Active noise reduction earbud

Abstract

To provide an active noise reduction earbud and method.SOLUTION: An in-ear earbud includes: a housing 42 comprising an outlet portion that defines a sound outlet 44, where the outlet portion is located in or near an external auditory meatus 92 of a user's ear 90; a first feedforward microphone 60 configured to generate a first input signal, and a first sound inlet opening 61 located in the housing and near the outlet portion and configured to conduct external sound to be sensed by the first feedforward microphone.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Application No. 17 / 362,625, filed June 29, 2021, the entire disclosure of which is incorporated herein by reference for all purposes. [Background technology]

[0002] The present disclosure relates to active noise reduction (ANR) audio devices carried on or in a user's ears.

[0003] ANR audio devices carried on or in a user's ear include earphones and headphones configured with sound outlets located in or very close to the user's external auditory canal (i.e., external ear canal). ANR typically involves using one or more feedforward microphones to detect external sounds and a feedback microphone to detect internal sounds. Audio drivers are driven to reduce or cancel sensed external sounds before they reach the user's eardrum. Summary of the Invention [Means for solving the problem]

[0004] Aspects and embodiments are directed to earphones whose coherence is improved by positioning a feedforward microphone to sense noise at or very close to the eartip. At higher frequencies, the main noise path to a user's eardrum is typically through the eartip and body tissue. A feedforward microphone close to the eartip, which is naturally close to the tissue near the ear canal, is positioned to sense noise within this main noise path, resulting in high coherence. This sensed noise can then be canceled by an ANR system.

[0005] All embodiments and features mentioned below can be combined in any technically possible manner.

[0006] In one aspect, an active noise reduction (ANR) earphone includes a housing with an exit portion defining a sound exit, the exit portion configured to be positioned in or adjacent to the ear canal of a user's ear. There is a first feedforward microphone configured to generate a first input signal, and a first sound entrance opening within the housing and configured to transmit external sounds sensed by the first feedforward microphone. The first sound entrance opening is adjacent to the exit portion.

[0007] Some embodiments include one of the above and / or below features, or any combination thereof. In one embodiment, when the exit portion is located in or adjacent to the ear canal of the user's ear, the first sound entrance opening is within the concha of the user's ear. In one embodiment, when the exit portion is located in or adjacent to the ear canal of the user's ear, the first sound entrance opening directly faces the pinna of the user's ear.

[0008] Some embodiments include one of the above and / or below features, or any combination thereof. In some embodiments, the ANR earphone further includes a second feedforward microphone configured to generate a second input signal and a second sound inlet opening in the housing configured to transmit external sound sensed by the second feedforward microphone. In one embodiment, the ANR earphone further includes a first acoustic port in the housing in fluid communication with the ear canal, at least one of the first sound inlet opening and the second sound inlet opening being proximate to the first acoustic port. In one embodiment, the ANR earphone further includes a second acoustic port in the housing in fluid communication with the ear canal, the first sound inlet opening being proximate to the first acoustic port, and the second sound inlet opening being proximate to the second acoustic port. In one embodiment, the coherence of the ANR earphone determined from only the first input signal in a frequency range is greater than the coherence in a frequency range determined from only the second input signal. In one embodiment, the frequency range is greater than 3 kHz.

[0009] Some embodiments include one of the above and / or below features, or any combination thereof. In some embodiments, the outlet portion comprises a flexible ear tip defining a sound outlet. In one embodiment, the first sound entrance opening is adjacent to the ear tip. In one embodiment, the first sound entrance opening is within the concha of the user's ear when the ear tip is positioned in or adjacent to the ear canal of the user's ear.

[0010] In another aspect, a method includes receiving a first input signal generated by a first feedforward microphone associated with an active noise reduction (ANR) earphone having a housing with an exit portion defining a sound exit, the exit portion configured to be located in or adjacent to an ear canal of a user's ear. The first feedforward microphone is configured to sense external sound transmitted through a first sound inlet opening in the housing adjacent to the exit portion. The first input signal is processed using a first filter to generate a first output signal for an acoustic transducer of the ANR earphone.

[0011] Some embodiments include one of the above and / or below features, or any combination thereof. In one embodiment, when the exit portion is located in or adjacent to the ear canal of the user's ear, the first sound entrance opening is within the concha of the user's ear. In one embodiment, when the exit portion is located in or adjacent to the ear canal of the user's ear, the first sound entrance opening directly faces the pinna of the user's ear.

