Patent ID: 12238469

DETAILED DESCRIPTION

Representative applications of methods and apparatus according to the present application are described in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting.

In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting; such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments.

Headphones have been in production for many years, but numerous design problems remain. For example, the functionality of headbands associated with headphones has generally been limited to a mechanical connection functioning only to maintain the earpieces of the headphones over the ears of a user and provide an electrical connection between the earpieces. Furthermore, the incorporation of headphones into other types of portable listening devices, such as augmented reality and virtual reality headsets has also been slow due to an unwillingness to adapt headphones to new and improved form factors. The headband tends to add substantially to the bulk of the headphones, thereby making storage of the headphones problematic. Stems connecting the headband to the earpieces that are designed to accommodate adjustment of an orientation of the earpieces with respect to a user's ears also add bulk to the headphones. Stems connecting the headband to the earpieces that accommodate elongation of the headband generally allow a central portion of the headband to shift to one side of a user's head. This shifted configuration can look somewhat odd and depending on the design of the headphones can also make the headphones less comfortable to wear.

While some improvements such as wireless delivery of media content to the headphones has alleviated the problem of cord tangle, this type of technology introduces its own batch of problems. For example, because wireless headphones require battery power to operate, a user who leaves the wireless headphones turned on could inadvertently exhaust the battery of the wireless headphones, making them unusable until a new battery can be installed or for the device to be recharged. Another design problem with many headphones is that a user must generally figure out which earpiece corresponds to which ear to prevent the situation in which the left audio channel is presented to the right ear and the right audio channel is presented to the left ear.

A solution to the unsynchronized positioning of the earpieces is to incorporate an earpiece synchronization component taking the form of a mechanical mechanism disposed within the headband that synchronizes the distance between the earpieces and respective ends of the headband. This type of synchronization can be performed in multiple ways. In some embodiments, the earpiece synchronization component can be a cable extending between both stems that can be configured to synchronize the movement of the earpieces. The cable can be arranged in a loop where different sides of the loop are attached to respective stems of the earpieces so that motion of one earpiece away from the headband causes the other earpiece to move the same distance away from the opposite end of the headband. Similarly, pushing one earpiece towards one side of the headband translates the other earpiece the same distance towards the opposite side of the headband. In some embodiments, the earpiece synchronization component can be a rotating gear embedded within the headband can be configured to engage teeth of each stem to keep the earpieces synchronized.

One solution to the conventional bulky connections between headphones stems and earpieces is to use a spring-driven pivot mechanism to control motion of the earpieces with respect to the band. The spring-driven pivot mechanism can be positioned near the top of the earpiece, allowing it to be incorporated within the earpiece instead of being external to the earpiece. In this way, pivoting functionality can be built into the earpieces without adding to the overall bulk of the headphones. Different types of springs can be utilized to control the motion of the earpieces with respect to the headband. Specific examples that include torsional springs and leaf springs are described in detail below. The springs associated with each earpiece can cooperate with springs within the headband to set an amount of force exerted on a user wearing the headphones. In some embodiments, the springs within the headband can be low spring-rate springs configured to minimize the force variation exerted across a large spectrum of users with different head sizes. In some embodiments, the travel of the low-rate springs in the headband can be limited to prevent the headband from clamping to tightly about the neck of a user when being worn around the neck.

One solution to the large headband form-factor problem is to design the headband to flatten against the earpieces. The flattening headband allows for the arched geometry of the headband to be compacted into a flat geometry, allowing the headphones to achieve a size and shape suitable for more convenient storage and transportation. The earpieces can be attached to the headband by a foldable stem region that allows the earpieces to be folded towards the center of the headband. A force applied to fold each earpiece in towards the headband is transmitted to a mechanism that pulls the corresponding end of the headband to flatten the headband. In some embodiments, the stem can include an over-center locking mechanism that prevents inadvertent return of the headphones to an arched state without requiring the addition of a release button to transition the headphones back to the arched state.

A solution to the power management problems associated with wireless headphones includes incorporating an orientation sensor into the earpieces that can be configured to monitor an orientation of the earpieces with respect to the band. The orientation of the earpieces with respect to the band can be used to determine whether or not the headphones are being worn over the ears of a user. This information can then be used to put the headphones into a standby mode or shut the headphones down entirely when the headphones are not determined to be positioned over the ears of a user. In some embodiments, the earpiece orientation sensors can also be utilized to determine which ears of a user the earpieces are currently covering. Circuitry within the headphones can be configured to switch the audio channels routed to each earpiece in order to match the determination regarding which earpiece is on which ear of the user.

These and other embodiments are discussed below with reference toFIGS.1-31E; however, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting.

Symmetric Telescoping Earpieces

FIG.1Ashows a front view of an exemplary set of over ear or on-ear headphones100. Headphones100includes a band102that interacts with stems104and106to allow for adjustability of the size of headphones100. In particular, stems104and106are configured to shift independently with respect to band102in order to accommodate multiple different head sizes. In this way, the position of earpieces108and110can be adjusted to position earpieces108and110directly over the ears of a user. Unfortunately, as can be seen inFIG.1B, this type of configuration allows stems104and106to become mismatched with respect to band102. The configuration shown inFIG.1Bcan be less comfortable for a user and additionally lack cosmetic appeal. To remedy these issues, the user would be forced to manually adjust stems104and106with respect to band102in order to achieve a desirable look and comfortable fit.FIGS.1A-1Balso show how stems104and106extend down to a central portion of earpieces108in order to allow earpieces108to rotate to accommodate the curvature of a user's head. As mentioned above the portions of stems104and106that extend down around earpieces108increase the diameters of earpieces108.

FIG.2Ashows a perspective view of headphones200with a headband202configured to solve the problems depicted inFIGS.1A-1B. Headband202is depicted without a cosmetic covering to reveal internal features. In particular, headband202can include a wire loop204configured to synchronize the movement of stems206and208. Wire guides210can be configured to maintain a curvature of wire loop204that matches the curvature of leaf springs212and214. Leaf springs212and214can be configured to define the shape of headband202and to exert a force upon the head of a user. Each of wire guides210can include openings through which opposing sides of wire loop204and leaf springs212and214can pass. In some embodiments, the openings for wire loop204can be defined by low-friction bearings to prevent noticeable friction from impeding the motion of wire loop204through the openings. In this way, wire guides210define a path along which wire loop204extends between stem housings216and218. Wire loop204is coupled to both stem206and stem208and functions to maintain a distance120between an earpiece122and stem housing116substantially the same as a distance124between earpiece126and stem housing118. A first side204-1of wire loop204is coupled to stem206and a second side204-2of wire loop204is coupled to stem208. Because opposite sides of the wire loop are attached to stems206and208movement of one of the stems results in movement of the other stem in the same direction.

FIG.2Bshows a cross-sectional view of a portion of stem housing116in accordance with section line A-A. In particular,FIG.2Bshows how a protrusion228of stem206engages part of wire loop204. Because protrusion228of stem206is coupled with wire loop204, when a user of headphones100pulls earpiece222farther away from stem housing216, wire loop204is also pulled causing wire loop204to circulate through headband202. The circulation of wire loop204through headband202adjusts the position of earpieces226, which is similarly coupled to wire loop204by a protrusion of stem208. In addition to forming a mechanical coupling with wire loop204, protrusion228can also be electrically coupled to wire loop204. In some embodiments, protrusion228can include an electrically conductive pathway230that electrically couples wire loop204to electrical components within earpiece222. In some embodiments, wire loop204can be formed from an electrically conductive material, so that signals can be transferred between components within earpieces222and226by way of wire loop204.

FIG.2Cshows another cross-sectional view of stem housing116in accordance with section line B-B. In particular,FIG.2Cshows how wire loop204engages pulley232within stem housing216. Pulley232minimizes any friction generated by the movement of earpiece222closer or farther away from stem housing216. Alternatively, wire loop204can be routed through a static bearing within stem housing216.

FIG.2Dshows another perspective view of headphones200. In this view, it can be seen that first side204-1and second side204-2of wire loop204shift laterally as they cross from one side of headband202to the other. This can be accomplished by the openings defined by wire guides210being gradually offset so that by the time sides204-1and204-2reach stem housing218, second side204-2is centered and aligned with stem208, as depicted inFIG.2E.

FIG.2Eshows how second side204-2is engaged by protrusion234. Because stems206and208are attached to respective first and second sides of wire loop204, pushing earpiece226towards stem housing218also results in earpiece222being pushed towards stem housing216. Another advantage of the configuration depicted inFIGS.2A-2Eis that regardless of the direction of travel of stems206and208, wire loop204always stays in tension. This keeps the amount of force needed to extend or retract earpieces222and226consistent regardless of direction.

FIGS.2F-2Gshow perspective views of headphones250.

Headphones250are similar to headphones200with the exception that only a single leaf spring252is used to connect stem housing254to stem housing256. In this embodiment, wire loop258can be positioned to either side of leaf spring252. Instead of being positioned directly below one side of wire loop258, stems260and262can be positioned directly between the two sides of wire loop258and connected to one side of wire loop258by an arm of stems260and262.

FIGS.2H and2Ishow cross-sectional views of an interior portion of stem housings254and256.FIG.2Hshows a cross-sectional view of stem housing254in accordance with section line D-D.FIG.2Hshows how stem260can include a laterally protruding arm268that engages wire loop258. In this way, laterally protruding arm268couples stem260to wire loop258so that when earpiece264is moved earpiece266is kept in an equivalent position.FIG.2Ishows a cross-sectional view of stem housing256in accordance with section line E-E.FIG.2Ialso shows how wire loop258can be routed within stem housing256by pulleys270and272. By routing wire loop258above stem262any interference between wire loop258and stem206can be avoided.

FIGS.3A-3Cshow another headphones embodiment configured to solve problems described inFIGS.1A-1B.FIG.3Ashows headphones300, which includes headband assembly302. Headband assembly302is joined to earpieces304and306by stems308and310. A size and shape of headband assembly302can vary depending on how much adjustability is desirable for headphones300.

FIG.3Bshows a cross-sectional view of headband assembly302when headphones300are expanded to their largest size. In particular,FIG.3Bshows how headband assembly302includes a gear312configured to engage teeth defined by the ends of each of stems308and310. In some embodiments, stems308and310can be prevented from pulling completely out of headband assembly302by spring pins314and316by engaging openings defined by stems308and310.

FIG.3Cshows a cross-sectional view of headband assembly302when headphones300are contracted to a smaller size. In particular,FIG.3Cshows how gear312keeps the position of stems308and310synchronized on account of any movement of stem308or stem310being translated to the other stem by gear312. In some embodiments, a stiffness of the housing defining the exterior of headband assembly302can be selected to match the stiffness of stems308and310to provide a user of headphones300with a headband having a more consistent feel.

FIG.3Dshows an alternative embodiment of stems308and310. A cover concealing the ends of stems308and310has been removed to more clearly show the features of the mechanism synchronizing the positions of the stems. Stem308defines an opening318extending through a portion of stem308. One side of opening318has teeth configured to engage gear320. Similarly, stem310defines an opening322extending through a portion of stem310. One side of opening322has teeth configured to engage gear320. Because opposing sides of openings318and322engage gear320, any motion of one of stems308and310causes the other stem to move. In this way, earpieces positioned at the ends of each of stem308and stem310are synchronized.

FIG.3Eshows a top view of stems308and310.FIG.3Ealso shows an outline of a cover324for concealing the geared openings defined by stems308and310and controlling the motion of the ends of stems308and310.FIG.3Fshows a cross-sectional side view of stems308and310covered by cover324. Gear320can include bearing326for defining the axis of rotation for gear320. In some embodiments, the top of bearing326can protrude from cover324, allowing a user to adjust the earpiece positions by manually rotating bearing326. It should be appreciated that a user could also adjust the earpiece positions by simply pushing or pulling on one of stems308and310.

