Patent Description:
Earbuds for use with consumer electronic devices, for example, audio players and wireless communications devices (e.g., cell phones and personal data assistant devices incorporating cell phone capabilities) may be connected to an electronic device via a wired connection or wirelessly. Consumers generally prefer earbuds that are small and lightweight and comfortable to wear. Small and lightweight earbuds, however, can accommodate batteries of only a limited size and thus, a limited capacity. If a user accidentally powers on and sends audio to be played to an earbud while it is not in the ear of the user, or removes the earbud from the ear without first terminating rendering of audio by the earbud, battery life of the earbud may be unintentionally wasted. Further, it may be desirable to automatically control aspects of audio playback when the earbuds are placed in a user's ear or taken out of a user's ear.

Document <CIT> discloses pressure sensing earbuds that include one or more pressure sensors to determine the size and shape of a user's ear. The pressure signals can be relayed back to a processor, which may use them to dynamically optimize the volume levels delivered for frequencies over the audible range for a particular user.

Document <CIT> discloses ear buds that communicate wirelessly with an electronic device. To determine the current status of the ear buds and thereby take suitable action in controlling the operation of the electronic device and ear buds, the ear buds each have a housing with a main body portion that is configured to be inserted into the ear of the user and an elongated stem portion that extends from the main body portion. The ear buds comprise proximity sensors on the main body.

Document <CIT> discloses a hearing aid including an earpiece with a first proximity sensor, a second proximity sensor and a control unit. The first proximity sensor is configured to transfer a first proximity signal to the control unit and the second proximity sensor is configured to transfer a second proximity signal to the control unit. The earpiece can be inserted into the external auditory canal of a user of the hearing device for operating the hearing device. The control unit is configured to control an operating mode of the hearing device according to changes in the first proximity signal and the second proximity signal.

In accordance with an aspect of the present disclosure, there is provided an earbud. The earbud comprises a capacitive sensor including at least one conductive trace and a controller configured to provide an indication of the earbud being inserted into an ear of a user responsive to detecting changes in capacitance of one of the at least one conductive trace relative to ground or different conductive traces relative to one another.

In some implementations, the earbud further comprises a nozzle configured to be inserted into at least an entrance of an ear canal of the user and the at least one inserted into the ear of the user and an elongated stem portion that extends from the main body portion. The ear buds comprise proximity sensors on the main body.

Document <CIT> discloses a hearing aid including an earpiece with a first proximity sensor, a second proximity sensor and a control unit. The first proximity sensor is configured to transfer a first proximity signal to the control unit and the second proximity sensor is configured to transfer a second proximity signal to the control unit. The earpiece can be inserted into the external auditory canal of a user of the hearing device for operating the hearing device. The control unit is configured to control an operating mode of the hearing device according to changes in the first proximity signal and the second proximity signal.

In accordance with an aspect of the present invention, there is provided an earbud according to claim <NUM>.

In some implementations, the earbud further comprises a nozzle configured to be inserted into at least an entrance of an ear canal of the user and the at least one conductive trace is disposed on the nozzle. The at least one conductive trace may include portions extending at least partially about a perimeter of the nozzle. The earbud may further include a conductive element disposed within the nozzle. The controller may be configured to detect changes in capacitance between the conductive element and the at least one conductive trace.

In some implementations, the earbud further comprises an insulator disposed on the at least one conductive trace.

The earbud may further include redundant conductive traces and the controller may be configured to calibrate the capacitive sensor based on a capacitance between the redundant conductive traces.

In some implementations, the controller is further configured to differentiate between signals from the capacitive sensor indicative of insertion of the earbud in the ear of the user and signals from the capacitive sensor indicative of manual handling of the earbud.

In some implementations, the controller is further configured to cause the earbud to transition from an active state to an inactive state responsive to the capacitive sensor providing a signal indicative of the earbud being removed from the ear of the user.

In some implementations, the controller is further configured to cause the earbud to transition from an active state to an inactive state responsive to the capacitive sensor failing to providing a signal indicative of the earbud being inserted into the ear of the user after a set time after activation of the earbud.

In accordance with another aspect, there is provided a method of reducing power consumption of an earbud according to claim <NUM>.

In some implementations, the method further comprises causing the earbud to transition from the active to the inactive state responsive to failing to determine that the earbud is inserted into the ear of the user after a set time after the earbud is placed into the active state.

In some implementations, the method further comprises causing the earbud to transition from the active to the inactive state responsive to determining that the earbud has transitioned from a state in which the earbud is inserted into the ear of the user to a state in which the earbud is not inserted into the ear of the user.

In some implementations, the method further comprises determining a degree of seal of the earbud in the ear of the user from the measurement of capacitance. The method may further comprise instructing the user to reposition the earbud to achieve a better seal of the earbud in the ear of the user. The method may further comprise modifying noise cancelling functionality of the earbud based on the degree of seal.

