of the wireless transceivers 202, the device 102 is capable of communicating with any of a variety of other devices or systems (not shown) including, for example, other mobile devices, web servers, cell towers, access points, other remote devices, etc. Depending upon the embodiment or circumstance, wireless communication between the device 102 and any arbitrary number of other devices or systems can be achieved.
Operation of the wireless transceivers 202 in conjunction with other internal components of the device 102 can take a variety of forms. For example, operation of the wireless transceivers 202 can proceed in a manner in which, upon reception of wireless signals, the internal components of the device 102 detect communication signals and the transceivers 202 demodulate the communication signals to recover incoming information, such as voice and/or data, transmitted by the wireless signals. After receiving the incoming information from the transceivers 202, the computing processor 204 formats the incoming information for the one or more output devices 208. Likewise, for transmission of wireless signals, the computing processor 204 formats outgoing information, which can but need not be activated by the input devices 210, and conveys the outgoing information to one or more of the wireless transceivers 202 for modulation so as to provide modulated communication signals to be transmitted.
Depending upon the embodiment, the input and output devices 208 and 210 of the device 102 can include a variety of visual, audio and/or mechanical outputs. For example, the output device(s) 208 can include one or more visual output devices 216 such as a liquid crystal display and/or light emitting diode indicator, one or more audio output devices 218 such as a speaker, alarm, and/or buzzer, and/or one or more mechanical output devices 220 such as a vibrating mechanism. The visual output devices 216 among other things can also include a video screen. Likewise, by example, the input device(s) 210 can include one or more visual input devices 222 such as an optical sensor (for example, a camera lens and photosensor), one or more audio input devices 224 such as the microphone 108 of
As mentioned above, the device 102 also can include one or more of various types of sensors 228 as well as a sensor hub to manage one or more functions of the sensors. The sensors 228 may include, for example, proximity sensors (e.g., a light detecting sensor, an ultrasound transceiver or an infrared transceiver), touch sensors, altitude sensors, and one or more location circuits/components that can include, for example, a Global Positioning System (GPS) receiver, a triangulation receiver, an accelerometer, a tilt sensor, a gyroscope, or any other information collecting device that can identify a current location or user-device interface (carry mode) of the device 102. Although the sensors 228 for the purposes of
The memory 206 can encompass one or more memory devices of any of a variety of forms (e.g., read-only memory, random access memory, static random access memory, dynamic random access memory, etc.), and can be used by the computing processor 204 to store and retrieve data. In some embodiments, the memory 206 can be integrated with the computing processor 204 in a single device (e.g., a processing device including memory or processor-in-memory (PIM)), albeit such a single device will still typically have distinct portions/sections that perform the different processing and memory functions and that can be considered separate devices. In some alternate embodiments, the memory 206 of the device 102 can be supplemented or replaced by other memory(s) located elsewhere apart from the device 102 and, in such embodiments, the device 102 can be in communication with or access such other memory device(s) by way of any of various communications techniques, for example, wireless communications afforded by the wireless transceivers 202, or connections via the component interface 212.
The data that is stored by the memory 206 can include, but need not be limited to, operating systems, programs (applications), modules, and informational data. Each operating system includes executable code that controls basic functions of the device 102, such as interaction among the various components included among the internal components of the device 102, communication with external devices via the wireless transceivers 202 and/or the component interface 212, and storage and retrieval of programs and data, to and from the memory 206. As for programs, each program includes executable code that utilizes an operating system to provide more specific functionality, such as file system service and handling of protected and unprotected data stored in the memory 206. Such programs can include, among other things, programming for enabling the device 102 to perform a process such as the process for speech recognition shown in
Referring to
The device 102 is capable of accessing a network such as the Internet. While the figure shows direct coupling of components such as audio input device 224, audio output device 218, etc., the connection to the computing processor 204 may be through other components or circuitry in the device. Additionally, utterances and noise that the device 102 captures may be temporarily stored in the memory 206, or more persistently in the utterance database 309 and noise database 310, respectively. Whether stored temporarily or not, the utterances and noises can be subsequently accessed by the computing processor 204. The computing processor 204 may reside external to the electronic device 102, such as on a server on the internet.
The computing processor 204 executes a speech recognition engine 305, which may be resident in the memory 206, and which has access to the noise database 310, the utterance database 309, and the VR model database 308. In one embodiment, one or more of the noise database 310, the utterance database 309, the VR model database 308, and the speech recognition engine 305 are stored and executed by a remotely located server 301.
