Input selection for reducing wind noise for wearable devices

Abstract

A wind noise reduction system including a beamformer, a comparator, and a voice mixer is provided. The beamformer may be an MVDR beamformer, and a beamformed signal is generated based on the first microphone signal and the second microphone signal. A comparator generates a comparison signal based on the beamformed signal and the wind microphone signal. The comparison signal may also be based on a beamformed energy level of the beamformed signal and a wind energy level of the wind microphone signal. A voice mixer generates an output voice signal based on the beamformed signal, the wind microphone signal, and the comparison signal. The wind noise reduction system may also include a wind microphone corresponding to the wind microphone signal. A wind microphone may be disposed on a portion of the wearable audio device configured to be seated in an outer ear of a wearer.

Description

Technical Field

[0001] The present disclosure generally relates to input selection for reducing wind noise in wearable audio devices. Background Art

[0002] An important aspect of wearable audio devices is the ability to capture the speech audio of the wearer. Whether the captured speech is in the context of a voice call with another person or inputting voice audio commands into an electronic system, the clarity of the voice audio is important for the use of the device. Most wearable audio devices utilize one or more embedded microphones to capture voice audio. However, some devices such as earbuds contain microphones that are exposed to the external environment. These microphones are particularly vulnerable to wind noise, which can drown out the captured voice audio.

[0003] Wearable audio devices that utilize minimum variance distortionless response (MVDR) beamforming may exacerbate the wind noise problem. Beamforming enables the audio sensors of the device to focus audio capture on a specific spatial region such as an area around the wearer's mouth. MVDR beamforming is often preferred due to its high performance in terms of clarity and naturalness, especially in areas with a certain degree of diffuse noise, such as a cafeteria background. However, the characteristics of MVDR beamforming may cause significant amplification of wind noise, sometimes to the point of overwhelming any captured voice audio. Therefore, there is a need for an audio processing system that can reduce the wind noise of wearable audio devices. Summary of the Invention

[0004] The present disclosure generally relates to input selection for reducing wind noise in wearable audio devices.

[0005] Generally, in one aspect, a wind noise reduction system is provided. The wind noise reduction system includes a beamformer. The beamformer is configured to generate a beamformed signal. The beamformed signal is generated based on a first microphone signal and a second microphone signal. The beamformer may be a minimum variance distortionless response (MVDR) beamformer.

[0006] The wind noise reduction system further includes a comparator. The comparator is configured to generate a comparison signal. The comparison signal is generated based on the beamformed signal and a wind microphone signal. The comparison signal may also be based on the beamformed energy level of the beamformed signal and the wind energy level of the wind microphone signal.

[0007] The wind noise reduction system further includes a dynamic voice mixer. The dynamic voice mixer is configured to generate an output voice signal. The output voice signal is generated based on the beamformed signal, the wind microphone signal, and a comparison signal. According to one example, the output voice signal can be a blend of the beamformed signal and the wind microphone signal. The ratio of the wind microphone signal to the beamformed signal in the output voice signal can correspond to the comparison signal. Additionally, the ratio of the wind microphone signal to the beamformed signal in the output voice signal can be frequency-dependent. According to another example, the output voice signal can correspond to the wind microphone signal in a frequency range of 200 Hz to 2 kHz.

[0008] According to one example, the wind noise reduction system may further include a first microphone corresponding to a first microphone signal. The wind noise reduction system may further include a second microphone corresponding to a second microphone signal. The wind noise reduction system may further include a wind microphone corresponding to the wind microphone signal. The wind microphone can be arranged on a portion of the wearable audio device configured to sit on the outer ear of the wearer. Additionally, the wind microphone can face the bottom surface of the wearer's outer ear during use.

[0009] According to one example, the first microphone signal, the second microphone signal, and the wind microphone signal can be frequency domain signals. Alternatively, the first microphone signal, the second microphone signal, and the wind microphone signal can be time domain signals.

[0010] According to one example, the wind noise reduction system may further include an equalizer. The equalizer can be configured to filter the beamformed signal before the beamformed signal is received by the comparator and the dynamic voice mixer.

[0011] According to one example, the wind noise reduction system may further include a high-pass filter. The high-pass filter can be configured to filter the beamformed signal before the beamformed signal is received by the dynamic voice mixer.

[0012] According to one example, the wind noise reduction system may further include a feedforward noise cancellation controller for performing feedforward noise cancellation. The feedforward noise cancellation controller receives an input corresponding to the wind microphone signal.

[0013] Overall, in another aspect, there is provided a wearable audio device. The wearable audio device includes a first microphone. The first microphone is configured to generate a first microphone signal.