FIG.3Gshows a flattened schematic view of another earpiece synchronization system that utilizes a loop328within a headband330(the rectangular shape is used merely to show the location of headband330and should not be construed as for exemplary purposes only) to keep a distance between each of earpieces304and306and headband330synchronized. Stem wires332and334couple respective earpieces304and306to loop328. Stem wires332and334can be formed of metal and soldered to opposing sides of loop328. Because stem wires332and334are coupled to opposing sides of loop328, movement of earpiece306in direction336results in stem wire332moving in direction338. Consequently, moving earpiece306into closer proximity with headband330also moves stem wire332, which results in earpiece304being brought into closer proximity with headband330. In addition to showing a new location of earpieces304and306after being moved into closer proximity to headband330,FIG.3Hshows how moving earpiece304in direction340automatically moves earpiece306in direction342and farther away from headband330. While not depicted it should be appreciated that headband330could include various reinforcement members to keep loop328and stem wires332and334in the depicted shapes.

FIGS.3I-3Jshow a flattened schematic view of another earpiece synchronization system similar to the one depicted inFIGS.3G-3H.FIG.3Ishows how the ends of stems344and346can be coupled directly to each other without an intervening loop. By extending stems344and346into a pattern having a similar shape as loop328a similar outcome can be achieved without the need for an additional loop structure. Movement of stems344and346is assisted by reinforcement members348,350and352, which help to prevent buckling of stems344and346while the position of earpieces304and306are being adjusted. Reinforcement members348-352can define channels through which stems344and346smoothly pass. These channels can be particularly helpful in locations where stems344and346curve. While not defining a curved channel, reinforcement member352still serves an important purpose of limiting the direction of travel of the ends of stems344and346to directions354and356. Movement in direction356results in earpieces moving toward headband330, as depicted inFIG.3J. Movement in direction354results in earpieces304and306moving farther away from headband330.

FIGS.3K-3Lshow cutaway views of headphones360that are suitable for incorporation of either one of the earpiece synchronization systems depicted inFIGS.3G-3J.FIG.3Kshows headphones360with earpieces retracted and stem wires332and334extending out of headband330to engage and synchronize a position of stem assembly362with a position of stem assembly364. Stem334is depicted coupled to support structure366within stem assembly364, which allows extension and retraction of stem334to keep stem assembly362synchronized with stem assembly364. As depicted, stem assembly362is disposed within a channel defined by headband330, which allows stem assembly362to move relative to headband330.FIG.3Kalso shows how data synchronization cable368can extend through headband330and wrap around a portion of both stem wire334and stem wire332. By wrapping around stem wires332and334, data synchronization cable368is able to act as a reinforcement member to prevent buckling of stem wires332and334. Data synchronization cable368is generally configured to exchange signals between earpieces304and306in order to keep audio precisely synchronized during playback operations of headphones360.

FIG.3Lshows how the coil configuration of data synchronization cable368accommodates extension of stem assemblies362and364. Data synchronization cable368can have an exterior surface with a coating that allows stem wires332and334to slide through a central opening defined by the coils.FIG.3Lalso shows how earpieces304and306maintain the same distance from a central portion of headband330.

FIGS.3M-3Nshow perspective views of the earpiece synchronization system depicted inFIGS.3G-3Hin retracted and extended positions as well as a data synchronization cable368.FIG.3Mshows how stem wire332includes an attachment feature370that at least partially surrounds a portion of loop328. In this way, stem wire332, stem wire334and support structures366move along with loop328.FIG.3Malso shows a dashed line illustrating how a covering for headband330can at least partially conform with loop328, stem wire332and stem wire334.

FIG.30shows a portion of canopy structure372and how an earpiece synchronization system can be routed through reinforcement members374of canopy structure372. Reinforcement members374help guide loop328and stem wire332along a desired path. In some embodiments, canopy structure372can include a spring mechanism that helps keep earpieces secured to a user's ears.

FIGS.3P-3Qshow gearing located at opposing ends of a headband assembly for another alternative earpiece synchronization system. In particular,FIG.3Pshows how stem262has a first end coupled to an earpiece (not depicted) and a second end coupled to gear380. By pulling on the earpiece a force382can be exerted upon stem262, which causes gear380to rotate due to its engagement of rack gear384. Gear380is rigidly coupled to beveled gear component386. Beveled gear component386in turn induces rotation of beveled gear component388. Beveled gear component388is rigidly coupled to gear390. Rotation of gear390in turn induces rotation of elongated gear392. Gears380,386,388and390all move together and are guided along a periphery of elongated gear392by bearing394. Elongated gear392is in turn coupled to a flexible rotary shaft that includes a cable396routed through an associated headband assembly. Cable396can include layers of high-tensile wire wound over each other at opposing pitch angles that are configured to efficiently transmit rotational motion from one end of cable396to another. Rotation of the other end of cable396in turn moves a stem at the other end of the headband assembly in sync with stem262. A diameter of cable396can be between about 0.02 inches and 0.25 inches.FIG.3Qshows a second position of gears380,386,388and390after having adjusted a position of stem262.

Off-Center Pivoting Earpieces

FIGS.4A-4Bshow front views of headphones400having off-center pivoting earpieces.FIG.4Ashows a front view of headphones400, which includes headband assembly402. In some embodiments, headband assembly402can include an adjustable band and stems for customizing the size of headphones400. Each end of headband assembly402is depicted being coupled to an upper portion of earpieces404. This differs from conventional designs, which place the pivot point in the center of earpieces404so that earpieces can naturally pivot in a direction that allows earpieces404to move to an angle in which earpieces404are positioned parallel to a surface of a user's head. Unfortunately, this type of design generally requires bulky arms that extend to either side of earpiece404, thereby substantially increasing the size and weight of earpieces404. By locating pivot point406near the top of earpieces404, associated pivot mechanism components can be packaged within earpieces404.

FIG.4Bshows an exemplary range of motion408for each of earpieces404. Range of motion408can be configured to accommodate a majority of users based on studies performed on average head size measurements. This more compact configuration can still perform the same functions as the more traditional configuration described above, which includes applying a force through the center of the earpiece and establishing an acoustic seal. In some embodiments, range of motion408can be about 18 degrees. In some embodiments, range of motion408may not have a defined stop but instead grow progressively harder to deform as it gets farther from a neutral position. The pivot mechanism components can include spring elements configured to apply a modest retaining force to the ears of a user when the headphones are in use. The spring elements can also bring earpieces back to a neutral position once headphones400are no longer being worn.

FIG.5Ashows an exemplary pivot mechanism500for use in the upper portion of an earpiece. Pivot mechanism500can be configured to accommodate motion around two axes, thereby allowing adjustments to both roll and yaw for earpieces404with respect to headband assembly402. Pivot mechanism500includes a stem502, which can be coupled to a headband assembly. One end of stem502is positioned within bearing504, which allows stem502to rotate about yaw axis506. Bearing504also couples stem502to torsional springs508, which oppose rotation of stem502with respect to earpiece404about roll axis510. Each of torsional springs508can also be coupled to mounting blocks512. Mounting blocks512can be secured to an interior surface of earpiece404by fasteners514. Bearing504can be rotationally coupled to mounting blocks512by bushings516, which allow bearing504to rotate with respect to mounting blocks512. In some embodiments, the roll and yaw axes can be substantially orthogonal with respect to one another. In this context, substantially orthogonal means that while the angle between the two axes might not be exactly 90 degrees that an angle between the two axes would stay between 85 and 95 degrees.

FIG.5Aalso depicts magnetic field sensor518. Magnetic field sensor518can take the form of a magnetometer or Hall Effect sensor capable of detecting motion of a magnet within pivot mechanism500. In particular, magnetic field sensor518can be configured to detect motion of stem502with respect to mounting blocks512. In this way, magnetic field sensor518can be configured to detect when headphones associated with pivot mechanism500are being worn. For example, when magnetic field sensor518takes the form of a Hall Effect sensor, rotation of a magnet coupled with bearing504can result in the polarity of the magnetic field emitted by that magnet saturating magnetic field sensor518. Saturation of the Hall Effect sensor by a magnetic field causes the Hall Effect sensor to send a signal to other electronic devices within headphones400by way of flexible circuit520.

FIG.5Bshows a pivot mechanism500positioned behind a cushion522of earpiece404. In this way, pivot mechanism500can be integrated within earpiece404without impinging on space normally left open to accommodate the ear of a user. Close-up view524shows a cross-sectional view of pivot mechanism500. In particular, close-up view524shows a magnet526positioned within a fastener528. As stem502is rotated about roll axis510, magnet526rotates with it. Magnetic field sensor518can be configured to sense rotation of the field emitted by magnet526as it rotates. In some embodiments, the signal generated by magnetic field sensor518can be used to activate and/or deactivate headphones400. This can be particularly effective when the neutral state of earpiece404corresponds to the bottom end of each earpiece404is oriented towards the user at an angle that causes earpiece404to be rotated away from the users head when worn by most users. By designing headphones400in this manner, rotation of magnet526away from its neutral position can be used as a trigger that headphones400are in use. Correspondingly, movement of magnet526back to its neutral position can be used as an indicator that headphones400are no longer in use. Power states of headphones400can be matched to these indications to save power while headphones400are not in use.

Close up view524ofFIG.5Balso shows how stem502is able to twist within bearing504. Stem502is coupled to threaded cap530, which allows stem502to twist within bearing504about yaw axis506. In some embodiments, threaded cap530can define mechanical stops that limit the range of motion through which stem502can twist. A magnet532is disposed within stem502and is configured to rotate along with stem502. A magnetic field sensor534can be configured to measure the rotation of a magnetic field emitted by magnet532. In some embodiments, a processor receiving sensor readings from magnetic field sensor534can be configured to change an operating parameter of headphones400in response to the sensor readings indicating a threshold amount of change in the angular orientation of magnet532relative to the yaw axis has occurred.

FIG.6Ashows a perspective view of another pivot mechanism600that is configured to fit within a top portion of earpieces404of headphones. The overall shape of pivot mechanism600is configured to conform with space available within the top portion of the earpieces. Pivot mechanism600utilizes leaf springs instead of torsion springs to oppose motion in the directions indicated by arrows601of earpieces404. Pivot mechanism600includes stem602, which has one end disposed within bearing604. Bearing604allows for rotation of stem602about yaw axis605. Bearing604also couples stem602to a first end of leaf spring606through spring lever608. A second end of each of leaf springs606is coupled to a corresponding one of spring anchors610. Spring anchors610are depicted as being transparent so that the position at which the second end of each of leaf springs606engages a central portion of spring anchors610can be seen. This positioning allows leaf springs606to bend in two different directions. Spring anchors610couple the second end of each leaf spring606to earpiece housing612. In this way, leaf springs606create a flexible coupling between stem602and earpiece housing612. Pivot mechanism600can also include cabling614configured to route electrical signals between two earpieces404by way of headband assembly402(not depicted).

FIGS.6B-6Dshow a range of motion of earpiece404.FIG.6Bshows earpiece404in a neutral state with leaf springs606in an undeflected state.FIG.6Cshows leaf springs606being deflected in a first direction andFIG.6Dshows leaf spring606being deflected in a second direction opposite the first direction.FIGS.6C-6Dalso show how the area between cushion522and earpiece housing612can accommodate the deflection of leaf springs606.