In some implementations, the method further comprises detecting movement of the earbud within the ear of the user based on the measurement of capacitance.

In some implementations, the method further comprises calibrating a capacitance meter in electrical communication with the at least one conductive trace by setting a reference capacitance at a capacitance detected between redundant traces disposed on the earbud.

In some implementations, the at least one conductive trace is disposed on an outside of a nozzle of the earbud and the method comprises obtaining the measurement of capacitance readings by measuring capacitance between the at least one conductive trace and a conductive element disposed within the nozzle.

In accordance with another aspect of the present invention, there is provided a method as defined in claim <NUM>.

The method comprises measuring a capacitance of one of at least one conductive trace disposed on the earbud relative to ground or different conductive traces disposed on the earbud relative to one another and providing an indication of the earbud being inserted into the ear of the user responsive to the capacitance exceeding a threshold capacitance value.

Aspects and implementations disclosed herein are not limited to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. Aspects and implementations disclosed herein are capable of being practiced or of being carried out in various ways.

Aspects and implementations disclosed herein may be applicable to a wide variety of audio devices structured to be at least partly inserted into one or both ears of a user (e.g., so called "in-ear" audio devices or "intra-aural" audio devices), hereinafter referred to also as "wireless earbuds" or simply "earbuds," and audio players. The examples discussed herein are directed primarily to earbuds, which may be wired or wireless, but the technology disclosed may also have application to over-the-ear earphones or other audio devices. It should be noted that although specific implementations of wireless earbuds primarily serving the purpose of acoustically outputting audio are presented with some degree of detail, such presentations of specific implementations are intended to facilitate understanding through provision of examples, and should not be taken as limiting the scope of the invention, which is defined by the appended claims.

Aspects and implementations disclosed herein may be applicable to earbuds that either do or do not support two-way communications, and either do or do not support active noise reduction (ANR). For earbuds that do support either two-way communications or ANR, it is intended that what is disclosed and claimed herein is applicable to an earbud incorporating one or more microphones disposed on a portion of the earbud that remains outside an ear when in use (e.g., feedforward microphones), on a portion that is inserted into a portion of an ear when in use (e.g., feedback microphones), or disposed on both of such portions. Still other implementations of earbuds to which what is disclosed and what is claimed herein is applicable will be apparent to those skilled in the art.

Various implementations and examples disclosed herein may provide for increased battery life in wireless earbuds by automatically causing the earbuds to turn off or deactivate when not in use. Further, various implementations and examples disclosed herein may provide for automatic control of audio playback in wired or wireless earbuds, for example to play audio when in use and pause audio when not in use. In some implementations, wireless earbuds are provided with one or more sensors that may be used to determine if the earbuds are inserted into the ear of a user. If a user removes an earbud from the ear of the user without first terminating rendering of audio by the earbud, the earbud may detect that it has been removed from the ear of the user and may automatically pause audio, or terminate rendering of audio and turn the earbud off, optionally after a set time after being removed from the ear of the user. In some implementations, if a user turns on an earbud and does not insert it into the ear of the user within a set time period, the earbud may automatically shut off.

In various implementations, earbuds may include one or more capacitive sensors. The one or more capacitive sensors may include conductive traces disposed on one or more portions of the wireless earbuds. The dielectric constant of the environment about the conductive traces is a factor that affects the capacitance between pairs of conductive traces or between the conductive traces and ground. The dielectric constant of human flesh is different than that of other materials or air and thus, as the conductive traces on an earbud are brought into proximity of the ear of a user, the capacitance between pairs of the conductive traces or between the conductive traces and ground changes. This change in capacitance may be detected by circuitry associated with the capacitive sensor or sensors. A degree of insertion of the earbud into the ear of a user may be determined by the capacitance between the conductive traces of the capacitive sensor or between the conductive traces and ground. Movement of the earbud into, out of, or from one position to another within the ear of the user may be determined by changes in capacitance between the conductive traces of the capacitive sensor or between the conductive traces and ground. The capacitive sensor may be calibrated to determine when an earbud is fully inserted into the ear of a user based upon measurements of capacitance between the conductive traces of the capacitive sensor or between the conductive traces and ground. Dummy or redundant conductive traces may be utilized to determine a baseline capacitance against which capacitance between the conductive traces or between the conductive traces and ground of the capacitive sensor used to detect insertion into the ear of the user may be compared to account for changes in moisture (e.g., sweat), eartips on the earbuds, or other environmental factors that may affect capacitance between the conductive traces or between the conductive traces and ground.