[0014] The wearable audio device further includes a second microphone. The second microphone is configured to generate a second microphone signal.

[0015] The wearable audio device further includes a wind microphone. The wind microphone corresponds to a wind microphone signal. The wind microphone can be arranged on a part of the wearable audio device configured to be inserted into the outer ear of the wearer.

[0016] The wearable audio device further includes a beamformer. The beamformer is configured to generate a beamformed signal. The beamformed signal is generated based on a first microphone signal and a second microphone signal.

[0017] The wearable audio device further includes a comparator. The comparator is configured to generate a comparison signal. The comparison signal is generated based on the beamformed signal and the wind microphone signal.

[0018] The wearable audio device further includes a dynamic voice mixer. The dynamic voice mixer is configured to generate an output voice signal. The output voice signal is generated based on the beamformed signal, the wind microphone signal, and the comparison signal.

[0019] According to one example, the wearable audio device can be an earbud.

[0020] Overall, on the other hand, a method for reducing wind noise is provided. The method includes generating a beamformed signal based on a first microphone signal and a second microphone signal via a beamformer. The method further includes generating a comparison signal based on the beamformed signal and the wind microphone signal via a comparator. The method further includes generating an output voice signal based on the beamformed signal, the wind microphone signal, and the comparison signal via a dynamic voice mixer.

[0021] According to another example, the method may further include: (1) generating a first microphone signal via a first microphone; (2) generating a second microphone signal via a second microphone; and (3) generating a wind microphone signal via a wind microphone arranged on a part of the wearable audio device configured to be disposed in the outer ear of the wearer and facing the bottom surface of the outer ear.

[0022] In various embodiments, a processor or controller may be associated with one or more storage media (collectively referred to herein as "memory", such as volatile and non-volatile computer memory, such as ROM, RAM, PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetic tapes, flash memories, OTP-ROMs, SSDs, HDDs, etc.). In some embodiments, the storage media may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform at least some of the functions discussed herein. The various storage media may be fixed within the processor or controller or may be removable, such that one or more programs stored thereon may be loaded into the processor or controller to implement the various aspects discussed herein. The term "program" or "computer program" is used herein in a general sense to refer to any type of computer code (e.g., software or microcode) that can be used to program one or more processors or controllers.

[0023] It should be understood that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (assuming such concepts are not mutually inconsistent) are considered to be part of the inventive subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are considered to be part of the inventive subject matter disclosed herein. It should also be understood that any terms explicitly employed herein that also appear in any disclosure incorporated by reference should be accorded a meaning that most closely conforms to the particular concepts disclosed herein.

[0024] These and other aspects of the various embodiments will be apparent from the embodiments described below and will be elucidated with reference to the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In the drawings, like reference symbols generally refer to the same parts throughout the different views. Additionally, the drawings are not necessarily to scale, and emphasis is generally placed on illustrating the principles of the various examples.

[0026] Figure 1 is an illustration of a wearer of a wearable audio device.

[0027] Figure 2 is an isometric view of a wearable audio device in accordance with aspects of the present disclosure.

[0028] Figure 3 is in accordance with aspects of the present disclosure Figure 2 of a wearable audio device.

[0029] Figure 4 is in accordance with aspects of the present disclosure Figure 2 and Figure 3Another isometric view of the wearable audio device.

[0030] Figure 5 is in accordance with aspects of the present disclosure Figures 2 to 4 Another isometric view of the wearable audio device.

[0031] Figure 6 is a functional block diagram of a frequency domain wind noise reduction system in accordance with aspects of the present disclosure.

[0032] Figure 7 is a functional block diagram of a time domain wind noise reduction system in accordance with aspects of the present disclosure.

[0033] Figure 8 is a flowchart of a method for reducing wind noise in accordance with aspects of the present disclosure. Detailed Description

[0034] The present disclosure generally relates to an input selection for reducing wind noise in a wearable audio device. The wearable audio device captures the spoken voice audio of the wearer via two microphones coupled to a beamformer such as a minimum variance distortionless response (MVDR) beamformer. The wearable audio device also captures the spoken voice audio via a wind microphone. The wind microphone is disposed on a portion of the wearable device configured to sit on the outer ear of the wearer such that the wind microphone faces the bottom surface of the outer ear. Accordingly, the wind microphone will be shielded from wind noise by the structure of the outer ear and the wearer's ear, and thus will perform better than the beamformer in windy conditions. Specifically, in the frequency range of 200 Hz to 2 kHz, the performance of the wind microphone will generally be better than that of the beamformer (in terms of characteristics such as signal-to-noise ratio (SNR) or noise floor level).