FIG.6Eshows an exploded view of pivot mechanism600.FIG.6Edepicts mechanical stops that govern the amount of rotation possible about yaw axis605. Stem602includes a protrusion616, which is configured to travel within a channel defined by an upper yaw bushing618. As depicted, the channel defined by upper yaw bushing618has a length that allows for greater than 180 degrees of rotation. In some embodiments, the channel can include a detent configured to define a neutral position for earpiece404.FIG.6Ealso depicts a portion of stem602that can accommodate yaw magnet620. A magnetic field emitted by magnet620can be detected by magnetic field sensor622. Magnetic field sensor622can be configured to determine an angle of rotation of stem602with respect to the rest of pivot mechanism600. In some embodiments, magnetic field sensor622can be a Hall Effect sensor.

FIG.6Ealso depicts roll magnet624and magnetic field sensor626, which can be configured to measure an amount of deflection of leaf springs606. In some embodiments, pivot mechanism600can also include strain gauge628configured to measure strain generated within leaf spring606. The strain measured in leaf spring606can be used to determine which direction and how much leaf spring is being deflected. In this way, a processor receiving sensor readings recorded by strain gauge628can determine whether and in which direction leaf springs606are bending. In some embodiments, readings received from strain gauge can be configured to change an operating state of headphones associated with pivot mechanism600. For example, the operating state can be changed from a playback state in which media is being presented by speakers associated with pivot mechanism600to a standby or inactive state in response to the readings from the strain gauge. In some embodiments, when leaf springs606are in an undeflected state this can be indicative of headphones associated with pivot mechanism600not being worn by a user. In other embodiments, the strain gauge can be positioned upon a headband spring. For this reason, ceasing playback based on this input can be very convenient as it allows a user to maintain a location in a media file until putting the headphones back on the head of the user at which point the headphones can be configured to resume playback of the media file. Seal630can close an opening between stem602and an exterior surface of an earpiece in order to prevent the ingress of foreign particulates that could interfere with the operation of pivot mechanism600.

FIG.6Fshows a perspective view of another pivot mechanism650, which differs in some ways from pivot mechanism600. Leaf springs652have a different orientation than leaf springs606of pivot mechanism600. In particular, leaf springs652are oriented about 90 degrees different than leaf springs606. This results in a thick dimension of leaf springs652opposing rotation of an earpiece associated with pivot mechanism650. FIG.6F also shows flexible circuit654and board-to-board connector656. Flexible circuit can electrically couple a strain gauge positioned upon leaf spring652to a circuit board or other electrically conductive pathways on pivot mechanism650. In some embodiments, sensor data provided by the strain gauge can be configured to determine whether or not headphones associated with pivot mechanism650are being worn by a user of the headphones. Pivot mechanism650is also depicted including a portion658of a stem configured to attach pivot mechanism650to a headband.

FIG.6Gshows another pivot assembly660attached to earpiece housing612by fasteners662and bracket663. Pivot assembly660can include multiple helical springs664arranged side by side. In this way, helical coils664can act in parallel increasing the amount of resistance provided by pivot assembly660. Helical springs664are held in place and stabilized by pins666and668. Actuator670translates any force received from rotation of stem base658to helical springs664. In this way, helical springs664can establish a desired amount of resistance to rotation of stem base658.

FIGS.6H-6Ishow pivot assembly660with one side removed in order to illustrate rotation of stem base658in different positions. In particular,FIGS.6H-6Ishows how rotation of stem base658results in rotation of actuator670and compression of helical springs664.

FIG.6Jshows a cutaway perspective view of pivot assembly660disposed within earpiece housing612. In some embodiments, stem base658can include a bearing674, as depicted, to reduce friction between stem base658and actuator670.FIG.6Jalso shows how bracket663can define a bearing for securing pin666in place. Pins666and668are also shown defining flattened recesses for keeping helical springs664securely in place. In some embodiments, the flattened recess can include protrusions that extends into central openings of helical springs664.

FIGS.6K-6Lshow partial cross-sectional side views of pivot assembly660positioned within earpiece housing with helical springs664in relaxed and compressed states. In particular, the motion undergone by actuator670when shifting from a first position inFIG.6Kto a second position of maximum deflection is clearly depicted.FIGS.6K and6Lalso depict mechanical stop676which helps limit an amount of rotation earpiece housing can achieve relative to stem base.

FIGS.6M-6Nshow side views of two different rotational positions of stem base672isolated from its pivot assembly. In particular two permanent magnets678and680are shown rigidly coupled to stem base672. Permanent magnets678and680emit magnetic fields with polarities oriented in opposing directions. Magnetic field sensor682is mounted to earpiece housing612such that magnetic field sensor682remains motionless relative to stem base672during rotation of stem base672about axis of rotation684. In this way, at a first position depicted inFIG.6M, magnetic field sensor682is positioned proximate permanent magnet680and at a second position depicted inFIG.6N, magnetic field sensor682. The opposing polarities of permanent magnets678and682allow magnetic field sensor682to distinguish between the two depicted positions. In some embodiments, the positions can vary by about 20 degrees; however, a total range of motions of stem base672can vary between about 10 and 30 degrees. In some embodiments, magnetic field sensor682can take the form of a magnetometer or a Hall Effect sensor. Depending on a sensitivity of magnetic field sensor682, magnetic field sensor682can be configured to measure an approximate angle of stem base672relative to earpiece housing612. For example, where the depicted rotational positions differ by 20 degrees an intermediate position of 10 degrees could be inferred by sensor readings from magnetic field sensor682where the magnetic field directions transition from one direction to another. In some embodiments, magnetic field sensor682can be configured to operate with only a single permanent magnet and be configured to determine rotational position of stem base672based solely on a magnetic field strength detected by magnetic field sensor682. It should be noted that in alternative embodiments magnetic field sensor682can be coupled to stem base672and permanent magnets678and680can be coupled to earpiece housing resulting in magnetic field sensor682moving within the earpiece housing.

Low Spring-Rate Band

FIG.7Ashows multiple positions of a spring band700suitable for use in a headband assembly. Spring band700can have a low spring rate that causes a force generated by the band in response to deformation of spring band700to change slowly as a function of displacement. Unfortunately, the low spring rate also results in the spring having to go through a larger amount of displacement before exerting a particular amount of force. Spring band700is depicted in different positions702,704,706and708. Position702can correspond to spring band700being in a neutral state at which no force is exerted by spring band700. At position704, a spring band700can begin exerting a force pushing spring band700back toward its neutral state. Position706can correspond to a position at which users with small heads bend spring band700when using headphones associated with spring band700. Position708can correspond to a position of spring band700in which the users with large heads bend spring band700. The displacement between positions702and706can be sufficiently large for spring band700to exert an amount of force sufficient to keep headphones associated with spring band700from falling off the head of a user. Further, due to the low spring rate the force exerted by spring band700at position708can be small enough so that use of headphones associated with spring band700is not high enough to cause a user discomfort. In general, the lower the spring rate of spring band700, the smaller the variation in force exerted by spring band700. In this way, use of a low spring-rate spring band700can allow headphones associated with spring band700to give users with different sized heads a more consistent user experience.

FIG.7Bshows a graph illustrating how spring force varies based on spring rate as a function of displacement of spring band700. Line710can represent spring band700having its neutral position equivalent to position702. As depicted, this allows spring band700to have a relatively low spring rate that still passes through a desired force in the middle of the range of motion for a particular pair of headphones. Line712can represent spring band700having its neutral position equivalent to position704. As depicted, a higher spring rate is required to achieve a desired amount of force being exerted in the middle of the desired range of motion. Finally, line714represents spring band700having its neutral position equivalent to position706. Setting spring band700to have a profile consistent with line714would result in no force being exerted by spring band700at the minimum position for the desired range of motion and over twice the amount of force exerted compared with spring band700having a profile consistent with line710at the maximum position. While configuring spring band700to travel through a greater amount of displacement prior to the desired range of motion has clear benefits when wearing headphones associated with spring band700, it may not be desirable for the headphones to return to position702when worn around the neck of a user. This could result in the headphones uncomfortably clinging to the neck of a user.

FIG.8A-8Bshow a solution for preventing discomfort caused by headphones800utilizing a low spring-rate spring band from wrapping too tightly around the neck of a user. Headphones800include a headband assembly802joining earpieces804. Headband assembly802includes compression band806coupled to an interior-facing surface of spring band700.FIG.8Ashows spring band700in position708, corresponding to a maximum deflection position of headphones800. The force exerted by spring band700can act as a deterrent to stretching headphones800past this maximum deflection position. In some embodiments, an exterior facing surface of spring band700can include a second compression band configured to oppose deflection of spring band700past position708. As depicted, knuckles808of compression band806serve little purpose when spring band is in position708on account of none of the lateral surfaces of knuckles808being in contact with adjacent knuckles808.

FIG.8Bshows spring band700in position706. At position706, knuckles808come into contact with adjacent knuckles808to prevent further displacement of spring band700towards position704or702. In this way, compression band806can prevent spring band700from squeezing the neck of a user of headphones800while maintaining the benefits of the low-spring rate spring band700.FIGS.8C-8Dshow how separate and distinct knuckles808can be arranged along the lower side of spring band700to prevent spring band700from returning past position706.

FIGS.8E-8Fshow how the use of springs to control the motion of headband assembly802with respect to earpieces804can change the amount of force applied to a user by headphones800when compared to the force applied by spring band700alone.FIG.8Eshows forces810exerted by spring band700and forces812exerted by springs controlling the motion of earpieces804with respect to headband assembly802.FIG.8Fshows exemplary curves illustrating how forces810and812supplied by at least two different springs can vary based on spring displacement. Force810does not begin to act until just prior to the desired range of motion on account of the compression band preventing spring band700from returning all the way to a neutral state. For this reason, the amount of force imparted by force810begins at a much higher level, resulting in a smaller variation in force810.FIG.8Falso illustrates force814, the result of forces810and812acting in series. By arranging the springs in series, a rate at which the resulting force changes as headphones800change shape to accommodate the size of a user's head is reduced. In this way, the dual spring configuration helps to provide a more consistent user experience for a user base that includes a great diversity of head shapes.

FIGS.8G-8Hshow another way in which to limit the range of motion of a pair of headphones850using a low spring-rate band852.FIG.8Gshows cable854in a slack state on account of earpieces856being pulled apart. The range of motion of low spring-rate band852can be limited by cable854achieving a similar function to the function of compression band806, engaging as a result of function of tension instead of compression. Cable854is configured to extend between earpieces856and is coupled to each of earpieces856by anchoring features858. Cable854can be held above low spring-rate band852by wire guides860. Wire guides860can be similar to wire guides210depicted inFIGS.2A-2G, with the difference that wire guides860are configured to elevate cable854above low spring-rate band852. Bearings of wire guides860can prevent cable854from catching or becoming undesirably tangled. It should be noted that cable854and low spring-rate band852can be covered by a cosmetic cover. It should also be noted that in some embodiments, cable854could be combined with the embodiments shown inFIGS.2A-2Gto produce headphones capable of synchronizing earpiece position and controlling the range of motion of the headphones.

FIG.8Hshows how when earpieces856are brought closer together cable854tightens and eventually stops further movement of earpieces856closer together. In this way, a minimum distance862between earpieces856can be maintained that allows headphones850to be worn around the neck of a broad population of users without squeezing the neck of the user too tightly.