[0012] Some embodiments include one of the above and / or the following features, or any combination thereof. In some embodiments, the ANR earphone further comprises a second feedforward microphone configured to generate a second input signal and a second sound inlet opening in the housing configured to transmit external sound sensed by the second feedforward microphone. In one embodiment, the ANR earphone further comprises a first acoustic port in the housing in fluid communication with the ear canal, at least one of the first sound inlet opening and the second sound inlet opening being proximate to the first acoustic port. In one embodiment, the ANR earphone further comprises a second acoustic port in the housing in fluid communication with the ear canal, the first sound inlet opening being proximate to the first acoustic port, and the second sound inlet opening being proximate to the second acoustic port. In one embodiment, the coherence of the ANR earphone determined from only the first input signal in a frequency range is greater than the coherence in a frequency range determined from only the second input signal. In one embodiment, the frequency range is greater than 3 kHz.

[0013] Some embodiments include one of the above and / or below features, or any combination thereof. In some embodiments, the outlet portion comprises a flexible ear tip defining a sound outlet. In one embodiment, the first sound entrance opening is adjacent to the ear tip. In one embodiment, the first sound entrance opening is within the concha of the user's ear when the ear tip is positioned in or adjacent to the ear canal of the user's ear.

[0014] Various aspects of at least one example are discussed below with reference to the accompanying drawings, which are not intended to be drawn to scale. These drawings are included to provide illustration and a further understanding of the various aspects and examples, and are incorporated into and constitute a part of this specification, but are not intended as a definition of the limits of the invention. In the drawings, identical or nearly identical components shown in various figures may be labeled with like letters or numerals. For clarity, not every component may be labeled in every figure. [Brief explanation of the drawings]

[0015] [Figure 1A] 1 is a schematic cross-sectional view of an in-ear earphone. [Figure 1B] 1 is a schematic cross-sectional view of an in-ear earphone in use position within a user's ear. [Figure 2] FIG. 1 is a functional block diagram of an embodiment of an ANR earphone with multiple feedforward microphones. [Figure 3] FIG. 1 is a schematic three-dimensional view of an earphone. [Figure 4] Comparison of coherence between ANR earphones and different microphone configurations. [Figure 5] Comparison of coherence between ANR earphones and different microphone configurations. [Figure 6] Comparison of coherence between ANR earphones and different microphone configurations. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present disclosure relates to wearable audio devices. Some non-limiting examples of the present disclosure describe wearable audio devices of a type known as in-ear headphones or earphones. Earphones generally include an electro-acoustic transducer or audio driver for generating sound and are configured to deliver sound directly to or very near the user's ear canal. Earphones can be wireless or wired. In non-limiting examples described herein, the earphones include one or more feedforward microphones that sense external sounds outside the housing. The feedforward microphones can be used for features such as active noise reduction (ANR) and transparency mode operation, in which external sounds are reproduced for the user by the electro-acoustic transducer. Other aspects of earphones not included in this disclosure are not shown or described. ANR earphones and headphones typically also use internal feedback microphones, as known in the art.

[0017] Some embodiments of the present disclosure also describe a type of wearable audio device known as an open-type audio device. Open-type audio devices have one or more electro-acoustic transducers (i.e., audio drivers) located away from the ear canal opening. Open-type audio devices also include one or more external microphones that can be used to pick up the user's voice and / or for ANR and / or for transparency mode operation.

[0018] Headphones typically refer to devices worn around, on, or in the ear and radiate acoustic energy directly or indirectly into the ear canal. Headphones are sometimes referred to as earphones, earpieces, headsets, mini-ears, or sports headphones and can be wired or wireless. Headphones contain drivers that convert audio signals into acoustic energy. The drivers may or may not be housed in earcups or housings configured to rest on the head or ear or to be inserted directly into the user's ear canal. A headphone may be a single, standalone unit, one for each ear, or one of a pair of headphones (each containing at least one acoustic driver). One headphone may be mechanically connected to the other headphone, for example, by a headband and / or by leads that carry audio signals to the acoustic drivers in the headphones. Headphones may include components that wirelessly receive audio signals. Headphones may also include components of an ANR system, which may include an internal microphone within the headphone housing and one or more external microphones that pick up sound outside the housing. The headphones may also include other features, such as an additional microphone for an ANR system, or one or more microphones used to pick up the user's voice.