[0035] The energy level of the beamformed signal generated by the beamformer is compared with the energy level of the wind microphone signal captured by the wind microphone. The dynamic voice mixer generates an output voice signal by switching (or blending) between the beamformed signal and the wind microphone signal based on the energy level comparison. If the energy level of the beamformed signal is higher than the energy level of the wind microphone signal, then there is a windy condition, and at least a portion of the output voice signal will correspond to the wind microphone signal. Alternatively, if the energy level of the beamformed signal is lower than the energy level of the wind microphone signal, then there is a windless condition, and at least a portion of the output voice signal will correspond to the beamformed signal.

[0036] Figure 1 is an illustration of a wearer W of the wearable audio device 10 (see Figure 2 ). Specifically, Figure 1Illustrates the position of the outer ear C of the ear E of the wearer W. The inner part of the outer ear C is referred to as the bottom surface F. As will be shown in the subsequent figures, a part of the wearable audio device 10 will be seated in the outer ear C such that this part faces the bottom surface F. It should be noted that in windy conditions, this part of the wearable audio device 10 will be shielded from wind noise by the structure of the ear E.

[0037] Figure 2 Is an isometric view of the wearable audio device 10 embodied as an earplug. In this example, the wearable audio device 10 includes an ear tip 14 inserted into the ear canal of the wearer W. The wearable audio device 10 also includes a first microphone 102. The first microphone 102 is arranged on the surface of the wearable audio device 10 such that when the ear tip 14 is inserted into the ear canal, the first microphone 102 generally faces away from the wearer W. The first microphone 102 can be any microphone generally configured to capture the spoken voice audio of the wearer W, such as an omnidirectional microphone.

[0038] Figure 3 Is Figure 2 Of the wearable audio device 10. As Figure 3 Shown, the wearable audio device 10 includes a sound transducer 185 arranged within the ear tip 14. The sound transducer 185 is configured to convert an electrical signal into audio for playback to the wearer W. The wearable audio device 10 also includes a second microphone 104. The second microphone 104 is arranged on the rear surface of the wearable audio device 10 such that when the ear tip 14 is inserted into the ear canal, the second microphone 104 generally faces the wearer. As Figure 2 And Figure 3 Visible in, the first microphone 102 and the second microphone 104 are each exposed to the external environment such that the microphones 102, 104 are each vulnerable to wind noise.

[0039] Like the first microphone 102, the second microphone 104 can be any microphone generally configured to capture the spoken voice audio of the wearer W, such as an omnidirectional microphone. Additionally, as will be described in more detail below, the first microphone 102 and the second microphone 104 can be used together with a beamformer 114 (see Figure 5 And Figure 6 ) to capture the spoken voice audio in a specific spatial region near the wearer W. In a preferred example, the beamformer 114 is an MVDR beamformer.

[0040] As used herein, the term "beamformer" generally refers to a filter or an array of filters used to achieve directional signal transmission or reception. In the examples described in this application, the beamformer combines audio signals received by multiple audio sensors (such as microphones and accelerometers) to focus on a desired spatial region, such as the region around the mouth of the wearer. Although different types of beamformers utilize different types of filtering, beamformers generally achieve directional reception by filtering the received signals such that signals received from the desired spatial region undergo constructive interference when combined, while signals received from the undesired spatial regions undergo destructive interference. This interference causes the signals from the desired spatial region to be amplified and the signals from the undesired spatial regions to be suppressed. The desired constructive and destructive interferences are generally achieved by controlling the phase and / or relative amplitude of the received signals before combination. Filtering can be implemented via one or more integrated circuit (IC) chips such as a field programmable gate array (FPGA). Software can also be used to implement the filtering.

[0041] The wearable audio device 10 also includes a wind microphone 106. The wind microphone 106 is positioned on a portion of the wearable audio device 10 that is configured to sit in the outer ear C of the wearer W such that the wind microphone 106 faces the bottom surface F of the outer ear C. By positioning the wind microphone 106 within the outer ear C, the wind microphone 106 is effectively shielded from wind noise. Thus, in windy conditions, spoken speech audio captured by the wind microphone 106 can preferably be used instead of the audio captured by the first microphone 102 or the second microphone 104. In some examples, the wind microphone 106 can also be used as an input to a feedforward noise cancellation system. In a feedforward noise cancellation system, the audio captured by the wind microphone can be used to remove unwanted noise in the audio played for the wearer W via the acoustic transducer 185. Figure 4 An additional (left side) view of the wearable audio device 10 is shown, which shows the wind microphone 106, the ear tip 14, and the acoustic transducer 185. In some examples, the construction, model, or microphone type of the wind microphone 106 can be the same as or similar to that of the first microphone 102 or the second microphone 104. Thus, the wind microphone 106 can be an omnidirectional microphone.

