PATENT DOCUMENT

Publication Number: US-9264823-B2
Application Number: US-201213631475-A
Country: US
Kind Code: B2

Title: Audio headset with automatic equalization

Abstract:
An accessory having an earbud for insertion into a user&#39;s ear is disclosed. The earbud may include a speaker and a microphone in which the speaker plays an audio signal for the user and the microphone receives the audio signal. The accessory includes a processor that is coupled to the speaker and the microphone to execute various operations. For example, the operations may include: determining a ratio of an energy estimation of the speaker audio signal to an energy estimation of the audio signal received by the microphone; determining a gain for the speaker audio signal based upon the ratio; based upon the gain, selecting a shelving filter; and applying the shelving filter to the speaker audio signal.

Claims:
What is claimed is: 
     
       1. An audio system comprising:
 an earbud configured for insertion into a user&#39;s ear, the earbud including a speaker and a microphone, wherein the speaker is configured to receive and play an audio speaker signal for the user and the microphone is configured to output an audio microphone signal; and 
 a processor coupled to the speaker and the microphone to 
 determine a ratio of (1) an energy estimation of the audio speaker signal to (2) an energy estimation of the audio microphone signal, at low frequencies, 
 determine a ratio of (1) an energy estimation of the audio speaker signal to (2) an energy estimation of the audio microphone signal, at high frequencies, wherein the high frequencies are within 1 kHz to 10 kHz, 
 determine a gain based upon both the ratio at low frequencies and the ratio at high frequencies, 
 based upon the gain, select a shelving filter, and 
 apply the shelving filter to the audio speaker signal. 
 
     
     
       2. The system of  claim 1 , wherein the shelving filter is a low frequency shelving filter having a knee between 100 Hz and 1 kHz and wherein a gain of the shelving filter in the low frequencies is selected based on the determined gain. 
     
     
       3. The system of  claim 1 , wherein the shelving filter is an infinite impulse response (IIR) filter. 
     
     
       4. The system of  claim 1 , wherein the processor is to smooth a) the ratio at low frequencies of (1) the energy estimation of the audio speaker signal to (2) the energy estimation of the audio microphone signal, and b) the ratio at high frequencies of (1) the energy estimation of the audio speaker signal to (2) the energy estimation of the audio microphone signal. 
     
     
       5. The system of  claim 1 , wherein the processor determines the ratio at low frequencies and the ratio at high frequencies using bandpass filters wherein the low frequencies are within 100 Hz to 1 kHz and the high frequencies are within 1 kHz to 10 kHz. 
     
     
       6. A method comprising:
 determining a ratio of (1) an energy estimation of an audio speaker signal that is input to a speaker of an earbud to (2) an energy estimation of an audio microphone signal that is output by a microphone of the earbud, at low frequencies; 
 determining a ratio of (1) an energy estimation of the audio speaker signal to (2) an energy estimation of the audio microphone signal, at high frequencies, wherein the high frequencies are within 1 kHz to 10 kHz, 
 determining a gain based upon both the ratio at the low frequencies and the ratio at the high frequencies; 
 based upon the gain, selecting a shelving filter; and 
 applying the shelving filter to the audio speaker signal. 
 
     
     
       7. The method of  claim 6 , wherein the shelving filter is a low frequency shelving filter having a knee between 100 Hz and 1 kHz and wherein a gain of the shelving filter in the low frequencies is selected based on the determined gain. 
     
     
       8. The method of  claim 6 , wherein the shelving filter is an infinite impulse response (IIR) filter. 
     
     
       9. The method of  claim 6 , wherein determining the gain based upon both the ratio at low frequencies and the ratio at high frequencies comprises smoothing the ratio at low frequencies and smoothing the ratio at high frequencies. 
     
     
       10. The method of  claim 6 , wherein determining the ratios at low frequencies and at high frequencies comprises filtering the audio speaker signal and the audio microphone signal using bandpass filters, wherein the low frequencies are within 100 Hz to 1 kHz and the high frequencies are within 1 kHz to 10 kHz. 
     