[0019] Open-type audio devices include, but are not limited to, off-ear headphones, i.e., devices having one or more electro-acoustic transducers that are coupled to the head or ear (typically by a support structure) but do not occlude the ear canal opening. In some examples, open-type audio devices are typically off-ear headphones configured to deliver sound to one or both ears of the wearer, without the presence of ear cups and ear buds. Wearable audio systems contemplated herein may include a variety of devices that include over-the-ear hooks or anchors, one non-limiting example of which includes audio glasses.

[0020] One or more of the devices, systems, and methods described herein can be used in various embodiments and combinations in a wide variety of wearable audio devices or systems, including wearable audio devices of various form factors, including, but not limited to, in-ear devices, earphones, and hearing aids. Unless otherwise specified, a wearable audio device or system includes headphones and various other types of wearable audio devices, such as head- or ear-worn acoustic devices that include one or more acoustic transducers for receiving and / or generating sound and have a sound outlet in or near the ear canal.

[0021] While specific implementations of wearable audio devices primarily serving the purpose of acoustically outputting audio have been presented in some detail, it should be noted that the presentation of such specific implementations is intended to facilitate understanding through the provision of examples and should not be construed as limiting either the scope of the disclosure or the scope covered by the claims.

[0022] In some embodiments, a wearable audio device includes an electroacoustic transducer configured to generate sound for a user, a housing that holds the transducer and has a sound outlet, and at least one feedforward microphone configured to detect sound outside the housing and output a microphone signal. The processor system is programmed to achieve ANR using external feedforward microphone(s) and an internal feedback microphone, as known in the art. The sound inlet opening leading to the feedforward microphone is located near the device's sound outlet and thus near the ear canal, and the feedforward microphone senses external noise that reaches the ear canal through the ear tip of an earphone and body tissue. Thus, the ANR system can reduce or cancel this external noise.

[0023] In ANR earphones, the effectiveness of ANR using a feedforward microphone can be estimated by coherence. Coherence is the fraction of the power of the output signal at any given frequency that can theoretically be canceled by a linear control system using input from the feedforward microphone. Coherence is therefore a value between 0 and 1. The greater the coherence, the more effective the noise cancellation potential. The coherence limit is 1 - coherence, and therefore the fraction left after cancellation has been performed.

[0024] In earphones, noise can reach the user's ear through various paths, including through the acoustic port, through the ear tip, and through body tissue. If the diffuse noise is not sensed by the microphone, it cannot be actively canceled by the ANR system. Therefore, ANR is more effective (i.e., has greater coherence) if a feedforward microphone is located at or near any position on the earphone that is in or adjacent to the path of the diffuse noise. In some embodiments, ANR effectiveness is increased by the use of multiple feedforward microphones in the concha. In some embodiments, such feedback insertion gain can be combined with passive insertion loss.

[0025] Wireless earphones typically include a housing that houses the audio driver, electronics, antenna, battery, and battery charging contacts. The required size of the housing may require that at least a portion of the housing be located farther from the ear canal, for example, outside the concha or even outside the outer ear (also known as the pinna or pinna). Therefore, a feedforward microphone located within the housing is necessarily spaced away from the ear canal and is therefore ineffective at detecting noise that enters through the ear tip and body tissue. Consequently, the ANR coherence in these earphones is lower than desired. An external microphone can also be used to preview noise and overcome the delay of the acoustic path from the driver to the ear as well as the delay of the electronics. A microphone farther from the ear may have a better preview from at least some directions. Therefore, it may be useful to have one microphone near the ear canal and one microphone further outside.

[0026] The coherence of earphones can be improved by positioning the feedforward microphone so that it senses noise in or very close to the dominant noise path. The dominant noise path is frequency-dependent. One noise path can be through the ear tip and adjacent body tissue near the ear canal. The feedforward microphone near the ear tip, which is naturally close to the tissue near the ear canal, is positioned to sense noise within this dominant noise path. This sensed noise can then be canceled by the ANR system, resulting in greater coherence for the frequency range of interest.

[0027] In some embodiments, this feedforward microphone is configured to be located in the concha, with the earbud housing overlying the feedforward microphone when the earbud is inserted in the ear. Thus, locating the feedforward microphone in the concha also allows the microphone to be less affected by wind, potentially resulting in less problematic wind noise compared to a microphone located on the exterior-facing side of the earphone, where the housing does not overlie and therefore shield the microphone from wind. This can be important for both ANR and transparency mode operation.