Left/Right Ear Detection

FIG.9Ashows an earpiece902of headphones positioned over an ear904of a user. Earpiece902includes at least proximity sensors906and908. Proximity sensors906and908are positioned within a recess defined by earpiece902resulting in detectably different readings being returned by proximity sensors906and908depending on which ear earpiece902is positioned over. This is possible due to the asymmetric geometry of most user's ears. In some embodiments, proximity sensor906includes a light emitter configured to emit infrared light and an optical receiver configured to detect the emitted light reflecting off ear904of the user. A processor incorporated within or electrically coupled to proximity sensor906can be configured to determine a distance between proximity sensor906and proximate portions of ear904by measuring the amount of time it takes for infrared pulses emitted by the light emitter to return back to the light detector. In some embodiments, proximity sensor906can also be configured to map a contour of a portion of the ear. This can be accomplished with multiple emitters configured to emit light of different frequencies in different directions. Sensor readings collected by one or more optical receivers configured to detect and distinguish the different frequencies can then be used to determine a distance between proximity sensor906and different locations on the ear. In some embodiments, proximity sensors906can be distributed around a circumference of earpiece902when even more detail about the shape and position of the ear with respect to the earpiece is desired. For example, in some embodiments, it may be desirable to in addition to identifying which ear the earpiece is positioned upon, identify a rotational position of the ear with respect to the earpiece. Sensor readings could be of sufficiently high quality to identify certain features of ear904such as for example an earlobe or a pinna. In some embodiments and as depicted an angle at which infrared light is emitted from proximity sensor908can be different than an angle at which infrared light is emitted from proximity sensor906. In this way, a likelihood of detecting an ear or the side of a user's head can be increased. As depicted, proximity sensor908would be able to achieve earlier detection due to it being pointed farther outside of the interior of earpiece902. Proximity sensor906with its shallower angle would be able to cover a larger area of ear904of the user. In some embodiments, a capacitive sensor array can be positioned just beneath the surface of earpiece902and be configured to identify protruding features of the ear that contact or are in close proximity to surface912of earpiece902.

FIG.9Bshows positions of capacitive sensors910beneath surface912and proximate ear contours914associated with ear904. Ear contours914represent those contours of ear904most likely to protrude closest to the array of capacitive sensors910. Capacitive sensors910can be configured to identify portions of the detected contours of ear904to determine which ear earpiece902is positioned upon as well as any rotation of earpiece902relative to ear904.FIG.9Balso indicates how both surface912and the array of capacitive sensors910define openings916or perforations through which audio waves are able to pass substantially unattenuated. While the array of capacitive sensors910are shown disposed beneath only a central portion of surface912, it should be appreciated that in some embodiments the array of capacitive sensors910could be arranged in different patterns resulting in a greater or smaller amount of coverage. For example, in some embodiments capacitive sensors910can be distributed across a majority of surface912in order to more completely characterize the shape and orientation of ear904. In some embodiments, the location and orientation data captured by capacitive sensors910and/or proximity sensors906/908can be used to optimize audio output from speaker disposed within earpiece902. For example, an earpiece with an array of audio drivers could be configured to actuate only those audio drivers centered upon or proximate ear904.

FIG.10Ashows a top view of an exemplary head of a user1000wearing headphones1002. Earpieces1004are depicted on opposing sides of user1000. A headband joining earpieces1004is omitted to show the features of the head of user1000in greater detail. As depicted, earpieces1004are configured to rotate about a yaw axis so they can be positioned flush against the head of user1000and oriented slightly towards the face of user1000. In a study performed upon a large group of users it was found that on average, earpieces1004when situated over the ears of a user were offset above the x-axis as depicted. Furthermore, for over 99% of users the angle of earpieces1004with respect to the x-axis was above the x-axis. This means that only a statistically irrelevant portion of users of headphones1002would have head shapes causing earpieces1004to be oriented forward of the x-axis.FIG.10Bshows a front view of headphones1002. In particular,FIG.10Bshows yaw axes of rotation1006associated with earpieces1004and how earpieces1004are both oriented toward the same side of headband1008joining earpieces1004.

FIGS.10C-10Dshow top views of headphones1002and how earpieces1004are able to rotate about yaw axes of rotation1006.FIGS.10C-10Dalso show earpieces1004being joined together by headband1008. Headband1008can include yaw position sensors1010, which can be configured to determine an angle of each of earpieces1004with respect to headband1008. The angle can be measured with respect to a neutral position of earpieces with respect to headband1008. The neutral position can be a position in which earpieces1004are oriented directly toward a central region of headband1008. In some embodiments, earpieces1004can have springs that return earpieces1004to the neutral position when not being acted upon by an external force. The angle of earpieces relative to the neutral position can change in a clockwise direction or counter clockwise direction. For example, inFIG.10Cearpiece1004-1is biased about axis of rotation1006-1in a counter clockwise direction and earpiece1004-2is biased about axis of rotation1006-2in a clockwise direction. In some embodiments, sensors1010can be time of flight sensors configured to measure angular change of earpieces1004. The depicted pattern associated and indicated as sensor1010can represent an optical pattern allowing accurate measurement of an amount of rotation of each of the earpieces. In other embodiments, sensors1010can take the form of magnetic field sensors or Hall Effect sensors as described in conjunction withFIGS.5B and6E. In some embodiments, sensors1010can be used to determine which ear each earpiece is covering for a user. Because earpieces1004are known to be oriented behind the x-axis for almost all users, when sensors1010detect both earpieces1004oriented to towards one side of the x-axis headphones1002can determine which earpieces are on which ear. For example,FIG.10Cshows a configuration in which earpiece1004-1can be determined to be on the left ear of a user and earpiece1004-2is on the right ear of the user. In some embodiments, circuitry within headphones1002can be configured to adjust the audio channels so the correct channel is being delivered to the correct ear.

Similarly,FIG.10Dshows a configuration in which earpiece1004-1is on the right ear of a user and earpiece1004-2is on the left ear of a user. In some embodiments, when earpieces are not oriented towards the same side of the x-axis, headphones1002can request further input prior to changing audio channels. For example, when earpieces1004-1and1004-2are both detected as being biased in a clockwise direction, a processor associated with headphones1002can determine headphones1002are not in current use. In some embodiments, headphones1002can include an override switch for the case where the user wants to flip the audio channels independent of the L/R audio channel routing logic associated with yaw position sensors1010. In other embodiments, another sensor or sensors can be activated to confirm the position of headphones1002relative to the user.

FIGS.10E-10Fshow flow charts describing control methods that can be carried out when roll and/or yaw of the earpieces with respect to the headband is detected.FIG.10Eshows a flow chart that describes a response to detection of rotation of earpieces with respect to a headband of headphones about a yaw axis. The yaw axes can extend through a point located near the interface between each earpiece and the headband. When the headphones are being used by a user, the yaw axes can be substantially parallel to a vector defining the intersection of the sagittal and coronal anatomical planes of the user. At1052, rotation of the earpieces about the yaw axes can be detected by a rotation sensor associated with a pivot mechanism. In some embodiments, the pivot mechanism can be similar to pivot mechanism500or pivot mechanism600, which depict yaw axes506and605. At1054, a determination can be made regarding whether a threshold associated with rotation about the yaw axis has been exceeded. In some embodiments, the yaw threshold can be met anytime the earpieces pass through a position where the ear-facing surfaces of the two earpieces can be facing directly towards one another. At1056, in the case where at least one of the earpieces passes through the threshold and both earpieces are determined to be oriented in the same direction, the audio channels being routed to the two earpieces can be swapped. In some embodiments, the user can be notified of the change in audio channels. In some embodiments, an amount of roll detected by the pivot mechanism can be factored into a determination of how to assign the audio channels.

FIG.10Fshows a flow chart that describes a method for changing the operating state of headphones based on sensor readings from one or more sensors of the headphones. At1062, prior to a final packaging operation headphones can be put in a hibernating state in which little or no power is expended. In this way, headphones1062can have a substantial amount of battery power left on delivery. Delivery personnel could carry out a special procedure in order to remove the headphones from the hibernation state. For example, a data connector engaged with a charging port of the headphones could be removed triggering removal from the hibernation state. At1063, the headphones can be in a suspended state whenever they have not been used for a threshold amount of time. In the suspended state sensor polling rates can be substantially reduced to further conserve power. In some embodiments, the headphones may take longer than normal to identify a user attempting to use the headphones. At1064, a strain gauge or capacitive sensor can be used to identify placement of the headphones on a user's head. In some embodiments, the method can include returning to the suspended state at1063when a motion time out occurs or a strain gauge indicates the headphones are not being worn. At1065, capacitive or proximity type sensors can be used to sense the presence and/or orientation of ears within the earpieces. At1066, once an orientation of the headphones on the user's head is identified, input controls can be activated. At1067, media playback can begin by routing audio channels received wirelessly or via a wired cable to corresponding earpieces. Removing headphones from a user's ears can result in a return to1064at which time the sensors can go back through the various steps to correctly identify earpiece locations and orientations.

FIG.10Gshows a system level block diagram of a computing device1070that can be used to implement the various components described herein, according to some embodiments. In particular, the detailed view illustrates various components that can be included in headphones1002illustrated inFIGS.10A-10D. As shown inFIG.10G, the computing device1070can include a processor1072that represents a microprocessor or controller for controlling the overall operation of computing device1070. The computing device1070can include first and second earpieces1074and1076joined by a headband assembly, the earpieces including speakers for presenting media content to the user. Processor1072can be configured to transmit first and second audio channels to first and second earpieces1074and1076. In some embodiments, first orientation sensor(s)1078can be configured to transmit orientation data of first earpiece1074to processor1072. Similarly, second orientation sensor(s)1080can be configured to transmit orientation data of second earpiece1076to processor1072. Processor1072can be configured to swap the 1st Audio Channel with the 2nd Audio Channel in accordance with information received from first and second orientation sensors1078and1080. A data bus1082can facilitate data transfer between at least battery/power source1084, wireless communications circuitry1084, wired communications circuitry1088computer readable memory1080and processor1072. In some embodiments, processor1072can be configured to instruct battery/power source1084in accordance with information received by first and second orientation sensors1078and1080. Wireless communications circuitry1086and wired communications circuitry1088can be configured to provide media content to processor1072. In some embodiments, processor1072, wireless communications circuitry1086and wired communications circuitry1088can be configured to transmit and receive information from computer-readable memory1090. Computer readable memory1090can include a single disk or multiple disks (e.g. hard drives) and includes a storage management module that manages one or more partitions within computer readable memory1090.

Foldable Headphones

FIGS.11A-11Bshow headphones1100having a deformable form factor.FIG.11Ashows headphones1100including deformable headband assembly1102, which can be configured to mechanically and electrically couple earpieces1104. In some embodiments, earpieces1104can be ear cups and in other embodiments, earpieces1104can be on-ear earpieces. Deformable headband assembly1102can be joined to earpieces1104by foldable stem regions1106of headband assembly1102. Foldable stem regions1106are arranged at opposing ends of deformable band region1108. Each of foldable stem regions1106can include an over-center locking mechanism that allows each of earpieces1104to remain in a flattened state after being rotated against deformable band region1108. The flattened state refers to the curvature of deformable band region1108changing to become flatter than in the arched state. In some embodiments, deformable band region1108can become very flat but in other embodiments the curvature can be more variable (as shown in the following figures). The over-center locking mechanism allows earpieces1104to remain in the flattened state until a user rotates the over-center locking mechanism back away from deformable band region1108. In this way, a user need not find a button to change the state, but simply perform the intuitive action of rotating the earpiece back into its arched state position.

FIG.11Bshows one of earpieces1104rotated into contact with deformable band region1108. As depicted, rotation of just one of earpieces1104against deformable band region1108causes half of deformable band region1108to flatten.FIG.11Cshows the second one of earpieces rotated against deformable band region1108. In this way, headphones1100can be easily transformed from an arched state (i.e.FIG.11A) to a flattened state (i.e.FIG.11C). In the flattened state headphones, the size of headphones1100can be reduced to a size equivalent to two earpieces arranged end to end. In some embodiments, deformable band region can press into cushions of earpieces1104, thereby substantially preventing headband assembly1102from adding to the height of headphones1100in the flattened state.