     
       11. A non-transitory processor-readable storage medium comprising codes executable by a processor to:
 determine a ratio of (1) an energy estimation of an audio speaker signal that is input to a speaker of an earbud to (2) an energy estimation of an audio microphone signal that is output by a microphone of the earbud, at low frequencies; 
 determine a ratio of (1) an energy estimation of the audio speaker signal to (2) an energy estimation of the audio microphone signal, at high frequencies, wherein the high frequencies are within 1 kHz to 10 kHz; 
 determine a gain based upon both the ratio at low frequencies and the ratio at high frequencies; 
 based upon the gain, select a shelving filter; and 
 apply the shelving filter to the audio speaker signal. 
 
     
     
       12. The non-transitory processor-readable storage medium of  claim 11 , wherein the shelving filter is a low frequency shelving filter having a knee between 100 Hz and 1 kHz and wherein a gain of the shelving filter in the low frequencies is selected based on the determined gain. 
     
     
       13. The non-transitory processor-readable storage medium of  claim 11 , wherein the shelving filter is an infinite impulse response (IIR) filter. 
     
     
       14. The non-transitory processor-readable storage medium of  claim 11 , further comprising code to smooth the ratio at low frequencies of (1) the energy estimation of the audio speaker signal to (2) the energy estimation of the audio microphone signal and code to smooth the ratio at high frequencies of (1) the energy estimation of the audio speaker signal to (2) the energy estimation of the audio microphone signal. 
     
     
       15. The non-transitory processor-readable storage medium of  claim 11 , further comprising code to bandpass filter the audio speaker signal and the audio microphone signal, when determining the ratios at low frequencies and at high frequencies, wherein the low frequencies are within 100 Hz to 1 kHz and the high frequencies are within 1 kHz to 10 Hz.

Description:
FIELD 
     An embodiment of the invention relates to an audio headset with automatic equalization. 
     BACKGROUND 
     It is often desirable to use headphones when listing to music and other audio material. For example, users commonly use headphones when listening to music that is being played back from a portable music player. Over-the-ear headphones are sometimes used, particularly in environments in which size is not a major concern. When a compact size is desired, users often use in-ear headphones (sometimes termed “earbuds”). Earbuds are popular because they form a seal in the ear that helps to reduce ambient noise while retaining the compact size of other in-ear designs. 
     When earbuds are used by different people, there are variances in frequency response at the Drum Reference Point (DRP). These variances may be caused by different amounts of occlusion that the headphone creates when it is placed in the user&#39;s ear, which may be the result of the following factors: 1) inconsistency in the positioning of the headphone in the user&#39;s ear; 2) different sizes/shapes of the user&#39;s ears; and 3) the headphone moving in the user&#39;s ear due to stress, shaking, jogging, etc. Accordingly, it would be beneficial to compensate for these variances and provide a consistent response at the DRP. 
     SUMMARY 
     An embodiment of the invention relates to an accessory having an earbud for insertion into a user&#39;s ear. The earbud may include a speaker and a microphone in which the speaker plays an audio signal for the user and the microphone receives the audio signal. The accessory may include a processor that is coupled to the speaker and the microphone to execute various operations. For example, the operations may include: determining a ratio of an energy estimation of the speaker audio signal to an energy estimation of the audio signal received by the microphone; determining a gain for the speaker audio signal based upon the ratio; based upon the gain, selecting a shelving filter; and applying the shelving filter to the speaker audio signal. 
     By applying the shelving filter to the speaker audio signal, an equalized speaker audio signal is sent out in the user&#39;s ear to compensate for gain/loss due to occlusions associated with the headphone and the user&#39;s ear such that these factors are compensated for and the user receives the intended speaker audio signal. 
     The above summary does not include an exhaustive list of all aspects of the present invention. It is contemplated that the invention includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the Detailed Description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above summary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment of the invention in this disclosure are not necessarily to the same embodiment, and they mean at least one. 
         FIG. 1  is a perspective view of an illustrative system that includes an electronic device and an associated headset in accordance with an embodiment of the invention. 
         FIG. 2  is a block diagram showing circuitry that may be used in an electronic device and headset accessory in a system of the type shown in  FIG. 1  in accordance with an embodiment of the invention. 
         FIG. 3  is a flow diagram illustrating a process of adaptive equalization (EQ) for an earbud, according to one embodiment of the invention. 
         FIG. 4  is a chart illustrating selectable shelving filters, according to one embodiment of the invention. 
         FIG. 5  is a chart illustrating reduced variances when embodiments of the invention related to adaptive EQ are implemented. 
     