In some implementations, at least one conductive trace may be placed on a portion of an earbud that is designed to be inserted into the ear of a user during use, for example, an ear canal or nozzle portion of an earbud. Circuitry associated with the capacitive sensor may measure capacitance between one or multiple pairs of conductive traces or between at least one conductive trace and ground to determine, for example, whether the earbud is inserted into the ear of a user, if the earbud is fully inserted into the ear of the user, if the earbud forms an acceptable seal with the ear of the user, etc. In some implementations capacitance is measured between a conductive element disposed within or inside of the canal portion of the earbud and capacitive traces disposed on an external portion of the earbud, for example, the canal portion, in addition to, or as an alternative to measurements of capacitance between a pair or pairs of the conductive traces on the external portion of the earbud or between at least one of the conductive traces and ground.

In some implementations, acoustic processing circuitry associated with an earbud may modify one or more parameters of audio provided through the earbud based at least in part on a degree of fit or degree of insertion of the earbud into the ear of a user determined by the capacitance measurements made by the capacitive sensor. For example, the acoustic processing circuitry may modify one or more parameters of audio provided through the earbud to account for acoustic leakage associated with the earbud having a less than optimal degree of fit or insertion in the ear of the user. The one or more parameters of the audio may include, for example, volume or different equalization applied to different frequencies of audio rendered by the earbud.

Capacitive sensors in earbuds as disclosed herein may be used to manage battery life. The sensor could provide feedback on how well the earbud is seated in the ear canal of the user and adjust audio calibration accordingly.

The sensor output is specifically conducive to in-ear earbuds where it detects insertion inside the ear canal and not simply proximity to the ear. Detecting insertion of an earbud into an ear of a user rather than simply proximity of the earbud to the ear of the user is advantageous as it significantly reduces the pulse rate needed for detection to further improve battery life. An insertion detection method is an absolute threshold measurement that can be done infrequently.

<FIG>, taken together, provide two views of one implementation of an earbud <NUM>. <FIG> are schematic representations of one possible earbud configuration. The ideas described herein apply to other configurations (for example, as shown in the additional figures included herein), so long as there is space (e.g., canal/nozzle portion) to put at least one conductive trace. The earbud <NUM> of <FIG> has a casing made up of at least a canal portion <NUM> (also referred to herein as a nozzle portion) meant to be positioned within at least an entrance of an ear canal of a user's ear and a concha portion <NUM> meant to be positioned within at least a portion of the concha of the user's ear. More specifically, and as depicted, the concha portion <NUM> has a curved shape to fit within the concha of a user's ear while accommodating the shape of the concha as defined by portions of the tragus, anti-tragus, and anti-helix of the pinna of the ear. This curved configuration has a pair of extensions <NUM> and defines an inner periphery <NUM>. The canal portion <NUM> has a generally tubular shape extending from where one end of the canal portion <NUM> is coupled to the concha portion <NUM> at a location coincident with where the entrance to the ear canal is typically located in relation to the portion of the concha defined by portions of the tragus and anti-tragus. An aperture <NUM> is formed in the other end of the canal portion <NUM> to enable sounds to be acoustically output by an acoustic driver (e.g., element <NUM> illustrated in <FIG>) positioned within the casing of the earbud <NUM> through the aperture <NUM> and into the ear canal when the earbud <NUM> is properly positioned in the ear of a user during operation.

The implementation of the earbuds <NUM> depicted in <FIG> may be any of a variety of types of earbuds able to perform any of a variety of audio functions including, and not limited to, an in-ear earphone to acoustically output audio, an in-ear ANR device to provide a reduction in environmental noise sounds encountered by a user through the acoustic output of anti-noise sounds, and/or a two-way communications audio device employing detection of the user's speech sounds through bone conduction and/or an Eustachian tube connected to portions of the ear into which the in-ear audio device <NUM> is inserted. Further, it should be noted that although the concha portion <NUM> has been depicted and described as having a curved shape to fit within the concha, other implementations are possible having a somewhat differently shaped concha portion <NUM> that does not fill as much of the concha, or fills more of the concha.

The earbud <NUM> may receive audio through a wired or wireless coupling with another device. Accordingly, electrical and electronic components such as, but not limited to, a wireless receiver and/or transmitter, processor (optionally including ANR circuitry), battery, microphone, and acoustic driver may be included within the concha portion <NUM> and/or canal portion <NUM> of the earbud <NUM>. Alternatively, such components may be included within a housing or casing coupled to the earbud.

Examples of earbuds <NUM> disclosed herein are not limited to the form factors illustrated in <FIG>. Other examples of form factors for earbuds are illustrated in <FIG>. The earbuds may be coupled by wiring as illustrated in <FIG> and <FIG> to form headsets or may be mechanically separate, as illustrated in <FIG>. In various examples, the canal portion <NUM> or eartip may be separable from the concha portion <NUM> or may include a removable covering made of, for example, soft silicone to enhance comfort for a user. For example, in <FIG>, section 100A may include a rigid shell housing electronics such as an acoustic driver, wireless communication circuitry, battery, etc., while section 100B may be a removable eartip formed of a soft compliant material, for example, medical grade silicone.