FIGS.11D-11Fshow how earpieces1104of headphones1150can be folded towards an exterior-facing surface of deformable band region1108.FIG.11Dshows headphones11D in an arched state. InFIG.11E, one of earpieces1104is folded towards the exterior-facing surface of deformable band region1108. Once earpiece1104is in place as depicted, the force exerted in moving earpiece1104to this position can place one side of deformable headband assembly1102in a flattened state while the other side stays in the arched state. InFIG.11F, the second earpiece1104is also shown folded against the exterior-facing

FIGS.12A-12Bshow a headphones embodiment in which the headphones can be transitioned from an arched state to a flattened state by pulling on opposing ends of a spring band.FIG.12Ashows headphones1200, which can be, for example, headphones1100shown inFIG.11, in a flattened state. In the flattened state, earpieces1104are aligned in the same plane so that each of earpads1202face in substantially the same direction. In some embodiments, headband assembly1102contacts opposing sides of each of earpads1202in the flattened state. Deformable band region1108of headband assembly1102includes spring band1204and segments1206. Spring band1204can be prevented from returning headphones1200to the arched state by locking components of foldable stem regions1106exerting pulling forces on each end of spring band1204. Segments1206can be connected to adjacent segments1206by pins1208. Pins1208allow segments to rotate relative to one another so that the shape of segments1206can be kept together but also be able to change shape to accommodate an arched state. Each of segments1206can also be hollow to accommodate spring band1204passing through each of segments1206. A central or keystone segment1206can include fastener1210, which engages the center of spring band1204. Fastener1210isolates the two side of spring band1204allowing for earpieces1104to be sequentially rotated into the flattened state as depicted inFIG.11B.

FIG.12Aalso shows each of foldable stem regions1106which include three rigid linkages joined together by pins that pivotally couple upper linkage1212, middle linkage1214and lower linkage1216together. Motion of the linkages with respect to each other can also be at least partially governed by spring pin1218, which can have a first end coupled to a pin1220joining middle linkage1214to lower linkage1216and a second end engaged within a channel1222defined by upper linkage1212. The second end of spring pin1218can also be coupled to spring band1204so that as the second end of spring pin1218slides within channel1222the force exerted upon spring band1204changes. Headphones1200can snap into the flattened state once the first end of spring pin1218reaches an over-center locking position. The over-center locking position keeps earpiece1104in the flattened position until the first end of spring pin1218is moved far enough to be released from the over-center locking position. At that point, earpiece1104returns to its arched state position.

FIG.12Bshows headphones1200arranged in an arched state. In this state, spring band1204is in a relaxed state where a minimal amount of force is being stored within spring band1204. In this way, the neutral state of spring band1204can be used to define the shape of headband assembly1102in the arched state when not being actively worn by a user.FIG.12Balso shows the resting state of the second end of spring pins1218within channels1222and how the corresponding reduction in force on the end of spring band1204allows spring band1204to help headphones1200assume the arched state. It should be noted that while substantially all of spring band1204is depicted inFIGS.12A-12Bthat spring band1204would generally be hidden by segments1206and upper linkages1212.

FIGS.12C-12Dshow side views of foldable stem region1106in arched and flattened states, respectively.FIG.12Cshows how forces1224exerted by spring pin1218operate to keep linkages1212,1214and1216in the arched state. In particular, spring pin1218keeps the linkages in the arched state by preventing upper linkage1212from rotating about pin1226and away from lower linkage1216.FIG.12Dshows how forces1228exerted by spring pin1218operate to keep linkages1212,1214and1216in the flattened state. This bi-stable behavior is made possible by spring pin1218being shifted to an opposite side of the axis of rotation defined by pin1226in the flattened state. In this way, linkages1212-1216are operable as an over-center locking mechanism. In the flattened state, spring pin1218resists transitioning the headphones from moving from the flattened state to the arched state; however, a user exerting a sufficiently large rotational force on earpiece1104can overcome the forces exerted by spring pin1218to transition the headphones between the flat and arched states.

FIG.12Eshows a side view of one end of headphones1200in the flattened state. In this view, earpads1202are shown with a contour configured to conform to the curvature of the head of a user. The contour of earpads1202can also help to prevent headband assembly1102and particularly segments1206making up headband assembly1102from protruding substantially farther vertically than earpads1202. In some embodiments, the depression of the central portion of earpads1202can be caused at least in part by pressure exerted on them by segments1206.

FIGS.13A-13Bshow partial cross-sectional views of headphones1300, which use an off-axis cable to transition between an arched state and a flattened state.FIG.13Ashows a partial cross-sectional view of headphones1300in an arched state. Headphones1300differ from headphones1200in that when earpieces1104are rotated towards headband assembly1102a cable1302is tightened in order to flatten deformable band region1108of headband assembly1102. Cable1302can be formed from a highly clastic cable material such as Nitinol™, a Nickel Titanium alloy. Close-up view1303shows how deformable band region1108can include many segments1304that are fastened to spring band1204by fasteners1306. In some embodiments, fasteners1306can also be secured to spring band1204by an O-ring to prevent any rattling of fasteners1306while using headphones1300. A central one of segments1304can include a sleeve1308that prevents cable1302from sliding with respect to the central one of segments1304. The other segments1304can include metal pulleys1310that keep cable1302from experiencing substantial amounts of friction as cable1302is pulled on to flatten headphones1300.FIG.13Aalso shows how each end of cable1302is secured to a rotating fastener1312. As foldable stem region1106rotates, rotating fasteners1312keeps the ends of cable1302from twisting.

FIG.13Bshows a partial cross-sectional view of headphones1300in a flattened state. Rotating fasteners1312are shown in a different rotational position to accommodate the change in orientation of cable1302. The new location of rotating fasteners1312also generates an over-center locking position that prevents headphones1300from being inadvertently returned to the arched state as described above with respect to headphones1200.FIG.13Balso shows how the curved geometry of each of segments1304allows segments1304to rotate with respect to one another in order to transition between the arched and flattened states. In some embodiments, cable1302can also be operative to limit a range of motion of spring band1204similar in some ways to the embodiment shown inFIGS.9A-9B. Headphones1300also include input panels1314affixed to an outward facing surface of headphones1300in the flattened state. Input panels1314can define a touch sensitive input surface allowing users to input operating instructions into headphones1300when headphones1300are in the flattened state. For example, a user might wish to continue media playback with headphones1300in the flattened state. Easy access to input panels1314would make controlling operation of headphones1300in this state straightforward and convenient.

FIG.14Ashows headphones1400that are similar to headphones1300. In particular, headphones1400also use cable1302to flatten deformable band region1108. Furthermore, a central portion of cable1302is retained by the central segment1304. In contrast, lower linkage1216of foldable stem region1106is shifted upward with respect to lower linkage1216depicted inFIG.12A. When earpiece1104is rotated about axis1402towards deformable band region1108, spring pin1404is configured to elongate as shown inFIG.14Bduring a first portion of the rotation. In some embodiments, elongation of spring pin1404can allow earpiece to rotate about 30 degrees from an initial position. Once spring pins1404reach their maximum length further rotation of earpieces1104about axes1402results in cable1302being pulled, which causes deformable band region1108to change from an arched geometry to a flat geometry as shown inFIG.14C. The delayed pulling motion changes the angle from which cable1302is initially pulled. The changed initial angle can make it less likely for cable1302to bind when transitioning headphones1400from the arched state to the flattened state.

FIGS.15A-15Fshow various views of headband assembly1500from different angles and in different states. Headband assembly1500has a bi-stable configuration that accommodates transitioning between flattened and arched states. FIGS.15A-15C depict headband assembly1500in an arched state. Bi-stable wires1502and1504are depicted within a flexible headband housing1506. Headband housing can be configured to change shape to accommodate at least the flattened and arched states. Bi-stable wires1502and1504extend from one end of headband housing1506to another and are configured to apply a clamping force through earpieces attached to opposing ends of headband assembly1500to a user's head to keep an associated pair of headphone securely in place during use.FIG.15Cin particular shows how headband housing1506can be formed from multiple hollow links1508, which can be hinged together and cooperatively form a cavity within which bi-stable wires1502are able to transition between configurations corresponding to the arched and flattened states. Because links1508are only hinged on one side, the links are only able to move to the arched state in one direction. This helps avoid the unfortunate situation where headband assembly1500is bent the wrong direction, thereby position the earpieces in the wrong direction.

FIGS.15D-15Fshow headband assembly in a flattened state. Because the ends of bi-stable wires1502and1504have passed an over-center point where the ends of wires1502and1504are higher than a central portion of bi-stable wires1502and1504, the bi-stable wires1502now help keep headband assembly1500in the flattened state. In some embodiments, bi-stable wires1502can also be used to carry signals and/or power through headband assembly1500from one earpiece to another.

FIGS.16A-16Bshow headband assembly1600in folded and arched states.FIG.16Ashows headband assembly1600in the arched state. Headband assembly, similarly to the embodiment shown inFIGS.15C and15Fincludes multiple hollow links1602that cooperatively form a flexible headband housing that define an interior volume. Passive linkage hinge1604can be positioned within a central portion of the interior volume and link bi-stable elements1606together.FIG.16Ashows bi-stable elements1606and16008in arched configurations that resist forces acting to squeeze opposing sides of headband assembly1600. Once opposing sides of headband assembly1600are pushed together, in the directions indicated by arrows1610and1612, with enough force to overcome the resistance forces generated by bi-stable elements1606and1608, headband assembly1600can transition from the arched state depicted inFIG.16Ato the folded state depicted inFIG.16B. Passive linkage hinge1604accommodates headphone assembly1600being folding around a central region1614of headband assembly1600.FIG.16Bshows how passive linkage hinge1604bends to accommodate the folded state of headband assembly1600. Bi-stable elements1606and1608are shown configured in folded configurations in order to bias the opposing sides of headband assembly1600toward one another, thereby opposing an inadvertent change in state. The folded configuration, depicted inFIG.16B, has the benefit of taking up a substantially smaller amount of space by allowing the open area defined by headband assembly1600for accommodating the head of a user to be collapsed so that headband assembly1600can take up less space when not in active use.

FIGS.17-18show various views of foldable headphones1700. In particular,FIG.17shows a top view of headphones1700in a folded state. Headband1702, which extends between earpieces1704and1706, includes wires1708and springs1710. In the depicted folded state, wires1708and spring1710are straight and in a relaxed state or neutral state.FIG.18shows a side view of headphones1700in an arched state. Headphones1700can be transitioned from the folded state depicted inFIG.17to the arched state depicted inFIG.18by rotating earpieces1704and1706away from headband1702. Earpieces1704and1706each include an over-center mechanism1802that applies tension to the ends of wires1708to keep wires1708in tension in order to maintain an arched state of headband1702. Wires1708help maintain the shape of headband1702by exerting forces at multiple locations along springs1710through wire guides1804, which are distributed at regular intervals along headband1702.

Telescoping Stem Assembly

FIG.19shows one side of a headband housing1902as well as telescoping member1904extending from the end of headband housing1902. Headband housing1902can be configured to accommodate telescoping motion of telescoping member1904. Headband housing1902defines multiple channels1906, which help guide spring fingers1908associated with telescoping member1904as telescoping member1904slides into and out of lower headband housing1902.FIG.19also depicts a portion of synchronization cable1910visible through channel1906and coiled within headband housing1902. The coiled configuration of synchronization cable1910allows synchronization cable1910to accommodate the changes in length caused by telescoping of telescoping member1904relative to headband housing1902.

FIG.20Ashows an exploded view of the side of headband housing1902depicted inFIG.19. In particular, headband housing1902is depicted including upper housing component2002and lower housing component2004. Lower housing component2004is configured to receive telescoping member1904. Lower housing component2004is depicted defining multiple channels1906and an annular bushing2006is disposed within one end of lower housing component2004and configured to control the motion of telescoping member1904relative to lower housing component2004by generating friction during movement of telescoping member1904.FIG.20Aalso depicts spring member2008as a single piece that includes multiple spring fingers2010configured to engage channels1906.