Referring to
At step 402, the electronic device 102 records an utterance of the user's speech including the natural background noise. The recorded utterance and noise may be stored in the utterance database 309 and noise database 310 for future use. At step 404, the speech recognition engine determines whether the utterance is an STT command. In doing so, the speech recognition engine 305 determines the most likely candidate STT command given the utterance. The speech recognition engine 305 assigns a confidence score to that candidate and, if the confidence score is above a predetermined threshold, deems the utterance to be an STT command. Among the factors influencing the confidence score is the methodology used in performing the training. If the utterance is determined not to be an STT command, then the process returns to step 402. If it is determined to be an STT command, the electronic device 102 performs a function based on the STT command at step 406.
At step 408, the electronic device 102 determines whether the function performed is a valid operation. If so, then at step 410, the electronic device 102 trains the VR model database 308 by, for example, associating the user's utterances with the command. This process executed during normal operation allows the electronic device 102 to update the original VR model database 308 to reflect actual usage in multiple environments which naturally include the noise inherent in those environments. The device 102 may also use previously-recorded utterances from the utterance database 309 and previously-recorded noise from the noise database 310 during this training process.
In an alternative embodiment, a “No” response during step 408 will result in the device 102 asking the user to enter the text for the command they wish to execute in step 411. This text and the utterance captured in step 402 will then be used to train and update the VR model database 308.
Referring to
Referring to
The electronic device carries out step 606 at the same time it carries out step 604. At step 606, the electronic device 102 records the user's utterance along with the played noise sample. At step 608, the electronic device 102 stores the acoustically combined noise sample and utterance in volatile memory or in the noise database 310 and the utterance database 309. At step 610, the electronic device 102 trains the VR model database 308 using the combined noise sample and utterance. At step 612, the electronic device 102 updates the VR model database 308.
It can be seen from the foregoing that a method for apparatus for training a voice recognition database has been provided. In view of the many possible embodiments to which the principles of the present discussion may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of the claims. Therefore, the techniques as described herein contemplate all such embodiments as may come within the scope of the following claims and equivalents thereof.
The present claims the benefit of the filing date of U.S. Provisional Patent Application 61/776,793, filed Mar. 12, 2013, the entire contents of which are incorporated by reference; U.S. Provisional Patent Application 61/798,097, filed Mar. 15, 2013, the entire contents of which are incorporated by reference; and U.S. Provisional Patent Application 61/819,985, filed May 6, 2013, the entire contents of which are incorporated by reference.
Number | Name | Date | Kind |
---|---|---|---|
4348550 | Pirz et al. | Sep 1982 | A |
4363102 | Holmgren et al. | Dec 1982 | A |
4656651 | Evans et al. | Apr 1987 | A |
4763350 | Immendorfer et al. | Aug 1988 | A |
4785408 | Britton et al. | Nov 1988 | A |
4805212 | Hase et al. | Feb 1989 | A |
4827500 | Binkerdeet et al. | May 1989 | A |