[0042] Figure 5 is an additional view of the wearable audio device 10. Figure 5 Depicts the internal circuitry 12 of the wearable audio device 10. The internal circuitry 12 includes a wind noise reduction system 100 (shown in more detail in Figure 6 and Figure 7in), a processor 125, a memory 175, and a transceiver 195. The processor 125 can be used to execute various aspects of the wind noise reduction system 100, such as the beamformer 114, the equalizer 130, the high-pass filter 132, the energy detector 138, the energy detector 140, the comparator 118, and / or the voice mixer 122 (see Figure 6 and Figure 7 ). The memory 175 can be configured to store data related to various aspects of the wind noise reduction system 100, such as the programmable filter weights of the beamformer 114, the equalizer 130, or the high-pass filter 132 (see Figure 6 and Figure 7 ). The transceiver 195 can be configured to send or receive data related to the wind noise reduction system 100. In some examples, the transceiver 195 sends the output voice signal 124 (see Figure 6 and Figure 7 ) to a peripheral device such as a smartphone to perform a phone call. The transceiver 195 can also receive data corresponding to settings of various aspects of the wind noise reduction system 100, such as the programmable filter weights of the beamformer 114, the equalizer 130, or the high-pass filter 132.

[0043] Figure 6 illustrates a functional block diagram of the wind noise reduction system 100 in the frequency domain form. The frequency domain wind noise reduction system 100 can be implemented to capture the spoken voice audio of the wearer W of the wearable audio device 10 (such as earbuds, see Figures 2 to 5 ) for use in a phone call or related applications. Thus, the frequency domain wind noise reduction system 100 generates an output voice signal 124. The output voice signal 124 (or an additional processed form of the output voice signal 124) can be wirelessly sent via the transceiver 195 (see Figure 5 ) to a peripheral device such as a smartphone and / or sent to the sound transducer 185 to provide sidetone to the wearer W of the wearable audio device 10.

[0044] As Figure 6 illustrated, the wind noise reduction system 100 includes three microphones disposed on the wearable audio device 10 to capture spoken voice audio, namely a first microphone 102 (e.g., as Figure 2 depicted), a second microphone 104 (e.g., as Figure 3 depicted), and a wind microphone 106 (e.g., as Figure 3 and Figure 4 depicted). As previously described, the wind microphone 106 is positioned on a portion of the wearable audio device 10 configured to sit on the outer ear C of the wearer W (see Figure 1 ), such that the wind microphone 106 faces the bottom surface F of the outer ear C (see Figure 1)。Therefore, the wind microphone 106 is shielded from wind noise, while the first microphone 102 and the second microphone 104 are exposed to wind noise because they are placed outside the outer ear C. In addition, the wind microphone 106 can also be used in a feedforward noise cancellation system.

[0045] Each of the microphones 102, 104, and 106 generates a time-domain electrical signal corresponding to the captured voice audio. The first microphone 102 generates a first microphone signal 108, the second microphone 104 generates a second microphone signal 110, and the wind microphone 106 generates a wind microphone signal 112. Then, the first microphone signal 108, the second microphone signal 110, and the third microphone signal 112 are converted to the frequency domain by a weighted, overlap, and add (WOLA) analysis filter bank.

[0046] Then, the first frequency-domain second microphone signal 208 and the second frequency-domain second microphone signal 210 are provided to the beamformer 114. As described above, the beamformer 114 is used to achieve directional audio capture using the first microphone 102 and the second microphone 104. The beamformer 114 generates a beamformed signal 216 using the first frequency-domain microphone signal 208 and the second frequency-domain microphone signal 210. In Figure 6 the example, the beamformer 114 is an MVDR beamformer. The algorithm employed by the MVDR beamformer minimizes the power of the noise captured by the first microphone 102 and the second microphone 104 while keeping the desired signal distortion-free. By doing so, in a diffuse noise environment such as a cafeteria-type background, the SNR performance of the MVDR beamformer can be better than that of other beamformers (such as a delay-and-sum beamformer). However, in a specific environment such as a strong wind environment, the MVDR beamformer can amplify noise instances at specific frequencies by up to 10 dB to 20 dB, thus having a negative impact on the SNR performance of the resulting beamformed signal.

[0047] The frequency-domain wind microphone signal 212 is provided to the equalizer 130. The equalizer 130 is configured to attenuate portions of the frequency-domain wind microphone signal 212 such that in a quiet windless environment, the energy level of the equalized wind microphone signal 254 is equal to the energy level of the beamformed signal 216 for more accurate wind detection. One or more filter weights of the equalizer 130 can be programmable and / or dynamic weights.