    
    
     DETAILED DESCRIPTION 
     Several embodiments of the invention with reference to the appended drawings are now explained. While numerous details are set forth, it is understood that some embodiments of the invention may be practiced without these details. In other instances, well-known circuits, structures, and techniques have not been shown in detail so as not to obscure the understanding of this description. 
     Electronic devices such as computers, cellular telephones, and portable music players are often connected to headphones and other accessories with speakers. In a typical arrangement, a headset has a cable that is plugged into an audio jack in an electronic device. The headset has speakers that are used to play back audio material from the electronic device. For example, the headset may play a song for a user of a music player or may be used to present telephone call audio signals to the user of a cellular telephone. 
     Earbud headsets have speakers that are housed in earbuds. The earbuds may have elastomeric features that conform to the ear canal of a user&#39;s ear. For example, an earbud may have a foam structure or soft plastic fins that help seat the earbud in the user&#39;s ear. When properly positioned in the user&#39;s ear, the earbud forms a seal with the user&#39;s ear. The seal blocks ambient noise. The seal also forms an enclosed cavity adjacent to the ear. 
     For example, with reference to  FIG. 1 , a system  8  is shown that may include an electronic device  10  and may include an accessory such as headset  18 . Device  10  may be a cellular telephone with media playback capabilities, a portable computer such as a tablet computer or laptop computer, a desktop computer, a television, an all-in-one computer that is housed in the case of a computer monitor, television equipment, an amplifier, or any other suitable electronic equipment. Device  10  may have input-output components such as button  12  and display  14 . Display  14  may be a touch screen or a display without touch capabilities. 
     Accessory  18  may be a headset or other device that includes speakers. Accessory  18  may, for example, be a headset that includes a voice microphone for handling telephone calls, a pair of stereo headphones that contains speakers but that does not include a voice microphone, a single-speaker device such as a wireless earpiece, hearing aid, or monaural headphone, etc. Arrangements in which accessory  18  is implemented using one or more earbud-styles speakers (i.e., arrangements in which accessory  18  is a set of earbud headphones) are sometimes described herein as an example. 
     In the example of  FIG. 1 , headset  18  has earbuds  24 . Button assembly  26  may include user-controlled buttons and an optimal voice microphone. Circuitry for headset  18  may be housed in button assembly  26  or in earbuds  24  (as examples). If desired, headset  18  may have different types of user input interfaces (e.g., interfaces based on microphones, touch screens, touch sensors, switches, etc.). The inclusion of button assembly  26  in headset  18  of  FIG. 1  is merely illustrative. 
     Cables such as cables  22  may be used to interconnect earbuds  24 , button assembly  26 , and plug  20 . Plug  20  may be implemented using an audio plug (e.g., a 3.5 mm tip-ring-ring-sleeve or tip-ring-sleeve connector), using a digital connector (e.g., a universal serial bus connector or a 30-pin data port connector), or using any other suitable connector. Connector  20  may have contacts that mate with corresponding contacts in port  16 . For example, if connector  20  is a four-contact 3.5 mm audio plug, port  16  may be a mating four-contact 3.5 mm audio jack. 
     Circuitry that may be used in device  10  and headset  18  of  FIG. 1  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include control circuitry  28  and accessory  18  may include control circuitry  34 . Circuitry  28  and  34  may include storage and processing circuitry that is based on microprocessors, application-specific integrated circuits, audio chips (codecs), video integrated circuits, microcontrollers, digital signal processors (e.g., audio digital signal processors), memory devices such as solid state storage, volatile memory (e.g., random-access memory), and hard disk drives, etc. 
     As shown in  FIG. 2 , circuitry  28  may, if desired, include audio processing circuitry  30 . Circuitry  34  may also include audio processing circuitry  36 , if desired. Circuitry  28  may include input-output circuitry  32 . Circuitry  34  may also include input-output circuitry  38 . Input-output circuitry  32  and  38  may include user input devices such as buttons, touch pads, track pads, keyboards, switches, microphones, and touch screens. Input-output circuitry may also include output devices such as displays, speakers, and status indicators. Input-output circuitry  32  and  38  may include communications circuitry that is associated with ports such as port  16  of device  10  and plug  20  of accessory  18 . This communications circuitry may be used to transmit analog and/or digital signals between device  10  and headset  18 . Cables such as cable  22  and connectors such as connectors  16  and  20  may form a communications path that can be used in conveying signals between device  10  and headset  18 . The communications path may be used to transmit audio from circuitry  28  to earbuds  24  during playback operations. 