Examples of earbuds <NUM> disclosed herein may have cross-sections similar to that illustrated in <FIG>. In the example illustrated in <FIG> an outer leg <NUM> may extend from the body of the earbud, similar to concha portion <NUM> in <FIG> to retain the earbud in the ear of a user. A sealing structure <NUM> is provided to engage the entrance to the user's ear canal and defines an output aperture <NUM>. An entrance cavity <NUM> to an acoustic nozzle <NUM> having an interior volume <NUM> may be provided proximal to an acoustic driver <NUM>. Driver <NUM> is enclosed in a driver cavity <NUM> including a front cavity <NUM> having a first volume and a back cavity <NUM> having a second volume. An entrance cavity <NUM> may be formed in front of driver cavity <NUM> that transitions to an entrance aperture <NUM> of the nozzle <NUM>. In the implementation shown in <FIG>, the output aperture <NUM> of nozzle <NUM> is significantly larger than the entrance aperture <NUM>. A first acoustic mesh <NUM> is provided at the entrance aperture <NUM> of the acoustic nozzle proximate the acoustic driver <NUM>, and a second acoustic mesh <NUM> is provided at the output aperture of the acoustic nozzle <NUM> distal from acoustic driver <NUM>.

<FIG> show partially cut-away views of two different variants of an earbud <NUM> including sensor systems for determining if the earbud <NUM> is inserted into the ear of a user. It is to be understood that the form factor illustrated in <FIG> is not limiting, and earbud <NUM> may alternatively have any of the form factors illustrated in <FIG> or other form factors known in the art. The sensor systems may include at least one conductive trace <NUM> disposed on a portion of the earbud <NUM>, for example, the outside of the canal portion <NUM>. As illustrated in <FIG>, the conductive traces <NUM> may extend at least partially or substantially wholly about a periphery of the outer surface of the canal portion <NUM>. Connective traces <NUM> provide electrical communication between the conductive traces <NUM> and control/monitor circuitry <NUM> of the earbud <NUM>. The conductive traces <NUM> may have widths of about <NUM> mils (<NUM>), thicknesses of between about <NUM> mil (<NUM>) and <NUM> mils, and may be separated by about <NUM> mils, although these dimensions are non-limiting examples. The connective traces <NUM> may have similar dimensions as the conductive traces <NUM>. The conductive traces <NUM> and/or connective traces <NUM> may be formed of, for example, metal film or other conductive material and may be deposited on the earbud <NUM> using methods known in the art, for example, using methods similar to those for depositing conductive traces on printed circuit boards.

Conductive traces <NUM> that are closer to the concha portion <NUM> of the earbud <NUM> than the aperture <NUM> of the canal portion <NUM> may extend about the periphery of the canal portion <NUM> to a lesser degree than conductive traces <NUM> located closer to the aperture <NUM> of the canal portion <NUM> to allow room for the connective traces <NUM> associated with each individual conductive trace <NUM> to extend along a length of the canal portion <NUM>. A conductive trace <NUM> closest to the aperture <NUM> of the canal portion <NUM> among all of the conductive traces <NUM> may extend completely about the periphery of the canal portion <NUM>. Alternatively or additionally, insulating material, for example, a thin film of insulting plastic <NUM> may be provided over the conductive traces <NUM> and/or between connective traces <NUM> to prevent short circuits between the conductive traces <NUM> and/or connective traces <NUM> or to provide for the connective traces <NUM> to overlap so that the conductive traces <NUM> may each extend substantially or completely about the periphery of the canal portion <NUM> of the earbud <NUM>.

As described more fully below, the control/monitor circuitry <NUM> of the earbud <NUM> is configured to measure capacitance between different pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground to determine if the earbud is inserted properly into the ear of a user and/or provides an acceptable fit and seal in the ear of the user. In other examples, one or more internal conductive traces or a conductive coating <NUM>, illustrated in <FIG> and <FIG>, may be disposed within at least a portion of the canal portion <NUM> of the earbud <NUM>, for example, on an internal surface of the canal portion <NUM> of the earbud <NUM>. In implementations in which such internal conductive traces or conductive coating <NUM> are present the control or monitor circuitry <NUM> of the earbud <NUM> may additionally or alternatively be configured to measure capacitance between at least one or different conductive traces <NUM> and the internal conductive traces or conductive coating <NUM> to determine if the earbud is inserted properly into the ear of a user and/or provides a good fit and seal in the ear of the user. In a further example illustrated in <FIG>, the conductive traces <NUM> may be combined with the connective traces <NUM> and may extend along the outside (and/or the inside) of canal portion <NUM> substantially parallel with an axis A of the canal portion <NUM>. The skilled artisan will recognize that other configurations and arrangements of the conductive traces <NUM> and/or connective traces <NUM> may be implemented in other examples. For example, the conductive traces <NUM> and/or connective traces <NUM> may extend helically around or inside the canal portion <NUM> of the earbud <NUM>. The number of conductive traces <NUM> and connective traces <NUM> illustrated is not intended to be limiting and other examples of earbuds may include fewer or greater number of conductive traces <NUM> and/or connective traces <NUM> than illustrated.