[0048] The wind noise reduction system 100 then determines the energy level of the beamformed signal 216 and the energy level of the equalized wind microphone signal 254. The first energy detector 138 receives the beamformed signal 216. The first energy detector 138 analyzes the beamformed signal 216 using a smoothed energy envelope analysis method to generate a beamformed energy level signal 242 that corresponds to the energy level of the beamformed signal 216. Similarly, the second energy detector 140 receives the equalized wind microphone signal 254. The second energy detector 140 analyzes the equalized wind microphone signal 254 using a smoothed energy envelope analysis method to generate a wind microphone energy level signal 244 that corresponds to the energy level of the equalized wind microphone signal 254.

[0049] The beamformed energy level signal 242 and the wind microphone energy level signal 244 are then provided to the comparator 118. The comparator 118 generates a comparison signal 220 that indicates whether the beamformed energy level signal 242 or the wind microphone energy level signal 244 is greater. In some examples, the comparison signal 220 may also indicate the degree of difference between the beamformed energy level signal 242 and the wind microphone energy level signal 244. In additional examples, the comparison signal 220 may be frequency-dependent, indicating the energy level that fluctuates with frequency. In yet additional examples, the comparator 118 may be made to focus on comparing the energy levels within a defined frequency range such as 200 Hz to 2 kHz. The frequency range of 200 Hz to 2 kHz is an example of a frequency range in which the wind microphone signal 112 may be superior to the beamformed signal 216 in windy conditions (in terms of characteristics such as SNR or noise floor level).

[0050] The equalized wind microphone signal 254 is then provided to the high-pass filter 132. The high-pass filter 132 is configured to remove or attenuate low-frequency noise in windy conditions. One or more filter weights of the high-pass filter 132 may be programmable and / or dynamic weights. It should be noted that, for accurate energy level comparison, the high-pass filter is not applied to the equalized wind microphone signal 254 received by the second energy detector 140. In addition, the high-pass filter is not applied to the beamformed signal 216 to preserve the low-frequency characteristics in non-windy conditions.

[0051] The comparison signal 220, the beamformed signal 216, and the filtered wind microphone signal 256 are provided to a voice mixer 122. The voice mixer 122 can act as a cross-fader to generate a frequency-domain output voice signal 224 based on the comparison signal 220 by switching between or blending the beamformed signal 216 and the filtered wind microphone signal 256. Since the comparison signal 220 will change based on the beamformed energy level signal 242 and the wind microphone energy level signal 244, the switching or blending setting of the voice mixer 122 will change accordingly. Thus, the voice mixer 122 can be regarded as a dynamic voice mixer.

[0052] In one example, the voice mixer 122 is configured to switch back and forth between the beamformed signal 216 and the filtered wind microphone signal 256 to generate the output voice signal 224. If the comparison signal 220 indicates that the energy level of the beamformed signal 216 is significantly higher than the energy level of the equalized wind microphone signal 254 (corresponding to a windy condition), the frequency-domain output voice signal 224 can correspond to the filtered wind microphone signal 256. If the comparison signal 220 indicates that the energy level of the beamformed signal 216 has dropped to be significantly lower than the energy level of the equalized wind microphone signal 254 (corresponding to a windless condition), the frequency-domain output voice signal 224 can switch to correspond to the beamformed signal 216. In some examples, such switching can be restricted to a frequency range where the performance of the wind microphone 106 (located in the outer ear C of the wearer W) is significantly better than that of the beamformer 114 in windy conditions. By dynamically switching back and forth, the voice mixer 122 adjusts the frequency-domain output voice signal 224 to use the beamformed signal 216 in windless conditions and the frequency-domain wind microphone signal 212 in windy conditions to improve performance over the entire applicable frequency range using only the beamformed signal 216 or the frequency-domain wind microphone signal 212.

[0053] In one example, such switching can be restricted to a defined frequency range. For example, if the energy level of the beamformed signal 216 is significantly higher than the energy level of the equalized wind microphone signal 254 (indicating a windy condition), the frequency-domain output signal 224 can be configured to correspond to the filtered wind microphone signal 256 below 2 kHz while corresponding to the beamformed signal 216 above 2 kHz, since wind noise has the most severe impact on the beamformed signal below 2 kHz.

[0054] In other examples, the frequency-domain output speech signal 224 is a blend of both the beamformed signal 216 and the filtered wind microphone signal 256, similar to a blended crossfade rather than switching between the two. If the comparison signal 220 indicates that the energy level of the beamformed signal 216 is higher than the energy level of the equalized wind microphone signal 254 by a ratio of 2 to 1 (indicating a windy condition), then the frequency-domain output speech signal 224 can be a blend of the beamformed signal 216 and the equalized wind microphone signal 254 at a ratio of 1 to 2. As in the previous example, this blend of the beamformed signal 216 and the filtered wind microphone signal 256 can be restricted to a defined frequency range within the frequency-domain output speech signal 224, such as below 2 kHz. In some examples, the ratio of the beamformed signal 216 to the filtered wind microphone signal 256 can vary with frequency.