[0028] FIG. 1A is a schematic cross-sectional view of an in-ear earphone 10, with components not drawn to scale and only some components relevant to the present disclosure. The earphone is a non-limiting example of a wearable audio device and can be wired or wireless. The earphone 10 includes a body or housing 12 that houses the active components of the earphone. A sound outlet 14 is at the end of an eartip 16, which is supported by a housing outlet portion 18. As known in the art, the eartip 16 can be configured for insertion into the entrance of the ear canal. An audio driver 20 directs front acoustic radiation into a front acoustic cavity / chamber 22 and rear acoustic radiation into a rear acoustic cavity / chamber 24. The front and rear sounds are out of phase. The rear chamber 24 has one or more ports configured to allow sound to escape to the external environment. In this non-limiting example, rear chamber 24 has one or both of first port 25 (which in one example is a resistance port comprising an acoustic mesh (not shown) covering a shallow opening open to the external environment) and second port 26 (which in one example is a mass port comprising a long tube open to the external environment). Any one or more of the rear ports can have any desired length and configuration. In some examples, the openings of ports 25 and 26 are both in side 13 of housing 12 that faces the pinna when ear tip 16 is inserted into the ear canal.

[0029] The ANR system includes one or more feedforward microphones, each configured to sense external sounds, and one or more internal microphones, each configured to sense internal sounds. In this non-limiting example, the ANR system uses one internal microphone and two external microphones, although there may be only one, two, or more external feedforward microphones. Internal microphone 28 is configured to sense sounds entering the user's ear canal, which can be achieved by placing the microphone within front cavity 22 or between the cavity and earphone sound outlet 14. External feedforward microphones 30 and 32 are located on different portions of housing 12 and are therefore configured to sense noise that may enter the ear through different noise paths. For example, microphone 30 is close to sound outlet 14 and therefore can sense noise that enters through ear tip 16 and surrounding body tissue. Microphone 30 is also close to port openings 25 and 26 and therefore can sense noise that enters through these openings. Generally, the microphones are omnidirectional devices located just below the surface of the housing with an overlying cavity open to the external environment so that external sound can reach the microphone. The quantity, placement, and function of the external feedforward microphones are described in more detail elsewhere herein.

[0030] 1B is a cross-sectional view of a similar earphone 40 in place within an ear 90, with the eartip 46 contacting the ear at or very near the entrance to the ear canal 92. When the eartip 46 is received within the ear canal, the earphone housing 42 is configured to reside at least partially within the outer ear 91, meaning that at least a portion of the housing 42 is between the outer extent of the crus helix 98 and the entrance to the ear canal 92. In this non-limiting example, most, if not all, of the housing 42 is configured to reside within the outer ear 91, including the housing's inner surface 45 (facing / directly facing the outer ear 91 so that the housing is not between surface 45 and the outer ear 91), the housing side surface 47, and possibly some or all of the housing's outer surface 43, which faces opposite the inner surface 45 and faces directly toward the external environment, away from the head. A feedforward microphone 60 is located within the housing 42. A sound inlet opening 61 in the inner surface 45 of the housing 42 is configured to transmit external sounds to be sensed by the microphone 60. A second feedforward microphone 74 is located inside the housing 42. A sound inlet opening 72 in the exterior surface 43 of the housing 42 is configured to transmit external sounds to be sensed by the microphone 74.

[0031] As described above, the coherence of an earphone ANR system is at least partially improved when there is an ANR feedforward microphone positioned to sense noise that would otherwise reach the user's eardrum unless reduced or canceled by the ANR system. The ANR system is configured to inject an opposing signal, resulting in destructive interference of the noise. The primary noise path in an earphone is typically through the acoustic port, through the ear tip, and through body tissue adjacent to the ear canal. If one or more feedforward microphones are configured to sense external sounds along these noise paths, the noise can be canceled, resulting in greater coherence.