4827518 | Feustel et al. | May 1989 | A |
4837804 | Akita | Jun 1989 | A |
4876717 | Barron et al. | Oct 1989 | A |
4914692 | Hartwell et al. | Apr 1990 | A |
4979206 | Padden et al. | Dec 1990 | A |
5033088 | Shipman | Jul 1991 | A |
5125024 | Gokeen et al. | Jun 1992 | A |
5127043 | Hunt et al. | Jun 1992 | A |
5136631 | Einhorn et al. | Aug 1992 | A |
5165095 | Borcherding | Nov 1992 | A |
5181237 | Dowden et al. | Jan 1993 | A |
5193110 | Jones et al. | Mar 1993 | A |
5199062 | Von Meister et al. | Mar 1993 | A |
5204894 | Darden | Apr 1993 | A |
5208848 | Pula | May 1993 | A |
5274695 | Green | Dec 1993 | A |
5297183 | Bareis et al. | Mar 1994 | A |
5297194 | Hunt et al. | Mar 1994 | A |
5301227 | Kamei et al. | Apr 1994 | A |
5353336 | Hou et al. | Oct 1994 | A |
5369685 | Kero | Nov 1994 | A |
5452340 | Engelbeck et al. | Sep 1995 | A |
5479489 | O'Brien | Dec 1995 | A |
5479491 | Herrero-Garcia et al. | Dec 1995 | A |
5517566 | Smith et al. | May 1996 | A |
5652789 | Miner et al. | Jul 1997 | A |
5657422 | Janiszewski | Aug 1997 | A |
5717738 | Gammel | Feb 1998 | A |
5719921 | Vysotsky et al. | Feb 1998 | A |
5799273 | Mitchell et al. | Aug 1998 | A |
5805672 | Barkat et al. | Sep 1998 | A |
5832063 | Vysotsky et al. | Nov 1998 | A |
5893059 | Raman | Apr 1999 | A |
5912949 | Chan et al. | Jun 1999 | A |
5915001 | Uppaluru | Jun 1999 | A |
5953700 | Kanesky et al. | Sep 1999 | A |
5956683 | Jacobs et al. | Sep 1999 | A |
5960399 | Barclay et al. | Sep 1999 | A |
5970446 | Goldberg et al. | Oct 1999 | A |
5995826 | Cox et al. | Nov 1999 | A |
6016336 | Hanson | Jan 2000 | A |
6021181 | Miner et al. | Feb 2000 | A |
6094476 | Hunt et al. | Jul 2000 | A |
6118866 | Shtivelman | Sep 2000 | A |
6144667 | Doshi et al. | Nov 2000 | A |
6144938 | Surace et al. | Nov 2000 | A |
6157705 | Perrone | Dec 2000 | A |
6163608 | Romesburg | Dec 2000 | A |
6167117 | Will | Dec 2000 | A |
6167118 | Slivensky | Dec 2000 | A |
6185535 | Hedin et al. | Feb 2001 | B1 |
6212408 | Son et al. | Apr 2001 | B1 |
6259772 | Stephens et al. | Jul 2001 | B1 |
6259786 | Gisby | Jul 2001 | B1 |
6260012 | Park | Jul 2001 | B1 |
6282511 | Mayer | Aug 2001 | B1 |
6323306 | Song et al. | Nov 2001 | B1 |
6327343 | Epstein et al. | Dec 2001 | B1 |
6347085 | Kelly | Feb 2002 | B2 |
6363348 | Besling et al. | Mar 2002 | B1 |
6363349 | Urs et al. | Mar 2002 | B1 |
6366886 | Dragosh et al. | Apr 2002 | B1 |
6389393 | Gong | May 2002 | B1 |
6400806 | Uppaluru | Jun 2002 | B1 |
6404876 | Smith et al. | Jun 2002 | B1 |
6408272 | White et al. | Jun 2002 | B1 |
6418411 | Gong | Jul 2002 | B1 |
6442519 | Kanevsky et al. | Aug 2002 | B1 |
6449496 | Beith et al. | Sep 2002 | B1 |
6453020 | Hughes et al. | Sep 2002 | B1 |
6456699 | Burg et al. | Sep 2002 | B1 |
6463413 | Applebaum et al. | Oct 2002 | B1 |
6487534 | Thelen et al. | Nov 2002 | B1 |
6493433 | Clabaugh et al. | Dec 2002 | B2 |
6493673 | Ladd et al. | Dec 2002 | B1 |
6501832 | Saylor et al. | Dec 2002 | B1 |
6507643 | Groner | Jan 2003 | B1 |
6574599 | Lim et al. | Jun 2003 | B1 |
6633846 | Bennett et al. | Oct 2003 | B1 |
6650738 | Pershan et al. | Nov 2003 | B1 |
6690772 | Naik et al. | Feb 2004 | B1 |
6693893 | Ehlinger | Feb 2004 | B1 |
6744860 | Schrage | Jun 2004 | B1 |
6744861 | Pershan et al. | Jun 2004 | B1 |
6792083 | Dams et al. | Sep 2004 | B2 |
6823306 | Reding et al. | Nov 2004 | B2 |
6915262 | Reding et al. | Jul 2005 | B2 |
6941264 | Konopka et al. | Sep 2005 | B2 |
6959276 | Droppo | Oct 2005 | B2 |
7725315 | Hetherington | May 2010 | B2 |
7949522 | Hetherington | May 2011 | B2 |
8027833 | Hetherington | Sep 2011 | B2 |
8504362 | Lee | Aug 2013 | B2 |
20020059066 | O'Hagan | May 2002 | A1 |
20020065657 | Reding et al. | May 2002 | A1 |