FIG.20Bshows a cross-sectional view of a first end of lower housing component2004in accordance with section line F-F. Lower housing component2004is depicted engaged with telescoping member1810and bushing2012is positioned within telescoping member1810. One of spring fingers2008is shown engaged within channel1906of lower housing component2004. In some embodiments, channel1906does not extend entirely through a wall of lower housing component2004as depicted inFIG.20C. This allows spring finger2008to be engaged within channel1906without it being cosmetically visible from an exterior of lower housing component2004.

FIG.20Cshows a cross-sectional view of a second end of lower housing component2004in accordance with section line G-G. The second end of lower housing component2004is depicted engaged with upper housing component2002. Synchronization cable1910is shown extending through an opening defined by both upper housing component2002and lower housing component2004.

FIG.20Dshows a perspective view of bushing2006, which defines multiple finger channels2012spaced radially around an interior-facing surface of bushing2006. Finger channels2012can be configured to align spring fingers2010with finger channels2012of lower housing component2004.

FIG.21Ashows a perspective view of spring member2014and one end of telescoping member1810. As depicted, spring member2014includes three spring fingers2008. Each of spring fingers2008includes a locking feature2102configured to prevent disengagement of spring member2014from telescoping member1810. Telescoping member1810defines a set of corresponding openings2104and2106divided by a bridging member2108. When spring fingers2008are engaged within openings2104a length of opening2104allows each of spring fingers2008to be deflected through openings2104so that telescoping member1810can be inserted into lower housing component2004.

FIG.21Bshows spring fingers2008engaged within openings2104andFIG.21Cshows spring fingers2008engaged within openings2106. When locking features2102are engaged within openings2106, spring member2014cannot be removed and remain engaged within channels1906. Furthermore, bridging members2108prevent spring fingers2008from deflecting any farther into an interior volume2110defined by telescoping member1810. This keeps protruding portions of spring fingers2008securely engaged within corresponding channels1906. In some embodiments, spring member2014can be shifted from the position depicted inFIG.21Bby pulling back on telescoping member1810once spring fingers2008are engaged within channels1906. In this way, spring fingers2008can be shifted from openings2104into openings2106.

FIGS.21D-21Gshow various locking mechanisms positioned at an opening defined by lower housing component2004through which telescoping member1810extends.FIGS.21D-21Eshow locking mechanism2112. InFIG.21D, when locking mechanism2112is turned in a first direction2114, telescoping member1810is able to be translated into or out of lower housing component2004, as indicated by two-sided arrow2116.FIG.21Eshows how subsequently turning locking mechanism2112in direction2118causes a position of telescoping member1810to be fixed relative to lower housing component2004.FIGS.21F-21Gshow locking mechanism2120.FIG.21Fshows how when locking mechanism2120is pulled away from lower housing component2004and toward telescoping member1810in direction2122, telescoping member1810is able to be translated into or out of lower housing component2004, as depicted by two-sided arrow2124.FIG.21Gshows how when locking mechanism2120is then pushed toward lower housing component2004in direction2126, a position of telescoping member1810relative to lower housing component2004is fixed.

Anti-Buckling Assembly

FIGS.22A-22Edepict various extended and contracted coil configurations for a portion of synchronization cable2010disposed within lower housing component2004.FIG.22Ashows a partial cross-sectional view of a portion of synchronization cable2010in a conventional helical coil configuration. Unfortunately, this configuration can be susceptible to individual loops2202shifting laterally when transitioning from the extended configuration2204to contracted configuration2206as depicted. Misalignment can lead to synchronization cable2010rubbing an interior of lower housing component2004and becoming frayed over time due to undesired friction inducing failure by fatigue of synchronization cable2010.

FIG.22Bshows how a cross-sectional shape of synchronization cable2010can be adjusted to include alignment features that help prevent loops2212of synchronization coil2010from becoming misaligned. In particular, opposing sides of loops2212can include alignment features having complementary geometries that help to self-align loops2212of synchronization coil2010when contracted, as depicted.

FIG.22Cshows how a cross-sectional shape of synchronization cable2010can be adjusted to include alignment features that help prevent loops2222of synchronization coil2010from becoming misaligned. In particular, opposing sides of loops2222can include alignment features taking the form of concave channels2224and convex ridges2226that help to self-align loops2212of synchronization coil2010when contracted, as depicted.

FIG.22Dshows how a cross-sectional shape of synchronization cable2010can be adjusted to include linking features that help prevent loops2232of synchronization coil2010from becoming misaligned. In particular, opposing sides of loops2232can include linking features taking the form of complementary hooks2234and convex ridges2226that help to self-align loops2212of synchronization coil2010when contracted, as depicted. The linking features also help to define a maximum amount of longitudinal extension of synchronization cable2010.

FIG.22Eshows another configuration in which synchronization cable2010can be prevented from becoming misaligned. By winding synchronization cable2010around a shaft2342, synchronization cable2010can be kept from becoming misaligned even though it is arranged as a helical coil. Shaft2342should be formed from a stiff material unlikely to go substantial amounts of bending, while also allowing for slight changes in curvature to accommodate motion of telescoping member1810. In some embodiments, shaft2242can be formed from NITINOL (a nickel-titanium alloy) wire.

FIG.23Ashows an exploded view of components associated with a data plug2302. In particular, data plug2302, which extends from one end of stem base2304is configured to engage a receptacle within telescoping member1810. Once engaged within the receptacle, data plug2302can be kept securely in place using threaded fastener2306, which is configured to engage a recess2308defined by a base portion of data plug2302through threaded opening2310. Seal rings2312can also be used to further secured data plug2302within telescoping member1810.FIG.23Bshows telescoping member1810fully assembly with threaded fastener2306fully engaged within threaded opening2310in order to keep data plug2302securely positioned.

FIG.23Cshows a cross-sectional view of telescoping member1810in accordance with section line H-H ofFIG.23B. In particular,FIG.23Cshows one end of data plug2302engaged within plug receptacle2314.FIG.23Calso shows how threaded fastener cooperates with recess2308to keep data plug2302secured in place. A position of seal rings2312is also shown relative to data plug2302. It should be noted that in some embodiments data plug2302could be omitted in lieu of a cable terminating in a board to board connect that engages a printed circuit board within an associated earpiece of the headphones.

FIG.23Dshows a perspective view of a portion of data plug2302. In particular, the body of data plug2302has a stepped geometry and defines multiple glue channels2316spaced at a regular interval. In some embodiments, glue channels2316can be laser cut into an exterior side surface of the body of data plug2302.FIG.23Eshows a cross-sectional side view of the portion of data plug2302and depicts multiple glue channels2316positioned on opposing sides of the body of data plug2302.

FIG.23Fshows data plug2302glued to stem base2304, which is in turn positioned within a recess2318defined by earpiece2320.FIG.23Gshows a cross-sectional view of data plug2302disposed within a recess defined by stem base2304, which is in turn positioned within recess2318of earpiece2320.FIG.23Gcorresponds to section line I-I as depicted inFIG.23Fand also shows how data plug2302is adhered to stem base2304by an adhesive layer2322. A strength of a bond formed by adhesive layer2322between stem base2304and the body of data plug2302is substantially increased due to adhesive layer2322being able to engage glue channels2316. In some embodiments, an interior-facing surface of stem base2304can also include glue channels similar to glue channels2316for even greater adhesion. In some embodiments, one or both of the surfaces contacting adhesive layer2322can be roughened, thereby increasing the surface energy of the surfaces and improving the strength of a resulting adhesive coupling.FIG.23Galso depicts a data synchronization cable2324extending through channels defined by both data plug2302and stem base2304.

Earpad Configurations and Optimization

FIG.24Ashows perspective views of earpiece2402and earpad2404. Earpad2404is shown having a planar shape illustrating how the side of a user's head2406is anything but flat. One reason most earpads are quite robust in thickness is to accommodate the cranial contours of the side of a user's head. The dashed arrows depicted inFIG.24Aillustrate the variance in distance earpads need to overcome to conform with the cranial contours.

FIG.24Bshows how earpieces2412and2414of headphones2410can have thin earpads2416without sacrificing user comfort. Earpads2416can include a flexible substrate that allows for a predetermined amount of flexure to accommodate variations in cranial contours. Earpads2416can be coupled to earpiece yokes2418with two posts2420positioned in locations corresponding to normally low points on a user's head. In the depicted configuration, the portions of earpads2416encountering protruding cranial contours can bend back to prevent pressure points on a user's head. In this way, a substantial amount of weight and material cost can be saved since thinner pads can be utilized without sacrificing user comfort.

FIG.24Cshows how posts2420couple flexible substrate2422to earpiece yokes2418. Flexible substrate2422is formed from a substrate having a flexibility sufficient to allow for deformation of earpads2416mounted to flexible substrate2422. It should be noted that many components have been removed from earpiece2414inFIG.24Cto clearly show how flexible substrate2422is connected to earpiece yoke2418.FIG.24Dshows earpiece2414and an axis of rotation2424about which earpad2416is configured to bend to accommodate cranial contours of a user's head. Axis of rotation2424is defined by the locations at which posts2420attach to a rear-facing surface of flexible substrate2422and consequently earpad2416.

FIG.24E-24Hdepict another earpiece in a configuration designed to account for cranial contours of a user's head.FIG.24Eshows a side view of earpiece2430. Earpiece2430includes convex input panel2432, earpiece housing2434and earpad assembly2436. Convex input panel2432can be affixed to one side of earpiece housing2434and include sensors for receiving touch inputs to headphones associated with the earpiece.FIG.24Ealso depicts compressible earpad2438of earpad assembly2436. Compressible earpad2438can be formed from foam and have a substantially uniform thickness. By bending compressible earpad2438as depicted into a curved geometry a user-facing surface of earpad assembly2436can be shaped to match cranial contours of a user's head.

FIG.24Fshows a cross-sectional view of earpiece2430as well as a shape of a cavity2440for accommodating an ear2442. With headphones designs that are not configured to accommodating placing earpiece2430over either ear, speaker assembly2444can protrude into cavity2440without affecting the amount of space available for ear2442. In some embodiments, pushing speaker assembly2444forward in this manner can reduce the overall size of earpiece2430.FIG.24Falso demonstrates how an undercut geometry of earpad2438allows earpiece2430to seal around a portion of the user's head closer to ear2442, thereby reducing the length of a perimeter of the portion earpad assembly2436contacting the head of the user. In some embodiments, this can improve passive noise isolation. Earpad2438can be covered by textile material2446to provide a pleasant feel to the portion of earpad assembly2436contacting the user. In some embodiments, various treatments can be applied to textile material2446to improve the acoustic isolation provided by textile material2446. For example, a heat treatment could be applied to at least the portion of textile material2446most likely to contact the user's head in order to reduce a pore size of textile material2446, thereby boosting acoustic resistance.

FIG.24Gshows a perspective view of earpiece2430and more clearly illustrates the varying curvature of earpad assembly2436around a periphery of earpad assembly2436. In particular, region2448of earpad assembly2436is configured to contact a portion of a user's head beneath and to the rear of the ear where the head starts to slope back toward the neck. For this reason, region2448protrudes substantially farther out from earpiece2430than any other portion of earpad assembly2436. To a somewhat lesser extent region2450of earpad assembly2436also protrudes away from earpiece2430to accommodate another low spot on a user's head generally located forward and slightly above the user's ear.