[0032] The earphone 40 includes an audio driver 50 that generates sound pressure in both a front cavity acoustic volume 52 and a rear cavity acoustic volume 54. An optional pressure-equalizing vent with an opening 76 between the front and rear volumes and covered by an acoustic mesh 78 fluidly interconnects the front and rear volumes. There may be one or more acoustic ports for the rear volume 54. In this non-limiting example, there is a rear resistance port with an acoustic mesh 67 over a shallow opening 65 in the housing interior surface 45 and open to the external environment, as well as a rear mass port 56 with a long tube also open to the external environment, also open at the housing interior surface 45. Both the resistance port and the mass port have openings in the housing that are pathways for external noise to pass through the pressure-equalizing port and reach the eardrum. Note that the port openings may be located elsewhere in the housing. By positioning the feedforward microphone 60 so that its sound inlet opening 61 is proximate to both the resistance port and the mass port, the signal generated by the microphone 60 can sense noise entering through the resistance port and the mass port, thus increasing the coherence of the ANR. Also, because the sound inlet opening 61 of the microphone 60 is proximate to the ear tip 46 and body tissue proximate to the ear canal, the signal generated by the microphone 60 can sense noise entering through the ear tip 46 and body tissue proximate to the ear canal, thus increasing the coherence of the ANR. In some embodiments, a feedforward microphone for the ANR system is located near or adjacent to each sound inlet opening (e.g., port) through which external sound can reach the eardrum. In this way, noise paths to the eardrum can be sensed and therefore canceled.

[0033] The sound inlet 61 is located in the concha 94 of the ear 90. While ear anatomy varies considerably from person to person, the concha is generally a concave surface on the median surface of the ear's pinna, separated by a protuberance (the crus helicalis) into a superior concha chamber and an inferior concha chamber that connect to the ear canal. By positioning the sound inlet 61 in the concha 94, preferably in the concha chamber where most or all of the ear tip 46 is located, noise entering through the ear tip can be sensed and reduced or canceled by the ANR function. Also, by positioning the sound inlet 61 of the microphone 60 in the concha chamber directly adjacent to the ear canal, the microphone 60 senses noise entering the ear through the tissue surrounding the ear canal, and therefore the ANR function can reduce or cancel this noise.

[0034] In earphone 40, second feedforward microphone 74 (having sound inlet opening 72 in outer housing surface 43) is configured to sense noise in the environment earlier than microphone 60, so the ANR system has more time to react to this noise signal before it reaches the ear and can therefore be more effective at canceling noise. Microphone 74 is also positioned to sense the user's voice, for example, for use in communications (e.g., phone calls and voice-activated devices). Internal ANR feedback microphone 58 is configured to sense sound entering the user's ear canal, which can be achieved by positioning the microphone within front cavity 52 or between the cavity and sound outlet 44.

[0035] A functional aspect of an ANR earphone 100 having multiple feedforward microphones 100 is illustrated in FIG. 2. Signals from each feedforward microphone (feedforward microphone 1 (104) and feedforward microphone 2 (106)) and signals from the feedback microphone(s) (feedback microphone 108) are input to a controller 102, which in some embodiments comprises a vector of multiple controllers. In some embodiments, the controller 102 comprises one filter associated with each feedforward microphone. The controller 102 provides output signals for an audio driver 110, which in part achieves sound pressure to reduce noise as part of the ANR function. ANR audio devices with one or more external feedforward microphones and one or more internal feedback microphones are known in the art, and therefore aspects such as the design of one or more ANR controllers, the filters applied by the controllers, and the customization of ANR associated with the earpiece or earphone used in the acoustic device will not be further described herein. Such embodiments are described in US Pat. Nos. 10,665,220 and 10,937,410, the entire disclosures of which are incorporated herein by reference for all purposes.

[0036] FIG. 3 is a schematic, partial, three-dimensional view of earphone 120, in which housing 121 includes main portion 122, intermediate portion 128, and exit portion 126. Ear tip 129 (configured to be inserted into the ear canal) is coupled to exit portion 126 and defines earphone sound exit 124. Several possible external feedforward and / or communication microphones are indicated by small squares, including locations 132 configured to be located within the concha, very close to the ear canal. Dashed line 150 indicates the approximate outer boundary of the concha. Given that the microphone must be located below the surface of the housing and that wiring must extend between the microphone and at least the controller (not shown, typically located within main housing portion 122), it may be physically difficult to position the microphone very close to the earphone exit. Housing intermediate portion 128 leads from main portion 122 to exit portion 126, and is therefore closer to the location of the controller, but at the same time, is also close to ear tip 129. Thus, portion 128 can accommodate microphone(s) (e.g., microphones 134 and 136) more easily than portion 126, but is still closer to ear tip 129 and the ear canal opening and, therefore, still within or very close to the noise path through the tissue proximate to the ear tip and ear canal. Either or both of microphones 134 and 136 can be used as a feedforward microphone for ANR functionality. In some embodiments, one of microphones 134 and 136 is used as a feedforward microphone and may also be used for sound pickup. In some embodiments, main housing 122 includes one or more of microphones 138, 140, 142, and 144. In one embodiment, one of these microphones can be collocated with one of microphones 134 and 136 for sound pickup, as known in the art.