     As one example, each of the earbuds  24  may include a speaker and a microphone that is placed in a user&#39;s ear. The speaker plays an audio signal for the user and the microphone receives the audio signal. The audio processing circuitry  36  of headset  18  is coupled to both the speaker and the microphone. The audio processing circuitry  36  (e.g., hereinafter referred to as processor) may execute operations including: determining a ratio of an energy estimation of the speaker audio signal to an energy estimation of the audio signal received by the microphone; determining a gain for the speaker audio signal based upon the ratio; and based upon the gain, selecting a shelving filter. The processor  36  further applies the shelving filter to the speaker audio signal. By applying the shelving filter to the speaker audio signal an equalized speaker audio signal is sent out in the user&#39;s ear to compensate for gain/loss due to occlusions associated with the headphone and the user&#39;s ear. For example, the shelving filter may be a low frequency infinite impulse response (IIR) filter. 
     In general, this method of adaptive of adaptive equalization (EQ) includes a microphone integrated into the earbud in front of the speaker in order to detect the frequency response in the ear. An error microphone signal is compared to the signal being sent to the speaker. Based on these two signals, an appropriate EQ curve is computed and applied to the signal being sent to the speaker. 
     With additional reference to  FIG. 3 , a process implemented by processor  36  of an earbud  24  is illustrated. In particular, a device  10  transmits an audio signal to an earbud  24  that includes a speaker  310  and a microphone  315 . Speaker  310  plays an audio signal for the user and the microphone  315  receives the audio signal as it is bounced around within the user&#39;s ear. The processor  36  is coupled to the speaker  310  and microphone  315  to execute operations. In particular, as will be described hereinafter, these operations include: determining a ratio of an energy estimation of the speaker audio signal to an energy estimation of the audio signal received by the microphone  315  (e.g., blocks  340 ,  370 ); determining a gain (e.g., block  380 ) for the speaker audio signal based upon the ratios; and based upon the gain, selecting a shelving filter (e.g., block  382 ). 
     To begin with, the process first receives the audio signal at decision block  300 , where it is determined whether the adaptive equalization (EQ) process is to be implemented. If not, it is bypassed. If the adaptive EQ process is to be implemented, then at block  302 , the adaptive EQ process is implemented as will be described. This bypass may be utilized with the system to help stabilize it, but is not necessary. 
     In order to implement the process under the control of the processor, the audio signal to the speaker is analyzed both at low frequency and high frequency. Looking first at low frequency analysis (e.g., 10-1000 Hz), the audio signal is filtered by a low frequency bandpass filter  330 . Next, the filtered signal undergoes energy estimation  332  to determine an energy estimation of the audio signal. This energy estimation may be an averaging energy estimate over a pre-defined period of time for the audio signal. It should be appreciated that a FIR and/or IIR filter may be utilized to estimate a moving average energy estimate. The energy estimate may then be smoothed at smoothing block  334 . Smoothing is beneficial in that it provides a more stable estimate. The smoothed energy estimate is then transmitted to ratio block  340 , as will be described. 
     Simultaneously, an energy estimation of the audio signal at low frequency received by the microphone  315  is estimated. First, at block  320 , it is determined whether an audio signal is present. If not, the adaptive EQ process or algorithm is bypassed (block  322 ). This bypass may be utilized with the system to help stabilize it (i.e., if microphone  315  becomes non-operational), but is not necessary. However, if the audio signal is received by the microphone  315 , the audio signal is filtered by a low frequency bandpass filter  324 . Next, the filtered signal undergoes energy estimation  326  to determine an energy estimation of the audio signal. This energy estimation may be an averaging energy estimate over a pre-defined period of time for the audio signal. It should be appreciated that a FIR and/or IIR filter may be utilized to estimate a moving average energy estimate. The energy estimate may then be smoothed at smoothing block  328 . Smoothing is beneficial in that it provides a more stable estimate. The smoothed energy estimate is then transmitted to ratio block  340 . 
     At block  340 , a ratio of the energy estimation of the speaker audio signal from the speaker  310  to the energy estimation of the audio signal received by the microphone  315  is determined. This is denoted as speaker/microphone. Also, this is based upon low frequency bandpass filter energy estimates. This ratio of the energy estimation of the speaker audio signal from the speaker  310  to the energy estimation of the audio signal received by the microphone  315  is then smoothed by block  341  and is transmitted to the gain adjustment determiner  380 , as will be described. 