[0055] Once the frequency-domain output speech signal 224 is generated, it can be provided to additional circuitry for further processing in the frequency domain. Alternatively, the frequency-domain output speech signal 224 can be converted to the time domain by the WOLA synthesis filter bank 150. The time-domain output speech signal 124 can then be further processed before being transmitted via the transceiver 195 to a peripheral device such as a smartphone for use in a phone call or related application.

[0056] In addition to reducing wind noise, the (time-domain) wind microphone signal 112 can also be used for feedforward noise cancellation to reduce the noise played back to the wearer W via the acoustic transducer 185. The wind microphone signal 112 can be provided to the feedforward noise cancellation controller 134. The feedforward noise cancellation controller 134 then generates an anti-noise signal 146 based on the wind microphone signal 112, and the anti-noise signal is provided to the acoustic transducer 185 to cancel the noise captured by the wind noise microphone 106, such as audible noise at the outer ear C of the wearer W.

[0057] Figure 7 Illustrates Figure 6 the time-domain variation. In Figure 7 wind noise cancellation and feedforward noise cancellation are performed to provide audible sidetone to the wearer W. Sidetone can be defined as audible feedback provided to the wearer W to confirm the proper operation of the wearable audio device 10. This audible feedback includes a small amount of the wearer W's speech. Hearing this audible feedback allows the wearer W to confirm that the microphones 102, 104 of the wearable audio device 10 are working properly, adjust their speaking volume to an appropriate level, and / or confirm that a voice call or other connection has been established. Using sidetone can also achieve additional beneficial effects for the wearer W, such as improving environmental audio transparency and enabling the wearer W to speak in a more natural voice. Since Figure 6The frequency domain transformation results in a certain degree of delay in the audio feedback, which may reduce the effectiveness of the audio feedback. Therefore, it is preferably to perform this sidetone processing in the time domain.

[0058] In Figure 7 , the first microphone signal 108 and the second microphone signal 110 are provided to the beamformer 114 as time domain signals. Similarly, the wind microphone signal 112 is provided to the equalizer 130 as a time domain signal. Thus, the signals generated by the beamformer 114 (beamformed signal 116), the first energy detector 138 and the second energy detector 140 (beamformed energy level signal 142 and wind microphone energy level signal 144), the equalizer 130 (equalized wind microphone signal 154), the high-pass filter 132 (filtered wind microphone signal 156), the comparator 118 (comparison signal 120), and the final voice mixer 122 (output voice signal 124) are also time domain signals similar to the frequency domain signals described in the reference Figure 6 . The time domain output voice signal 124 can be provided to additional circuitry for further processing in the time domain. In addition, the time domain output voice signal 124 can also be provided to the sidetone controller 136. The sidetone controller 136 processes the time domain output voice signal 124 into a sidetone signal 152 for playback to the wearer W via the acoustic transducer 185. When the acoustic transducer 185 plays back the sidetone signal 152, the noise near the outer ear C of the wearer W can be reduced by providing the anti-noise signal 146 to the acoustic transducer 185, as described in the reference Figure 6 .

[0059] Figure 8 is a flowchart of a method 900 for reducing wind noise. The method 900 includes generating 902 a beamformed signal via a beamformer based on a first microphone signal and a second microphone signal. The method 900 further includes generating 904 a comparison signal via a comparator based on the beamformed signal and a wind microphone signal. The method 900 further includes generating 906 an output voice signal via a dynamic voice mixer based on the beamformed signal, the wind microphone signal, and the comparison signal.

[0060] According to another example, the method 900 may further include optional steps among the following: (1) generating 908 a first microphone signal via a first microphone; (2) generating 910 a second microphone signal via a second microphone; and (3) generating 912 a wind microphone signal via a wind microphone disposed on a portion of the wearable audio device configured to be disposed in the outer ear of the wearer and facing the bottom surface of the outer ear.

[0061] All definitions as defined and used herein shall be understood to cover dictionary definitions, definitions in incorporated documents by reference, and / or the ordinary meaning of the defined terms.

[0062] Unless expressly stated to the contrary, as used herein in the specification and claims, the indefinite articles "a" and "an" shall be understood to mean "at least one".