[0037] 4 compares the coherence limits (plotted as insertion gain) of the ANR earphone 120 of FIG. 3 when a microphone on an outer portion of the main housing portion 122 (e.g., microphone 142 or 144) is used as the feedforward microphone (plot lines 162 and 164) with a microphone on the intermediate housing portion 128 (e.g., microphone 134 or 136) is used as the feedforward microphone (plot line 166). As can be seen, from about 200 Hz to about 6 kHz, the coherence with microphone 134 or 136 located on the concha, close to the ear tip and ear canal opening, is about 5 dB or more better than the coherence with a microphone on the main housing portion not located on the concha and further from the ear tip and ear canal opening. In some embodiments, this frequency range where coherence is improved encompasses the range where the main noise path is through the ear tip and surrounding body tissue.

[0038] 5 compares the coherence limits (plotted as insertion gain) of the ANR earphone 120 of FIG. 3 with those when two separate microphones are used in the ANR function instead of just one (although a comparison with a single microphone is included to illustrate some advantages of using two feedforward microphones for ANR). Plot line 174 is for a single microphone (e.g., microphone 142 or 144) on the outside of main housing portion 122 as the feedforward microphone. Plot line 176 is for two feedforward microphones, one on intermediate housing portion 128 (e.g., microphone 134 or 136) and the other on the outside of main housing portion 122 (e.g., microphone 142 or 144). Plot line 180 is for two feedforward microphones, one on the intermediate housing portion 128 (e.g., microphone 134 or 136) and the other on the inside of the main housing portion 122 closest to the intermediate portion 128 (e.g., microphone 138 or 140). Figure 5 establishes that adding a second feedforward microphone on the intermediate portion 128 helps achieve better coherence than using a single microphone on the main housing portion.

[0039] 6 compares the single and multiple coherence limits (plotted as insertion gain) of the ANR earphone 120 of FIG. 3 using either one or two separate microphones on the mid-housing portion 128 in the ANR function. Plot line 192 is for a single microphone on the mid-housing portion 128 (e.g., one of microphones 134 or 136) as the feedforward microphone. Plot line 194 is also for a single microphone on the mid-housing portion 128 (e.g., the other of microphones 134 or 136) as the feedforward microphone. Plot line 196 is for two feedforward microphones (e.g., microphones 134 and 136) both on the mid-housing portion 128. Thus, the use of multiple microphones can result in greater reduction of diffuse noise.

[0040] The system, method, and device embodiments described herein are not limited in their application to the details of construction and arrangement of components set forth in the following description or illustrated in the accompanying drawings. The systems, methods, and devices may be implemented in other embodiments and may be practiced or carried out in various ways. Specific embodiments are provided herein for illustrative purposes only and are not intended to be limiting. In particular, functions, components, elements, and features discussed in connection with any one or more embodiments are not intended to be excluded from a similar role in any other embodiments.

[0041] Examples disclosed herein may be combined with other examples in any manner consistent with at least one of the principles disclosed herein, and further, references to "an example," "some examples," "an alternate example," "various examples," "one example," etc. are not necessarily mutually exclusive and are intended to indicate that a particular feature, structure, or characteristic described may be included in at least one example. Appearances of such terms herein do not necessarily all refer to the same example.

[0042] Additionally, the phraseology and terminology used herein are for descriptive purposes only and should not be considered limiting. Any reference herein to computer program product, system, and method examples, components, elements, acts, or functions in the singular may also encompass embodiments that include the plural, and any reference herein to any example, component, element, act, or function in the plural may also encompass examples that include only the singular. Thus, singular or plural references are not intended to limit the disclosed systems or methods, their components, acts, or elements. The use herein of "including," "comprising," "having," "containing," "involving," and variations thereof, is meant to encompass the items listed below and their equivalents, as well as other items. References to "or" may be construed as inclusive, such that all terms described with "or" refer to either the singular, the plural, and all terms of the described term.