In another implementation, illustrated in <FIG>, a canal portion 110A of the earbud <NUM> may be formed from a plurality of stacked washers <NUM>. The bodies of the washers <NUM> may be formed of a non-conducive material, for example, a type of plastic commonly used to form the bodies or canal portions of earbuds. Conductive material <NUM>, for example, a metal film disposed on or within faces of the washers <NUM> may perform the function of the conductive traces <NUM> described with reference to the other examples disclosed herein. Connective traces <NUM> may provide electrical connection between the different layers of conductive material <NUM> and the monitor or control circuitry of the earbud similar to how the connective traces <NUM> provide electrical connection to the circuitry <NUM> as illustrated in, for example, <FIG> and <FIG>.

In some implementations, one or more pairs of conductive traces <NUM> (which may be referred to as dummy or redundant conductive traces) may be utilized to measure a baseline capacitance against which the capacitance between other conductive traces <NUM> or between at least one conductive trace <NUM> and ground (and/or between at least one conductive trace <NUM> and internal conductive traces or conductive coating <NUM>) may be compared to obtain capacitance measurements used to determine if the earbud is inserted properly into the ear of a user and/or provides an acceptable fit and seal in the ear of the user. This baseline capacitance may change based on changes that occur to the ear of the user, for example, after exercise when the blood vessels of the ear may be more open and the inside of the ear may include sweat or during cold weather during which the blood vessels in the ear may contract. The baseline capacitance may also change if a user switches between different types of removable eartips on the canal portion of the earbud <NUM>. Other changes in the physical condition of a user can also bring about minor alterations in the dimensions and/or shape of the ear canal that may alter a baseline capacitance of between conductive traces <NUM>. The capacitance between the active (non-dummy or redundant) conductive traces <NUM> or between at least one conductive trace <NUM> and ground (or between at least one conductive trace <NUM> and internal conductive traces or conductive coating <NUM>) may be compared against the baseline capacitance so that changes in the baseline capacitance do not cause the monitoring circuitry <NUM> of the earbud to derive incorrect conclusions regarding the degree of insertion or fit of the earbud in the ear of the user based on uncompensated capacitance measurements between the active conductive traces <NUM> or between at least one conductive trace <NUM> and ground. In some examples, the dummy or redundant conductive traces <NUM> are dedicated to proving baseline capacitive measurements, but in other examples, control circuitry of the earbud may periodically switch the functionality of the dummy or redundant conductive traces <NUM> from providing baseline capacitance measurements to providing capacitive measurements used to determine the degree of insertion or fit of the earbud in the ear of the user.

The eartips of the earbuds <NUM> illustrated in <FIG> are represented by elements <NUM>. Alternate examples of eartips, which may be removable ear tips that may be used with examples of earbuds disclosed herein, are illustrated in <FIG> and <FIG>, indicated generally at <NUM>. These ear tips <NUM> have a configuration that includes a body <NUM> that rests in at least a part of the concha, a retaining leg <NUM> that rests against and applies pressure to the antihelix, and an outlet <NUM> that fits within at least an entrance in the ear canal. The ear tip <NUM> illustrated in <FIG> further includes a flexible flap <NUM> around the outlet. The construction and configuration of the removable ear tips <NUM> illustrated in <FIG> and <FIG> are described in further detail in commonly owned <CIT> and <CIT>.

Both variants of the earbud <NUM> illustrated in <FIG> may incorporate circuitry <NUM> and an acoustic driver <NUM> that is electrically coupled to the circuitry <NUM>. Within the canal portion <NUM>, a channel <NUM> is formed that extends from the aperture <NUM> through to an interior portion <NUM> of the concha portion <NUM>. Within the concha portion <NUM>, the interior portion <NUM> is separated by a wall structure and the acoustic driver <NUM> from another interior portion <NUM> in which the circuitry <NUM> is depicted as being disposed (though it should be noted that the circuitry <NUM> may be disposed in any of a variety of locations either within the casing of the earbud <NUM>, or externally thereof). The earbuds <NUM> further include a battery <NUM> to power the various components and wireless communication circuitry built into the circuitry <NUM> or a separate circuit element (though this may also be located in a housing separate from earbud <NUM>). The earbud <NUM> may also include a microphone <NUM> that is acoustically coupled to the channel <NUM> and/or the interior portion <NUM> and electrically coupled to the circuitry <NUM> for providing two-way communications through the earbud <NUM> or feedback-based ANR. Optionally, the earbud <NUM> may be activated or deactivated with a manually operable power switch <NUM>.