FIGS.25A-25Cshow various views of another earpad configuration2500formed from multiple layers of material.FIG.25Ashows an exploded view of earpad configuration2500that includes three different component layers, namely cushion2502, compliant structural layer2504and textile layer2506. In some embodiments, cushion2502can be formed from foam and shaped during a machining process, which will be described in greater detail below. Compliant structural layer2504can help define a shape of a periphery of cushion2502, while giving an exterior of the earpiece an amount of compliance. In some embodiments, compliant structural layer2504can be formed from an ethylene-vinyl acetate rubber blend. Textile layer2506can be formed from a sheet of fabric and includes multiple distinct regions2508and2510. Region2510, which makes up a majority of the fabric in direct contact with a user's head, can be heat treated to seal any gaps in the fabric in order to improve passive acoustic isolation. This can be particularly important with headphones with an active noise cancelling system as improved passive acoustic isolation reduces the amount of noise needing to be cancelled out by the active noise cancelling system. In some embodiments, region2510can be heat-treated so that its porosity is substantially smaller than the porosity of regions2508. Lower porosity textile materials are generally more effective at providing passive noise attenuation.

FIG.25Bshows how foam cushion2502along with compliant structural layer2504and textile layer2506can be formed around an electronics housing component2512defining an interior volume2514configured to accommodate various electrical components supporting playback of media files received by headphones associated with earpad configuration2500.FIG.25Balso illustrates the importance of aligning textile layer2506with openings defined by electronics housing component2512, since opening2516of textile layer2506is configured to align with opening2518of electronics housing component2512to accommodate an I/O port or input control. Furthermore, opening2520may also need to be aligned with post2522of housing component2512.

FIG.25Cshows a cross-sectional side view of earpad configuration2500. In particular,FIG.25Cshows how textile layer2506includes two regions2508positioned on different sides of heat-treated region2510and how compliant structural layer2504extends beneath region2510of textile layer2506.FIG.25Dshows how heat-treated regions2510of textile layer2506are in direct contact with the side of a user's head when the headphones are in active use. In this way, an effective barrier is formed by heat-treated regions2510against the passage of audio waves between the user's head and earpad configuration2500, which would generally not be considered viable for a headphones using textile material to cover the earpads. While region2510is shown extending entirely across a surface contacting a user's face it should be understood that in certain embodiments, only a portion of the textile fabric contacting a user has undergone the heat treatment.

FIGS.26A-26Bshow perspective views of earpad2602, which can be formed from a conformable material such as open cell foam. Conventional foam pads for headphones are formed from rectangular blocks and if formed using machining methods at all would be formed by a stamping process. By machining earpads2602from a larger block a precise three-dimensional shape can be achieved. Machining is also superior over performing injection since while these types of processes could include a mold to achieve a desired shape the surface consistency often is materially different due to the heating processes that take place during the molding process. For at least these reasons, performance of a machined foam as an earpad cushion is substantially better than the alternatives since it allows for a customized responsiveness to pressure and reducing the overall weight of each earpad cushion by allowing for unneeded portions of the foam to be easily cut away. As depicted, earpad2602has a gradual sloping geometry on both sides, as depicted byFIGS.26A-26B, that give earpad2602an undercut geometry helping to establish a desired firmness of earpad2602.

FIG.26C-26Gshow various manufacturing operations for forming an earpad from a block of foam.FIG.26Cshows open cell foam block2604once it is formed by an extrusion or molding process. InFIG.26D, profile cutter2606and ball end mill2608are depicted forming opposing sides of earpad2602from foam block2604. In some embodiments, the cutting and milling process can be made more exact by first soaking foam block2610in water as shown inFIG.26Eand then freezing foam block as shown inFIG.26F. In some embodiments, when profile cutter2606and ball end mill2608are applied to frozen foam block2610the machining operations can be a little more accurate since the foam material is less likely to move and deform under an amount of pressure applied by the machining tools. While the annular earpad is depicted having a substantially rectangular cross-sectional geometry, the CNC process allows for a much broader variety of shapes. For example, tear-drop, circular, square, elliptical, polygonal and other cross-sectional geometries could be realized by varying the machining operations performed by profile cutter2606and ball end mill2608. Non-euclidian surface shapes such as spline geometries are also fully capable realization using the aforementioned machining technique.

Speaker Assembly

FIG.27Ashows a cross-sectional side view of an exemplary acoustic configuration within earpiece2700that could be applied with any of the previously described earpieces. The acoustic configuration includes speaker assembly2702, which includes diaphragm2704and electrically conductive coil2706, which is configured to receive electrical current for generating a shifting magnetic field that interacts with a magnetic field emitted by permanent magnets2708and2710, which causes diaphragm2704to oscillate and generate audio waves that exit earpiece assembly through perforated wall2709. In some embodiments, perforated wall2709can include an array of capacitive sensors as depicted inFIGS.9A-9B. A hole can be drilled through a central region of permanent magnet2708to define an opening2712that puts a rear volume of air behind diaphragm2704in fluid communication with interior volume2714through mesh layer2716, thereby increasing the effective size of the back volume of speaker assembly2702. Interior volume2714extends all the way to air vent2718. Air vent2718can be configured to further increase an effective size of the rear volume of speaker assembly2702. For example, air vent2718can act as a bass reflex vent for augmenting performance of speaker assembly2702. The rear volume of speaker assembly2702can be further defined by speaker frame member2720and input panel2722. In some embodiments, input panel2722can be separated from speaker frame member2720by about 1 mm. Speaker frame member2720defines an opening2724that allows audio waves to travel through additional ducting that routes the rear volume. Glue channel2726is defined by protrusions2728of speaker frame member2720.

FIG.27Bshows an exterior of earpiece2700with input panel2722removed to illustrate the shape and size of the interior volume associated with speaker assembly2702. As depicted, a central portion of earpiece2700includes permanent magnets2708and2710. Speaker frame member2720includes a recessed region that defines interior volume2714. Interior volume2714can have a width of about 20 mm and a height of about 1 mm as depicted inFIG.27A. At the end of interior volume2714is opening2724defined by speaker frame member2720, which is configured to allow the back volume to continue beneath glue channel2726and extend to air vent2718, which leads out of earpiece2700.

FIG.27Cshows a cross-sectional view of a microphone mounted within earpiece2700. In some embodiments, microphone2730is secured across an opening3732defined by speaker frame member2720. Opening3732is offset from microphone intake vent2734, preventing a user from seeing opening2732from the exterior of earpiece2700. In addition to providing a cosmetic improvement, this offset opening configuration also tends to reduce the occurrence of microphone2730picking up noise from air passing quickly by microphone intake vent2734.

FIG.28shows earpiece2700having input panel2720, which can form an exterior facing surface of earpiece2700. A touch sensitive region can be established by touch sensor2802, which can take the form of a flexible substrate affixed to an interior facing surface of input panel2720. The flexible substrate can define multiple notches2804, which function as strain relief features allowing the flexible substrate to conform to a concave shape of the interior-facing surface of input panel2720. Passive radiator2806is depicted adjacent to touch sensor2802and also affixed to the interior-facing surface of radio transparent input panel2720. Passive radiator2806can be formed from a stamped sheet of metal or be formed along a flexible printed circuit. This configuration prevents interference between passive radiator2806and touch sensor2802. Passive radiator2806can cooperate with internal antenna2808, which is also positioned within earpiece2700, to improve wireless performance.

Distributed Battery Configuration

FIGS.29A-29Bshow perspective and cross-sectional views of an outline of earpiece2900illustrating a position of distributed battery assemblies2902and2904within earpiece2900. In particular,FIG.29Ashows how battery assemblies2902and2904can be positioned on opposing sides of a housing of earpiece2900.FIG.29Bshows a cross-sectional view of earpiece2900in accordance with section line J-J. Battery assemblies2902and2904can also be tilted diagonally with respect to an ear cavity defined by earpiece2900, as depicted inFIG.29B, to maximize a size of an ear cavity2906defined by earpiece2900.FIG.29Cshows how more than two discrete battery assemblies can be incorporated into a single earpiece housing. For example, three, four, five or six discrete battery assemblies could be distributed along a periphery of earpiece2900as is shown inFIG.29C. In some embodiments, and as is shown inFIG.29Cbattery assemblies2908-2914have a curvature that follows a curvature of an outer periphery of the earpiece housing and more generally the space available within the earpiece housing. Each of the discrete battery assemblies can have their own input and output terminals configured to support operation of various components within earpiece2900.

FIG.30Ashows headphones3000, which include earpieces3002and3004joined together by headband3006. A central portion of headband3006has been omitted to focus on components within earpieces3002and3004. In particular, earpieces3002and3004can include a mix of Hall Effect sensors and permanent magnets. As depicted, earpiece3002includes permanent magnet3008and Hall Effect sensor3010. Permanent magnet3008generates a magnetic field extending away from earpiece3002with a South polarity. Earpiece3004includes Hall Effect sensor3012and permanent magnet3014. In the depicted configuration, permanent magnet3008is positioned to output a magnetic field sufficiently strong to saturate Hall Effect sensor3012. Sensor readings from Hall Effect sensor3012can be sufficient to cue headphones3000that headphones3000are not being actively used and could enter into an energy savings mode. In some embodiments, this configuration could also cue headphones3000that headphones3000were being positioned within a case and should enter a lower power mode of operation to conserve battery power. Flipping earpieces3002and3004180 degrees each would result in a magnetic field emitted by permanent magnet3014saturating Hall Effect Sensor3010, which would also allow the device to enter a low power mode. In some embodiments, it could be desirable to use an accelerometer sensor within one or both of earpieces3002to confirm that earpieces3002and3004are facing toward the ground before entering a lower power state as a user could desire to set earpieces3002and3004facing upward to operate headphones in an off the head configuration and in such a case audio playback should be continued.

FIG.30Bshows an exemplary carrying/storage case3016well suited for use with circumaural and supra-aural headphones designs. Case3016includes a recess3018to accommodate a headband assembly and two earpieces. The portions of recess3018that accommodate the earpieces can include protrusions3020and3022, which fill recesses of earpieces sized to accommodate the ear of a user.FIG.30Cshows headphones3000positioned within recess3018andFIG.30Dshows a cross-sectional view of earpiece3002in accordance with section line K-K ofFIG.30C.FIG.30Dshows how protrusion3020include capacitive elements3024arranged along an upward-facing surface of protrusion3020in a predefined pattern. Consequently, when headphones3000are placed within case3016and capacitive sensors3026sense capacitive elements in that predefined pattern headphones3000can be configured to shut down or go into a lower power mode to conserve power.

FIG.30Eshows carrying case3016with headphones3000positioned therein. Headphones3000are depicted including ambient light sensor3028. In some embodiments, input from ambient light sensor3028can be used to determine when case3016is closed with headphones disposed within case3016. Similarly, when sensor readings from ambient light sensor3028indicate an amount of light consistent with carrying case3016opening, a processor within headphones3000can determine that carrying case3016has been opened. In some embodiments, when other sensors aboard headphones3000indicate headphones3000are positioned within a recess defined by carrying case3016, the sensor data from ambient light source3028can be sufficient to determine when carrying case3016is open or closed. Examples of other sensors include the capacitive sensors discussed in the text describingFIGS.30B-30D. Other examples of sensors could take the form Hall Effect sensors3030disposed within earpieces3002and3004that could be configured to detect magnetic fields emitted by permanent magnets3032disposed within carrying case3016. In some embodiments, one or more of magnets3032can be configured to emit a magnetic field with one or more recognizable magnetic field characteristics. For example, the two depicted permanent magnets3032could have opposing polarities that interact with Hall Effect sensors3030. Furthermore, one or both of permanent magnets could have a particularly strong magnetic field or a customized magnetic field with a highly varied polarity. Inadvertently experiencing such a magnetic field outside the controlled environment of the case would be unlikely and consequently, headphones configured to enter a low power state in response would be unlikely to do so accidentally. This second set of sensor data provided by Hall Effect sensors3030could substantially reduce the incidence of sensor data from ambient light sensor3028mistakenly being correlated with case opening and closing events. The use of sensor readings from other types of sensors such as strain gauges, time of flight sensors and other headphone configuration sensors can also be used to make operating state determinations. Furthermore, depending on a determined operating state of headphones3000these sensors could be activated with varying frequency. For example, when carrying case3016is determined to be closed around headphones3000sensor readings can only be made at an infrequent rate, whereas in active use the sensors could operate more frequently.