[0043] Some elements in the figures are shown and described as individual elements in block diagrams. These elements may be implemented as one or more of analog or digital circuitry. Alternatively, or additionally, these elements may be implemented by one or more microprocessors executing software instructions. The software instructions may include digital signal processing instructions. Operations may be performed by analog circuitry or by a microprocessor executing software that performs the equivalent of the analog operations. Signal lines may be implemented as individual analog or digital signal lines, as individual digital signal lines with appropriate signal processing capable of processing the separate signals, and / or as elements of a wireless communication system.

[0044] When a process is depicted or suggested by a block diagram, the steps may be performed by one element or by multiple elements. These steps may be performed together or at different times. Elements performing activities may be physically the same, or may be in close proximity to each other, or may be physically separate. One element may perform more activities than one block. Audio signals may be coded or uncoded and may be transmitted in either digital or analog form. Conventional audio signal processing equipment and operations may be omitted from the drawings.

[0045] The example systems and methods described herein include computer components and computer-implemented steps that will be apparent to those skilled in the art. For example, those skilled in the art should understand that the computer-implemented steps may be stored as computer-executable instructions on a computer-readable medium, such as, for example, flash ROM, non-volatile ROM, and RAM. Furthermore, those skilled in the art should understand that the computer-executable instructions may be executed on a variety of processors, such as, for example, microprocessors, digital signal processors, gate arrays, etc. For ease of description, not all steps or elements of the systems and methods are described herein as part of a computer system, but those skilled in the art will recognize that each step or element may have a corresponding computer system or software component. Accordingly, such computer systems and / or software components are enabled by the description of their corresponding steps or elements (i.e., their functionality) and are within the scope of the present disclosure.

[0046] The functions, methods, and / or components of the methods and systems disclosed herein according to various aspects and embodiments may be implemented or performed with digital signal processors (DSPs) and / or other circuitry, analog or digital, suitable for performing signal processing and other functions according to the aspects and embodiments disclosed herein. Additionally or alternatively, microprocessors, logic controllers, logic circuits, field programmable gate array(s) (FPGAs), application specific integrated circuits (ASICs), general purpose computing processor(s), microcontroller(s), etc., or any combination thereof, may be suitable and, for any particular implementation, may include analog or digital circuit components and / or other components.

[0047] The functions and components disclosed herein may operate in the digital domain, the analog domain, or a combination of the two, and particular embodiments include analog-to-digital converters (ADCs) and / or digital-to-analog converter(s) (DACs) where appropriate, despite the lack of illustration of ADCs or DACs in the various figures. Furthermore, the functions and components disclosed herein may operate in the time domain, the frequency domain, or a combination of the two, and particular embodiments include various forms of Fourier or similar analysis, synthesis, and / or transforms to accommodate processing in the various domains.

[0048] Any suitable hardware and / or software, including firmware, etc., may be configured to perform or implement components of the aspects and embodiments disclosed herein, and various implementations of the aspects and embodiments may include components and / or functionality in addition to those disclosed. Various implementations may include stored instructions in digital signal processors and / or other circuitry to enable the circuitry to, at least in part, perform the functions described herein.

[0049] Having described several aspects of at least one embodiment, it will be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure and be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only, with the scope of the invention to be determined from proper construction of the appended claims and their equivalents. [Explanation of symbols]

[0050] 10 In-ear earphones 12 Housing 13 Side 14 Earphone sound outlet 16 ear tips 18 Housing outlet 20 Audio Driver 22 Anterior cavity 24 Rear chamber 25 First Port 26 Second Port 28 Internal Microphone 30 and 32 External Feedforward Microphones 40 Earphones 42 Housing 43 Housing outer surface 44 Sound exit 45 Housing inner surface 46 ear tips 47 Housing side 50 Audio Driver 52 Anterior cavity 54 Posterior volume 56 Rear mass port 58 Internal ANR Feedback Microphone 60 Feedforward Microphone 61 Sound Entrance 65 Opening 67 Acoustic Mesh 72 Sound inlet opening 74 Second Feedforward Microphone 76 Opening 78 Acoustic Mesh 90 ears 91 External ear 92 External auditory canal 94 Turbinate 98 Earring leg 100 Functional aspects 102 Controller 104 Feedforward Microphone 108 Feedback Microphone 110 Audio Driver 120 ANR earphones 121 Housing 122 Main housing part 124 Earphone sound outlet 126 Exit part 128 Intermediate housing part 129 Eartips 132 microphone configuration positions 134, 136, 138, 140, 142, 144 microphones

Claims

1. An active noise reduction (ANR) earphone, a housing including an outlet portion defining a sound outlet, the outlet portion configured to be positioned within or adjacent to an ear canal of a user's ear; a first feedforward microphone configured to generate a first input signal; a first sound inlet opening within the housing and configured to transmit external sound sensed by the first feedforward microphone, the first sound inlet opening being proximate to the exit portion.