     Simultaneous to the determining of the ratio of the energy estimation of the speaker audio signal to the energy estimation of the audio signal received by the microphone  315 , at low frequencies, the same methodology is applied at high frequencies, as well (e.g., 1 K-10 K Hz). In this process, the audio signal is filtered by a high frequency bandpass filter  360 . Next, the filtered signal undergoes energy estimation  362  to determine an energy estimation of the audio signal. This energy estimation may be an averaging energy estimate over a pre-defined period of time for the audio signal. It should be appreciated that a FIR and/or IIR filter may be utilized to estimate a moving average energy estimate. The energy estimate may then be smoothed at smoothing block  364 . Smoothing is beneficial in that provides a more stable estimate. The smoothed energy estimate is then transmitted to ratio block  370 , as will be described. Similarly, an energy estimation of the audio signal at high frequency received by the microphone  315  is estimated. The audio signal is filtered by a high frequency bandpass filter  350 . Next, the filtered signal undergoes energy estimation  352  to determine an energy estimation of the audio signal. The energy estimate may then be smoothed at smoothing block  351 . The smoothed energy estimate is then transmitted to ratio block  370 . 
     At block  370 , a ratio of the energy estimation of the speaker audio signal from the speaker  310  to the energy estimation of the audio signal received by the microphone  315  is determined. This is denoted as speaker/microphone. This is based upon high frequency bandpass filter energy estimates. This ratio of the energy estimation of the speaker audio signal from the speaker  310  to the energy estimation of the audio signal received by the microphone  315  is then smoothed by block  371  and is transmitted to the gain adjustment determiner  380 . 
     The gain adjustment determiner  380  determines a gain that should be applied to the speaker audio signal for output by the speaker  310  such that the received audio signal (as heard by the microphone  315 ) is equalized and substantially the same as the intended speaker audio signal out of the speaker  310  (i.e., it is adaptively equalized (block  302 )). The gain for the speaker audio signal is determined by both the ratios of the energy estimates of the speaker to the energy estimation of the audio signal received by the microphone both at the low frequency level (block  340 ) and at the high frequency level (block  370 ). Also, it should be noted that cross-correlation  318  may be utilized between the speaker and microphone signals in order to prevent the process from adjusting the gain on signals picked up by the error microphone  315  that do not originate from the speaker (e.g., background noise, user&#39;s voice, etc.). 
     Based upon the desired gain, at block  382 , the processor selects an appropriate shelving filter to obtain the desired gain. As an example, the shelving filter may be a second order shelving filter. With additional reference to  FIG. 4 , as shown by graph  400 , a range of shelving filters  402 - 1  through  402 -N may be selected to obtain the desired gain. Continuing with process, at block  384  of  FIG. 3 , the selected shelving filter is applied in the adaptive equalization  302  such that the received audio signal (as heard by the microphone  315 ) is equalized and substantially the same as the intended speaker audio signal out of the speaker  310  (i.e., it is adaptively equalized (block  302 )). 
     Accordingly, this previously described process may take advantage of the fact that most of the frequency response invariability at the Drum Reference Point (DRP) occur at the low frequencies. Typically, above 2 kHz, the frequency response remains stable with different fits in the ear—and therefore different amounts of occlusion. However, problems mainly occur at the low frequencies. Therefore, a low-frequency shelving filter (e.g.,  402 - 1  through  402 -N) may be applied in order to compensate for the invariabilities in the frequency response. The shelving filter may have a fixed cut-off frequency of about 1 kHz. The amount of gain applied to lower frequencies depends on the amount of occlusion. As previously described, the microphone  315  may be used in order to estimate the amount of gain to be applied to the low frequencies. In order to obtain this estimate, the process may consider the amount of energy in the low frequencies (e.g., from 100 Hz to 1 kHz) in both the speaker signal that is being sent out from the speaker  310  and the received signal at the microphone  315 . The smoothed ratio of the energy estimates of these two signals may determine the amount of gain to be applied. After the amount of needed gain is determined, the low-frequency shelving filter is selected and applied to the speaker signal. The equalized speaker signal may be sent out in order to compensate for the gain/loss of the occlusion associated with the headphone and the user&#39;s ear. 