Both of the variants of <FIG> are depicted as having an aperture <NUM> formed between the interior portion <NUM> and the environment external to a user's ear. One or more of the apertures <NUM> may serve as acoustic ports to tune the frequency response of the acoustic driver <NUM> and/or may serve to enable equalization of air pressure between the ear canal and the external environment. The apertures <NUM> may have dimensions and/or other physical characteristics selected to acoustically couple portions within the casing of the earbud <NUM> to each other and/or to the external environment within a selected range of frequencies. Further, one or more damping elements (not shown), for example, a screen or foam insert, may be disposed within one or more of the apertures <NUM> to cooperate with characteristics of the acoustic driver <NUM> to alter frequency response.

Additionally or alternatively, one or more of the apertures <NUM> may be formed in the concha portion <NUM> (and/or in other portions of the casing) to provide a controlled acoustic leak between the ear canal and the external environmental for purposes of controlling the effects of variations in fit that may develop over time. As will be recognized by those skilled in the art, variations in the health or other aspects of the physical condition of a user can bring about minor alterations in the dimensions and/or shape of the ear canal over time such that the quality of the seal able to be formed with each insertion of the earbud <NUM> into the ear over time may change. Thus, in some implementations, the dimensions and/or other characteristics of one or more apertures <NUM> formed in the casing may be selected to aid in mitigating the effects of a slightly degraded quality of seal by providing a pre-existing leak of controlled characteristics that mitigates the acoustic effects of other leaks developing in the future in the seal between the casing of the earbud <NUM> and portions of the ear. For example, the dimensions of one or more apertures <NUM> may be selected to be large enough to provide a far greater coupling between the ear canal and the external environment than any other coupling through a leak in the seal that may develop at a later time.

The conductive traces <NUM> and/or internal conductive traces or conductive coating <NUM> may be electrically coupled to the circuitry <NUM>. Various of the conductive traces <NUM> and/or internal conductive traces or conductive coating <NUM> may receive drive signals from the circuitry <NUM>. Measurements of capacitance between pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground (and/or internal conductive traces or conductive coating <NUM>) may be obtained from electrical measurements (e.g., voltage potential) taken from undriven conductive traces <NUM> by the circuitry <NUM>. In various implementations, either a dedicated controller, or part of a System on Chip integrated circuit, may be used to determine the capacitance between pairs of conductive traces <NUM> (and/or internal conductive traces or conductive coating <NUM>). One example of a controller that may be used to determine the capacitance between pairs of conductive traces <NUM> (and/or internal conductive traces or conductive coating <NUM>) to determine the relative position of the sensing electrodes with respect to the ear canal is a Cypress PSoC <NUM> series controller with built-in capacitance sensing.

When the earbud <NUM> is not inserted into the ear of a user, capacitance between different pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground (and/or internal conductive traces or conductive coating <NUM>) may be at a first level defined by factors such as geometry of the conductive traces and the dielectric constant of the medium surrounding the conductive traces, e.g., air. When the earbud <NUM> is inserted into the ear of a user, the dielectric constant of the flesh of the ear canal causes the capacitance between pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground to change, for example, to increase, thus providing an indication that the earbud <NUM> is inserted into the ear of the user. As a user inserts the earbud <NUM> into the ear of the user capacitance between conductive traces <NUM> closer to the aperture <NUM> end of the canal portion <NUM> change before capacitance between conductive traces <NUM> closer to the concha <NUM> end of the canal portion <NUM> change. The circuitry <NUM> may detect this pattern of capacitance changes to determine that the earbud <NUM> is being inserted into the ear of the user. The extent to which the capacitance between different pairs of conductive traces <NUM> changes may provide an indication of the degree of insertion of the earbud into the ear of the user. In some examples, the earbud may provide the user with an indication of the depth of insertion of the earbud in the ear of the user, for example, by the circuitry <NUM> causing the acoustic driver <NUM> to emit sound pulses or tones that vary depending on a degree of insertion of the earbud into the ear of the user. In other examples, the earbud could emit a signal when the insertion reaches an optimal point, for example, a point at which the earbud is fully inserted into the ear of the user. As the earbud is removed from the ear of the user, the opposite pattern may be observed - for example, capacitance between conductive traces <NUM> closer to the concha <NUM> end of the canal portion <NUM> change before capacitance between conductive traces <NUM> closer to the aperture <NUM> end of the canal portion <NUM> change. The circuitry <NUM> may detect this pattern of capacitance changes to determine that the earbud <NUM> is being removed from the ear of the user and in some examples may provide an indication of same to the user, for example, by providing an audio tone or pattern through the acoustic driver <NUM> that varies depending on a degree of insertion of the earbud into the ear of the user. Indications may also be provided via a user interface of an application running on a device connected to the earbud wirelessly. In some examples, the earbud may automatically shut down responsive to detecting a pattern of capacitance changes indicative of the earbud having been removed from the ear of the user.