20050071159 | Boman | Mar 2005 | A1 |
20050119883 | Miyazaki | Jun 2005 | A1 |
20060053014 | Yoshizawa | Mar 2006 | A1 |
20060253283 | Jabloun | Nov 2006 | A1 |
20080300871 | Gilbert | Dec 2008 | A1 |
20090187402 | Scholl | Jul 2009 | A1 |
20090271188 | Agapi | Oct 2009 | A1 |
20100204988 | Xu | Aug 2010 | A1 |
20110208518 | Holtel | Aug 2011 | A1 |
20140064514 | Mikami | Mar 2014 | A1 |
Number | Date | Country |
---|---|---|
1199708 | Apr 2002 | EP |
1262953 | Dec 2005 | EP |
Entry |
---|
Office Action issued in U.S. Appl. No. 11/767,853 on Aug. 14, 2012, 8 pages. |
Office Action issued in U.S. Appl. No. 11/767,853 on Feb. 28, 2011, 25 pages. |
Notice of Allowance issued in U.S. Appl. No. 09/309,274 on Apr. 6, 2007, 6 pages. |
Office Action issued in U.S. Appl. No. 09/309,274 on Nov. 29, 2006, 16 pages. |
Office Action issued in U.S. Appl. No. 09/309,274 on May 10, 2006, 17 pages. |
Office Action issued in U.S. Appl. No. 09/309,274 on Jun. 21, 2004, 15 pages. |
Office Action issued in U.S. Appl. No. 09/309,274 on Oct. 22, 2003, 17 pages. |
Office Action issued in U.S. Appl. No. 09/309,274 on Mar. 11, 2003, 17 pages. |
Office Action issued in U.S. Appl. No. 09/309,274 on Oct. 3, 2002, 17 pages. |
Notice of Allowance issued in U.S. Appl. No. 11/767,853 on Oct. 10, 2012, 6 pages. |
Office Action issued in U.S. Appl. No. 13/611,989 on May 2, 2013, 19 pages. |
Notice of Allowance issued in U.S. Appl. No. 13/611,989 on Jun. 24, 2013, 6 pages. |
Office Action issued in U.S. Appl. No. 13/932,411 on Sep. 27, 2013, 16 pages. |
Office Action issued in U.S. Appl. No. 13/932,411 on Jan. 6, 2014, 5 pages. |
Office Action issued in U.S. Appl. No. 13/932,411 on Jun. 30, 2014, 6 pages. |
Office Action issued in U.S. Appl. No. 09/726,972 on Apr. 9, 2003, 21 pages. |
Office Action issued in U.S. Appl. No. 09/726,972 on Dec. 19, 2003, 13 pages. |
Office Action issued in U.S. Appl. No. 10/961,781 on Nov. 28, 2006, 16 pages. |
Office Action issued in U.S. Appl. No. 10/961,781 on Jul. 23, 2007, 16 pages. |
Office Action issued in U.S. Appl. No. 13/340,954 on Feb. 28, 2012, 18 pages. |
Office Action issued in U.S. Appl. No. 13/340,954 on Jul. 3, 2012, 12 pages. |
Office Action issued in U.S. Appl. No. 13/614,982 on Dec. 21, 2012, 19 pages. |
Notice of Allowance issued in U.S. Appl. No. 13/340,954 on Jan. 28, 2013, 9 pages. |
Notice of Allowance issued in U.S. Appl. No. 13/614,982 on Apr. 26, 2013, 9 pages. |
Office Action issued in U.S. Appl. No. 13/922,602 on Oct. 24, 2013, 22 pages. |
Office Action issued in U.S. Appl. No. 13/922,602 on Apr. 4, 2014, 16 pages. |
Notice of Allowance issued in U.S. Appl. No. 13/922,602 on Jun. 18, 2014, 10 pages. |
Ming et al., “Robust Speaker Recognition in Noisy Conditions,” IEEE Transactions on Audio, Speech and Language Processing, IEEE Service Center, New York, NY, USA, vol. 15, No. 5, Jul. 1, 2007, pp. 1711-1723. |
Ding et al., “Robust mandarin speech recognition in car environments for embedded navigation system,” IEEE Transactions on Consumer Electronics, IEEE Service Center, New York, NY, US, vol. 54, No. 2, May 1, 2008, pp. 584-590. |
Sasou et al., “Noise Robust Speech Recognition Applied to Voice-Driven Wheelchair,” EURASIP Journal on Advances in Signal Processing, vol. 20, No. 3, Jan. 1, 2009, pp. 1-9. |
International Search Report and Written Opinion in International Application No. PCT/US2014/035117, mailed Nov. 12, 2014, 13 pages. |
International Preliminary Report on Patentability in International Application No. PCT/US2014/035117, mailed Nov. 19, 2015, 8 pages. |
Number | Date | Country | |
---|---|---|---|
20140278420 A1 | Sep 2014 | US |
Number | Date | Country | |
---|---|---|---|
61776793 | Mar 2013 | US | |
61798097 | Mar 2013 | US | |
61819985 | May 2013 | US |