     As an example, as can be seen with additional reference to  FIG. 5 , when the previously-described process is implemented, the graph  500  shows that the variances (y-axis) between the desired outputted audio signal and the received audio signal based on the equalization method for tight-fit earbuds  510 , medium-fit earbuds  510 , and loose-fit earbuds (see circle range  502 ), at the lower frequencies (x-axis), are relatively low and consistent with one another. 
     It should be appreciated that this methodology takes advantage of the fact that most of the frequency response invariability at the DRP occurs at the lower frequencies. Above 2 kHz, the frequency response remains stable with different fits in the ear—and therefore different amounts of occlusion. The problems remedied and addressed occur at the lower frequencies. Therefore, by utilizing the previously described low-frequency shelving filters that are applied in order to compensate for the invariability in frequency response, these problems can be addressed. The filters may have a fixed cut-off frequency of about 1 kHz, and above 2 kHz, may have a unity response. The amount of gain applied to lower frequencies depends upon the amount of occlusion. The microphone (built in the headphone in front of the driver) can be used in order to estimate the amount of gain to be applied to the low frequencies. It should be appreciated that the frequencies mentioned above are approximate, and are used to illustrate the principle aspects of the invention. It should also be appreciated that exact values will depend on the acoustics of the overall system including the ear, the earbud, the speaker, and the microphone. 
     In order to obtain this estimate, the previously-described process considers the energy estimates at both low frequencies and high frequencies in both the speaker signal that is being sent out and the received microphone signal. The smoothed ratio of energy estimates of these signals determines the amount of gain to be applied. After the amount of needed gain is determined, the low-frequency shelving filter is selected and applied to the speaker signal. The equalized signal being sent out applies the gain to compensate for loss of the occlusion. This process constantly (e.g., on a pre-determined time interval basis) estimates the energy levels of the signals, computes gains, and applies the correct shelving filter. The shelving filters used for compensation are predesigned and selected based upon the gain that needs to be applied. 
     It should be appreciated that aspects of the invention previously described may be implemented in conjunction with the execution of codes or instructions by a processor and/or other devices. Particularly, circuitry including but not limited to processors, may operate under the control of a program, routine, or the execution of instructions to execute methods or processes in accordance with embodiments of the invention. For example, such a program may be implemented in firmware or software (e.g. stored in memory and/or other locations) and may be implemented by processors and/or other circuitry. Further, it should be appreciated that the terms processor, microprocessor, circuitry, controller, etc., refer to any type of logic or circuitry capable of executing logic, commands, instructions, software, firmware, functionality, etc 
     While certain embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that the invention is not limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those of ordinary skill in the art. For example, although the audio system depicted in the figures may be a smart phone, digital media player, or a tablet computer, the audio system may alternatively be a different portable device such as a laptop computer, or even a non-portable device such as a desktop computer or a home entertainment appliance (e.g., digital media receiver, media extender, media streamer, digital media hub, digital media adapter, or digital media renderer). The description is thus to be regarded as illustrative instead of limiting.

Metadata:
Filing Date: 20120928
Publication Date: 20160216
Grant Date: 20160216
Priority Date: 20120928
Inventors: BAJIC VLADAN
BRIGHT ANDREW P.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R2460/05", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R5/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R3/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R25/505", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/1016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R5/033", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/1083", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R2430/03", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R3/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2460/05", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R25/505", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R5/033", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/1083", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R2430/03", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R5/04", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 50385230