In some implementations, the circuitry <NUM> may be configured to differentiate between a pattern of capacitance changes between pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground that would be observed when inserting or removing the earbud <NUM> from the ear of the user and a pattern of capacitance changes between pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground that would be observed when a user is manually handling the earbud <NUM>. For example, as described above the capacitance between pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground may change in a predictable pattern as the earbud <NUM> is inserted or removed from the ear of the user. A different pattern of observed changes in capacitance between pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground may be recognized by the circuitry <NUM> as being indicative of manual handling of the earbud <NUM> and may be ignored with regard to determining a degree of insertion of the earbud <NUM> in the ear of the user.

In some examples, once the earbud <NUM> has been fully inserted into the ear of the user, the measured capacitance between different conductive traces or between at least one conductive trace and ground may provide an indication of a degree of fit of the earbud in the ear of the user. For example, if the capacitance between certain pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground is different, e.g., less than would be expected if a proper fit were achieved, the circuitry may determine that the earbud is not properly inserted and may provide an indication of same to the user, for example, by emitting a tone or other sound pattern, or via a user interface of an application running on a device connected to the earbud wirelessly. Such a tone, sound pattern, or user interface output may be considered instructions from the circuitry to the user to reposition the earbud <NUM> into a more proper position in the ear of the user. If the measured capacitance levels are consistent with the earbud <NUM> being properly inserted into the ear of the user, the circuitry <NUM> may cause the earbud to emit a tone or beep or provide another indication of proper insertion to the user. In both instances, the earbud could additionally or alternatively emit an audio message, such as "the ear bud is not fully inserted" or "the ear bud is properly inserted. " In another example, if the measured capacitance between different pairs of conductive traces <NUM> or between at least one conductive trace <NUM> and ground is not steady, this may indicate that the earbud <NUM> is loose in the ear of the user. The circuitry may provide an indication to the user that the earbud <NUM> is loose so that the user might, for example, reinsert the earbud or try a different removable eartip that may provide a better degree of fit in the ear of the user.

<FIG> provides a block diagram of a controller <NUM> with which insertion of an earbud as disclosed herein within an ear of a user may be detected. The controller <NUM> may be included within the body of an earbud, for example, within circuitry <NUM>. The controller may be formed on a circuit board <NUM>. Each earbud in a pair of earbuds may include a controller <NUM>, or a single controller <NUM> may control operation of both earbuds in a pair and may communicate via a wired or wireless connection between the two earbuds in the pair.

The controller <NUM> incorporates a voltage control <NUM> to controllably provide a driving voltage to one or more conductive traces <NUM> disposed on or in the canal portion <NUM> of an earbud <NUM>. The controller <NUM> also incorporates a user interface <NUM> which may wirelessly communicate with an external system, for example, a cell phone or computer, for receiving programming or providing recorded information, a storage <NUM> in which is stored a control routine <NUM>, and a processing device <NUM> coupled to the storage <NUM> to access and execute a sequence of instructions of the control routine <NUM>. The processing device <NUM> is also coupled to the voltage control <NUM> to operate the voltage control <NUM> to effect the application of a controlled voltage to the one or more of the conductive traces <NUM> and is further coupled to the receiver interface <NUM> which receives signals from one or more receiving conductive traces <NUM> disposed on or in the canal portion of an earbud <NUM>. The controller <NUM> also incorporates at least an earpiece interface <NUM> to enable coupling of the controller <NUM> to the built-in microphone <NUM> and the acoustic driver <NUM> to be driven to acoustically output various test sounds that may be used to help calibrate the determination of insertion of earbuds in the ear of a user by the controller <NUM>. In some implementations separate voltage controllers <NUM> are provided for each driven conductive trace <NUM> in an earbud or pair of earbuds, and in other implementations, a single voltage controller <NUM> is used with each driven conductive trace in an earbud or pair of earbuds. Similarly, in some implementations separate receiver interfaces <NUM> are provided for each receiving conductive trace <NUM> in an earbud or pair of earbuds, and in other implementations, a single receiver interface <NUM> is used with each receiving conductive trace <NUM> in an earbud or pair of earbuds.