2. 2. The ANR earphone of claim 1, wherein the first sound entrance opening is within the concha of the user's ear when the exit portion is located within or adjacent to the ear canal of the user's ear.

3. 2. The ANR earphone of claim 1, wherein when the exit portion is located in or adjacent to the ear canal of the user's ear, the first sound entrance opening directly faces the pinna of the user's ear.

4. 10. The ANR earphone of claim 1, further comprising: a second feedforward microphone configured to generate a second input signal; and a second sound inlet opening within the housing configured to transmit external sound sensed by the second feedforward microphone.

5. 5. The ANR earphone of claim 4, further comprising a first acoustic port in the housing in fluid communication with the ear canal, wherein at least one of the first sound inlet opening and the second sound inlet opening is adjacent to the first acoustic port.

6. 6. The ANR earphone of claim 5, further comprising a second acoustic port in the housing in fluid communication with the ear canal, the first sound entrance opening being adjacent to the first acoustic port and the second sound entrance opening being adjacent to the second acoustic port.

7. 5. The ANR earphone of claim 4, wherein the coherence of the ANR earphone in a frequency range determined from only the first input signal is greater than the coherence in the frequency range determined from only the second input signal.

8. The ANR earphone of claim 7 , wherein the frequency range is greater than 3 kHz.

9. The ANR earphone of claim 1 , wherein the exit portion comprises a flexible ear tip that defines the sound exit.

10. The ANR earphone of claim 9 , wherein the first sound inlet opening is adjacent to the ear tip.

11. 11. The ANR earphone of claim 10, wherein the first sound entrance opening is within the concha of the user's ear when the ear tip is positioned in or adjacent to the ear canal of the user's ear.

12. 1. A method comprising: receiving a first input signal generated by a first feedforward microphone associated with an active noise reduction (ANR) earphone having a housing with an exit portion defining a sound exit, the exit portion configured to be located in or proximate to an ear canal of a user's ear, the first feedforward microphone configured to sense external sound transmitted through a first sound entrance opening in the housing proximate to the exit portion; and processing the first input signal using a first filter to generate a first output signal for an acoustic transducer of the ANR earphone.

13. 13. The method of claim 12, wherein the first sound entrance opening is within the concha of the user's ear when the exit portion is located within or adjacent to the ear canal of the user's ear.

14. 13. The method of claim 12, wherein when the exit portion is located in or adjacent to the ear canal of the user's ear, the first sound entrance opening faces directly toward the pinna of the user's ear.

15. 13. The method of claim 12, wherein the ANR earphone further comprises: a second feedforward microphone configured to generate a second input signal; and a second sound inlet opening in the housing configured to transmit external sound sensed by the second feedforward microphone.

16. 16. The method of claim 15, wherein the ANR earphone further comprises a first acoustic port in the housing in fluid communication with the ear canal, and at least one of the first sound entrance opening and the second sound entrance opening is proximate to the first acoustic port.

17. 17. The method of claim 16, wherein the ANR earphone further comprises a second acoustic port in the housing in fluid communication with the ear canal, the first sound entrance opening being proximate to the first acoustic port and the second sound entrance opening being proximate to the second acoustic port.

18. 16. The method of claim 15, wherein a coherence of the ANR earphone in a frequency range determined from only the first input signal is greater than the coherence in the frequency range determined from only the second input signal.

19. 20. The method of claim 18, wherein the frequency range is greater than 3 kHz.

20. The method of claim 12 , wherein the exit portion comprises a flexible ear tip that defines the sound exit.

21. 21. The method of claim 20, wherein the first sound inlet opening is adjacent the ear tip.

22. 22. The method of claim 21, wherein the first sound entrance opening is within the concha of the user's ear when the ear tip is located in or adjacent to the ear canal of the user's ear.

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