[0063] As used herein in the specification and claims, the phrase "and / or" shall be understood to mean "either or both" of the elements so combined, i.e., elements that are present together in some cases and separate in other cases. Multiple elements listed with "and / or" shall be understood in the same way, i.e., "one or more" of the elements so combined. Other elements may optionally be present, whether related or unrelated to those specifically identified, in addition to the elements specifically identified by the "and / or" clause.

[0064] As used herein in the specification and claims, "or" shall be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" shall be understood to be inclusive, i.e., including at least one and more than one of the elements or list of elements, as well as any additional items not specifically listed. Only terms expressly stated to the contrary (such as "only one of... " or "exactly one of... " or "consisting of... " (when used in a claim)) shall refer to including exactly one of the elements or list of elements. In general, when followed by an exclusive term (such as "any one of", "one of... ", "only one of... " or "exactly one of... "), the term "or" as used herein shall be understood to indicate only an exclusive alternative (i.e., "one or the other but not both").

[0065] As used herein in the specification and claims, the phrase "at least one" (with respect to a list of one or more elements) shall be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one element of each element specifically listed in the list of elements, and not excluding any combination of the elements in the list. This definition also allows that elements other than those specifically identified within the list of elements referred to by the phrase "at least one" may optionally be present, whether related or unrelated to those specifically identified.

[0066] It should also be understood that, unless expressly stated to the contrary, in any method claimed herein that includes more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0067] In the claims and in the foregoing specification, all connecting phrases (such as "including", "comprising", "carrying", "having", "containing", "involving", "accommodating", "consisting of", etc.) shall be understood to be open-ended, i.e., meaning including but not limited to. Only the connecting phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed connecting phrases, respectively.

[0068] The above examples of the subject matter can be implemented in any of a variety of ways. For example, some aspects can be implemented using hardware, software, or a combination thereof. When any aspect is implemented at least partially in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single device or single computer or distributed among multiple devices / computers.

[0069] The present disclosure can be implemented as a system, method, and / or computer program product at any possible level of integration of technical details. The computer program product can include one (or more) computer-readable storage media having computer-readable program instructions thereon for causing a processor to implement aspects of the present disclosure.

[0070] A computer-readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. A computer-readable storage medium can be, by way of example and not limitation, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer-readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanically encoded device (such as a punched card or raised structure in a groove having instructions recorded thereon), and any suitable combination of the foregoing. As used herein, a computer-readable storage medium shall not be understood to be a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., an optical pulse through an optical fiber cable) or an electrical signal transmitted through a wire.

[0071] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a corresponding computing / processing device via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network), or to an external computer or external storage device. The network can include copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium within the corresponding computing / processing device.

[0072] The computer-readable program instructions for performing the operations of the present disclosure can be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state-setting data, configuration data for an integrated circuit system, or any combination thereof written in one or more programming languages, including: object-oriented programming languages such as Smalltalk, C++, etc.; and procedural programming languages such as the "C" programming language or similar programming languages. The computer-readable program instructions can be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer, partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., via the Internet using an Internet service provider). In some examples, an electronic circuit system, including, for example, a programmable logic circuit system, a field-programmable gate array (FPGA), or a programmable logic array (PLA), can execute the computer-readable program instructions to perform aspects of the present disclosure by using the state information of the computer-readable program instructions to personalize the electronic circuit system.

[0073] Aspects of the present disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to examples of the present disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0074] Computer-readable program instructions may be provided to a processor of a special purpose computer or other programmable data processing apparatus to produce a machine, such that the instructions executed via the processor of the computer or other programmable data processing apparatus create means for implementing the functions / acts specified in one or more boxes of the flowchart and / or block diagram. These computer-readable program instructions may also be stored in a computer-readable storage medium that can direct a computer, a programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer-readable storage medium having instructions stored therein comprises an article of manufacture including instructions implementing various aspects of the functions / acts specified in the flowchart and / or block diagram or boxes thereof.

[0075] The computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other devices to produce a computer-implemented process, such that the instructions executed on the computer, other programmable apparatus, or other devices implement the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0076] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various examples of the present disclosure. In this regard, each box in the flowchart or block diagram may represent a module, segment, or portion of instructions, which includes one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the boxes may occur out of the order noted in the figures. For example, two boxes shown in succession may, in fact, be executed substantially concurrently, or the boxes may sometimes be executed in the reverse order, depending upon the functionality involved. It should also be noted that each box of the block diagrams and / or flowchart illustrations, and combinations of boxes in the block diagrams and / or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

[0077] Other alternative implementations are within the scope of the following claims and other claims that the applicant may have.