An implementation of a method of operating an earbud <NUM> with a capacitive earbud insertion sensor as shown in <FIG> is illustrated in the flowchart of <FIG>, indicated generally at <NUM>. In act <NUM> a user activates the earbud. The user may activate the earbud by pressing a power switch. Additionally or alternatively, the earbud may include an accelerometer, for example, a microelectromechanical accelerometer built into the circuitry of the earbud that detects movement of the earbud and may activate the earbud when a user picks up the earbud. Further, the earbud may activate when the capacitive sensor detects changes in capacitance between conductive traces or between at least one conductive trace and ground indicative of manual handling of the earbud. Activation of the earbud may cause a timer to begin counting down (acts <NUM>, <NUM>). Upon expiration of the timer (act <NUM>) the earbud controller may determine whether a signal from driven capacitive traces being received at receiving conductive traces or a capacitance between at least one conductive trace and ground is consistent with the at least one conductive trace or conductive traces being located in the ear canal of the user to determine if the earbud is inserted into the ear of the user (act <NUM>). In some embodiments, the earbud controller determines that the earbud is inserted into the ear of the user if a signal from the receiving conductive traces or between at least one conductive trace and ground was indicative of the capacitance between the driven and receiving conductive traces or between at least one conductive trace and ground having increased over a period of time from a first time to a second time. A threshold amount of capacitance change, for example, at least about <NUM>% or at least about <NUM>% change in capacitance as compared to an expected change in capacitance may be set for determining if the earbud is inserted into the ear of the user.

If the earbud was determined to be properly inserted in the ear of the user in decision act <NUM>, the earbud may optionally provide an indication of proper insertion being detected, for example, by emitting a click or a tone (act <NUM>) and the earbud may begin to render audio content (act <NUM>). In some embodiments, the earbud need not wait for the timer to expire but may continuously check for proper insertion of the earbud after the earbud is activated and may provide an indication of proper insertion being detected and begin to render audio any time prior to expiration of the timer.

If the earbud was not determined to be properly inserted in the ear of the user in decision act <NUM> or prior to expiration of the timer, the earbud may optionally provide an indication of improper insertion (act <NUM>), for example, a pattern of clicks or a tone different from that used to provide an indication of proper insertion of the earbud in the ear of the user. The earbud may then begin and await expiration of a second timer (acts <NUM>, <NUM>) and if the earbud is not determined to be properly inserted in the ear of the user prior to or at the time of expiration of the second timer (act <NUM>), the earbud controller may deactivate the earbud (act <NUM>). If, however, in decision act <NUM> the earbud controller determines that the earbud is properly inserted into the ear of the user it may optionally provide an indication of proper insertion being detected, for example, by emitting a click or a tone (act <NUM>) and the earbud may begin to render audio content (act <NUM>).

Periodically, for example, at a rate of between about <NUM> second, <NUM> seconds, <NUM> seconds, <NUM> seconds, <NUM> minute or <NUM> minutes, the earbud may recheck if it is still inserted into the ear of the user (act <NUM>). In addition, or alternatively, upon detection of an event, for example, detecting movement of the earbud via an accelerometer built into the earbud, the earbud may recheck if it is still inserted into the ear of the user (act <NUM>). If the earbud is still inserted into the ear of the user the earbud may continue rendering audio content. If in decision act <NUM> the earbud controller determines that the earbud is not still inserted into the ear of the user, for example, by determining that the capacitance between one or more pairs of conductive traces decreased to a level inconsistent with the earbud being disposed in the ear canal of the user, the method may proceed to act <NUM> and the earbud may provide the indication of improper insertion and be deactivated if not determined to be inserted into the ear of the user prior to expiration of the second timer (acts <NUM>-<NUM>).

It is to be understood the method illustrated in <FIG> may also be applicable to earbuds having a conductive trace or conductive coating internal to the canal portion of the earbud, for example, as in the earbud illustrated in <FIG>. The method illustrated in <FIG> may also be applicable to detecting proper insertion of both earbuds in a pair of earbuds. For example, in decision acts <NUM>, <NUM>, and <NUM>, the earbud controller may make a determination if one or both of the earbuds in a pair of earbuds are properly inserted into the ear of a user, may cause audio content to be rendered through one or both earbuds in act <NUM>, and may deactivate one or both earbuds in the pair in act <NUM>.

Having thus described several aspects of at least one implementation, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art.

Accordingly, the foregoing description and drawings are by way of example only.

Claim 1:
An earbud (<NUM>) comprising:
a capacitive sensor including at least one conductive trace (<NUM>);
a circuitry (<NUM>);
an acoustic driver (<NUM>) that is electrically coupled with the circuitry (<NUM>); and
a controller (<NUM>) included in the circuitry (<NUM>) and configured to provide an indication of the earbud being inserted into an ear of a user responsive to detecting changes in capacitance of one of the at least one conductive trace (<NUM>) relative to ground or different conductive traces (<NUM>) relative to one another;
wherein the at least one conductive trace (<NUM>) is constructed and arranged to exhibit a capacitance that increase with a depth of insertion of the earbud (<NUM>) in the ear of the user;
wherein the controller (<NUM>) is further configured to provide feedback to the user of whether the earbud (<NUM>) is inserted into the ear of the user by the circuitry (<NUM>) causing the acoustic driver (<NUM>) to emit sound pulses or tones that vary depending on a degree of insertion of the earbud (<NUM>) into the ear of the user.