[0078] While various examples have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other devices and / or structures for performing the functions and / or obtaining the results and / or one or more of the advantages described herein, and each such variation and / or modification is considered to be within the scope of the examples described herein. More generally, those skilled in the art will readily understand that all parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend upon one or more specific applications of the teachings of this invention. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation many equivalents to the specific examples described herein. Accordingly, it should be understood that the above examples are presented by way of illustration only and that the examples may be practiced otherwise than as specifically described and claimed within the scope of the appended claims and their equivalents. The examples of this disclosure relate to each and every individual feature, system, article, material, kit, and / or method described herein. Moreover, any combination of two or more such features, systems, articles, materials, kits, and / or methods is included within the scope of this disclosure if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent.

Claims

1. A wind noise reduction system, the wind noise reduction system comprises: a beamformer configured to generate a beamformed signal based on a first microphone signal and a second microphone signal; a comparator configured to generate a comparison signal based on the beamformed signal and a wind microphone signal; and a dynamic voice mixer configured to generate an output voice signal based on the beamformed signal, the wind microphone signal, and the comparison signal.

2. The wind noise reduction system according to claim 1, wherein, the beamformer is a minimum variance distortionless response (MVDR) beamformer.

3. The wind noise reduction system according to claim 1, wherein, the comparison signal is further based on a beamformed energy level of the beamformed signal and a wind energy level of the wind microphone signal.

4. The wind noise reduction system according to claim 1, wherein, the output voice signal is a blend of the beamformed signal and the wind microphone signal.

5. The wind noise reduction system according to claim 4, wherein, a ratio of the wind microphone signal to the beamformed signal in the output voice signal corresponds to the comparison signal.

6. The wind noise reduction system according to claim 5, wherein, the ratio of the wind microphone signal to the beamformed signal in the output voice signal is frequency-dependent.

7. The wind noise reduction system according to claim 1, wherein, the output voice signal corresponds to the wind microphone signal in a frequency range of 200 Hz to 2 kHz.

8. The wind noise reduction system according to claim 1, the wind noise reduction system further comprises: a first microphone corresponding to the first microphone signal; a second microphone corresponding to the second microphone signal; and a wind microphone corresponding to the wind microphone signal.

9. The wind noise reduction system according to claim 8, wherein, the wind microphone is arranged on a part of a wearable audio device configured to sit on the outer ear of a wearer.

10. The wind noise reduction system according to claim 8, wherein, the wind microphone faces the bottom surface of the outer ear of the wearer during use.

11. The wind noise reduction system according to claim 1, wherein, the first microphone signal, the second microphone signal, and the wind microphone signal are frequency domain signals.

12. The wind noise reduction system according to claim 1, wherein, the first microphone signal, the second microphone signal, and the wind microphone signal are time domain signals.

13. The wind noise reduction system according to claim 1, the wind noise reduction system further comprises an equalizer configured to filter the beamformed signal before the beamformed signal is received by the comparator and the dynamic voice mixer.

14. The wind noise reduction system according to claim 1, wherein the wind noise reduction system further comprises a high-pass filter configured to filter the beamformed signal before the beamformed signal is received by the dynamic voice mixer.

15. The wind noise reduction system according to claim 1, wherein the wind noise reduction system further comprises a feedforward noise cancellation controller for performing feedforward noise cancellation, wherein, the feedforward noise cancellation controller receives an input corresponding to the wind microphone signal.

16. A wearable audio device, the wearable audio device comprising: a first microphone configured to generate a first microphone signal; a second microphone configured to generate a second microphone signal; a wind microphone corresponding to a wind microphone signal; a beamformer configured to generate a beamformed signal based on the first microphone signal and the second microphone signal; a comparator configured to generate a comparison signal based on the beamformed signal and the wind microphone signal; and a dynamic voice mixer configured to generate an output voice signal based on the beamformed signal, the wind microphone signal, and the comparison signal.

17. The wearable audio device according to claim 16, wherein, the wind microphone is arranged on a part of the wearable audio device configured to be inserted into the outer ear of the wearer.

18. The wearable audio device according to claim 16, wherein, the wearable audio device is an earbud.

19. A method for reducing wind noise, the method comprising: generating a beamformed signal via a first beamformer based on a first microphone signal and a second microphone signal; generating a comparison signal via a comparator based on the beamformed signal and a wind microphone signal; and generating an output voice signal via a dynamic voice mixer based on the beamformed signal, the wind microphone signal, and the comparison signal.

20. The method according to claim 19, wherein the method further comprises: generating the first microphone signal via the first microphone; generating the second microphone signal via the second microphone; and generating the wind microphone signal via a wind microphone arranged on a part of the wearable audio device configured to be disposed in the outer ear of the wearer and facing the bottom surface of the outer ear.

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