Illuminated Button Assembly

FIGS.31A-31Bshow an illuminated button assembly3100suitable for use with the described headphones.FIG.31Ashows how illuminated button assembly3100includes button3102and illuminated window3104, which can be configured to identify an operating state of headphones. Button3102is electrically coupled with other components within headphones by flexible circuit3106. At least a portion of button assembly3100can be secured to a device housing by mounting bracket3108.FIG.31Bshows a rear view of illuminated button assembly3100, and how mounting bracket3108can be configured to receive fasteners3110to secure illuminated button assembly to a device housing.

FIGS.31C-31Dshow side views of illuminated button assembly3100in unactuated and actuated positions, respectively, within a device housing3111.FIG.31Cshows how illuminated window3104of button3102can have a tapered shape that directs light emitted by any one of multiple illumination elements3114. Illuminated window3104can also include securing features3112, which protrude laterally from illuminated window3104to prevent illuminated window3104from becoming disengaged from button3102. Illumination elements3114can be positioned proximate a rear-facing surface of illuminated window3104. Illumination elements3104can each take the form of a light emitting diode (LED) surface mounted to flexible circuit3106. In some embodiments, each of illumination elements3114can be configured to emit light of a different color, thereby allowing the light received by illuminated window3104to be changed to reflect a status or operating state of the device associated with illumination button assembly3100. In some embodiments, illumination elements3114could include red, yellow and blue colors. Selective illumination of two or more of the different colors at varying intensity levels could allow a great number of different colors to be generated informing the user of the illuminated button assembly of many different operating conditions.

FIG.31Dshows how actuation of button3102with force3115causes a portion of button3102to slide into an interior volume defined by housing3111. Because illumination elements3114are affixed directly to a rear surface of button3102, the amount of light projected through illumination window3104remains constant regardless of the amount of movement made by button3102. This differs from conventional buttons having illumination elements positioned on a printed circuit board that includes an electrical switch. Consequently, in the conventional configuration the amount of illumination increases during button actuation as the button gets closer to the illumination elements during actuation. It should be noted that in the design depicted inFIGS.31C-31D, electrical switch3116is affixed to a bracket3118to keep electrical switch3116in a fixed position. In this way, when a rear-facing surface of button3102comes in contact with electrical switch3116, bracket3118provides an amount of resistance sufficient to register the actuation. Electrical switch3116can take the form of a dome switch, which is also helpful in providing tactile feedback to a user of illumination button assembly3100.

FIG.31Eshows a perspective view of illuminated window3104. Illuminated window3104includes securing features3112protruding from a tapered body of illuminated window3104. It should be appreciated that laterally protruding securing features3112can take many forms. At minimum, securing features3112are engaged with a laterally oriented notch that prevents dislodgment of illuminated window3104from button3102. In some embodiments, illuminated window3104can insert molded into an opening defined by button3102. In this type of insert molding operation, the opening defined by button3102could determine the shape and size of illuminated window3104.

Removable Earpieces

FIGS.32A-32Bshow perspective views of a pivot assembly associated with a removable earpiece engaged by a stem base of a headphone band. In particular, pivot assembly3202is configured to accommodate rotation of the associated earpiece relative to the headphone band about axes of rotation3204and3206.FIG.32Adepicts stem base3208engaged and locked into place within pivot assembly3202. A distal end3210of stem base3208is locked in place by latch plate3212. In particular, latch plate3212includes walls that define an aperture3214that engages a neck of stem base3208to prevent inadvertent removal of stem base3208from pivot assembly3202.FIG.32Aalso shows a portion of earpiece housing3216that provides an opening accommodating switch mechanism3218. Switch mechanism3218is configured to allow stem base3208to be released from pivot assembly3202. Switch mechanism3218includes a protruding engagement member3220, which is configured to contact force translation member3222. In some embodiments, switch mechanism3218can be concealed beneath a removable earpad assembly.

FIG.32Bshows how a force3224exerted upon switch mechanism3218is applied to translation member3222by engaging member3220. The angled end of engagement member3220transmits force3224to a first post3226of force translation member3222, which in turn causes force translation member3222to rotate about axis of rotation3228. Axis of rotation3228is defined by a fastener3227, which pivotally couples one end of force translation member3222to an undepicted portion of earpiece housing3216. Rotation of force translation member3222about axis of rotation3228results in a second post3230applying a force3232to a wall of latch plate3212. Force3232applied to latch plate3212shifts latch plate3212laterally to align aperture3214with distal end3210of stem base3208. Once aperture3214is aligned with distal end3210of stem base3208a force3234can be applied to stem base3208that allows stem base3208to be removed from pivot assembly3202.

FIGS.33A-33Cshow different views of a latching mechanism3300of a pivot assembly.FIG.33Ashows how the pivot assembly includes latch body3302, which defines a channel along which latch plate3304is configured to slide. Latch body3302has a circular geometry that allows it to rotate with a stem base3306and its associated stem plug3308. Stem plug3308includes a contact region3310. Contact region3310can include multiple electrical contacts for interfacing with circuitry and electrical components disposed within the same earpiece as latching mechanism3300. In some embodiments, contact region3310includes a number of different electrical contacts, e.g., two, three or four different electrical contacts are possible electrical contact configurations. In some embodiments, both sides of stem plug3308can include contact regions that include multiple electrical contacts for interfacing with circuitry and electrical components of an earpiece. It should be noted that latching mechanism3300is generally positioned within an earpiece housing so that aperture3312is aligned with a stem opening defined by the earpiece housing to allow for insertion of stem base3306into both the earpiece housing and aperture3312of latching mechanism3300.

FIG.33Aalso shows how latch plate3304defines an asymmetric aperture3312. InFIG.33A, latch plate3304is in a latched position where a smaller portion of aperture3312is engaged with a narrow neck portion separating stem plug3308from the rest of stem base3306. By engaging the narrow neck portion with a smaller portion of aperture3312, latch plate3304can prevent stem base3306being removed from latching mechanism3300. Latching mechanism also includes latch lever3314, which is configured to rotate about axis of rotation3317. Torsion spring3316is coupled to latch lever3314and opposes rotation of latch lever3314. A first arm3318engages a portion of an earpiece housing (not depicted) and a second arm3320engages a portion of latch lever3314. When a force3322latch lever3314is applied to latch lever3314it rotates counter-clockwise and exerts a force upon latch plate3304sufficient to cause latch plate3304to slide laterally within latch body3302. When force3322is released retaining spring3324is configured to exert a force on post3326of latch plate3304to return latch plate3304to the position depicted inFIG.33A. It should be noted that while stem plug3308is depicted as being exposed, this is for descriptive purpose only and in some embodiments a plug receptacle configured to mate with stem plug3308can be attached to latching mechanism3300by one or more of fasteners3327.

FIGS.33B-33Cshow bottom views of latching mechanism3300in locked and unlocked positions. A dotted outline is provided and shows the size and shape of an exemplary pivot mechanism suitable for carrying latching mechanism3300.FIG.33Bshows a switch mechanism3328that can slide along a channel or groove defined by an associated earpiece housing. Switch mechanism can take the form of a horizontal slider switch that allows for engagement and rotation of latch lever3314.FIG.33Cshows how rotation of latch lever3314displaces latch plate3304laterally such that a larger portion of aperture3312is aligned with stem plug3308, thereby allowing removal of stem plug3308from latching mechanism3300.FIG.33Calso shows how retaining spring3324is able to deform to accommodate the lateral movement of latch plate3304when switch mechanism3328is actuated. When pressure is released from switch mechanism3328, retaining spring3324and torsion spring3316cooperatively bias switch mechanism3328back to its starting position as depicted inFIG.33B. In some embodiments, it may be desirable to position switch mechanism within a channel of the earpiece housing located such that the switch mechanism is concealed by a removable earpad assembly. For example, in some embodiments, the earpad assembly can be coupled to the earpiece housing by magnets or a series of snaps.

Telescoping Stem Mechanism

FIG.34Ashows headphones3400which includes earpieces3402and3404mechanically coupled together by headband assembly3406. Headband assembly includes signal cable3408, which electrically couples electrical components within earpieces3402and3404together. Portions of signal cable3408near its opposing ends are arranged in coils3410, which are configured to expand and contract to accommodate increases and decreases in the size of headband assembly3406. In some embodiments, it can be helpful to include mechanisms that help keep coils3410from tangling after undergoing multiple headband assembly telescoping operations.

FIG.34Bshows a close up view of a stem region3412of headband assembly3406. In some embodiments, stem region3412is made up of multiple different housing components. As depicted, stem region3412includes a portion of an upper housing component3414, lower housing component3416and telescoping component3418and stem base3420. In some embodiments, telescoping component3418and stem base3420can be welded together or otherwise permanently coupled together to form a hollow stem defining a channel that accommodates the passage of a coiled portion of cable3408. Telescoping component3418is shown retracted entirely within an interior volume defined by lower housing component3416. In this position, coils3410of signal cable3408are compressed together to accommodate the shortened length of stem region3412. A distal end of telescoping component3418includes a funnel element3422configured to help guide signal cable3408back into the depicted configuration of coils3410. Directly behind funnel element3422is a first stabilizing element3424. First stabilizing element has an outer diameter that is about equal to an inner diameter of lower housing component3416. This helps create a slight interference fit between first stabilizing element3424and lower housing component3416that helps keep the distal end of telescoping component3418centered within the interior volume defined by lower housing component3416. Directly behind first stabilizing element3424is first bearing element3426, which has a slightly smaller diameter than first stabilizing element3424but is formed of a harder, less resilient material than first stabilizing element3424. In this way, first bearing element3426can set a hard stop that prevents telescoping component from getting too close to an interior of the interior-facing surface of the walls making up lower housing component3416.

FIG.34Balso shows how a distal end of lower housing component3416includes a second bearing element3428and a second stabilizing element3430. Second stabilizing element has a smaller inner diameter than second bearing element3428, allowing second stabilizing element3430to help bias telescoping component3418toward a central portion of lower housing component3416while second bearing element3428creates a hard stop that keeps the rest of telescoping component3418out of direct contact with other portions of lower housing component3416. In this way, both the distal end and proximal ends of telescoping component3418are constrained. As telescoping component3418telescopes out of lower housing component these constraints help establish a desired amount of friction between the two components and prevent any binding or scraping that could result in undesirable operation or even damage of headband assembly3406. It should also be noted thatFIG.34Balso depicts stem plug3308positioned at a distal end of stem base3420. Stem plug3308can include two or more electrical contacts for interfacing/electrically coupling with circuitry and electrical components of earpiece3402or3404.

FIG.34Cshows a close up view of the distal end of telescoping component3418. In particular, funnel element3422is depicted having tapered protrusions that extend past the end of telescoping component3418. The tapered geometry of the protrusions helps align adjacent coils3410as they pass through funnel element3422and into telescoping component3418. As depicted, some of adjacent coils are misaligned. This misalignment can be corrected at least in part by the tapered geometry of funnel element3422. First stabilizing element3424is depicted immediately behind funnel element3422. First stabilizing element3424can include a series of axially aligned ribs that interface with and cause minor amounts of friction with interior-facing surfaces of lower housing component3416. In some embodiments, a layer of lubricant can be applied within lower housing component3416in order to reduce an amount of resistance generated by friction between the components. It should be noted that a number, thickness and spacing between the axially aligned ridges can be tuned to achieve a desired amount of friction between the components. First stabilizing element3424and funnel element3422both includes radial stabilization elements3432and3434that protrude radially from telescoping component3418to engage an axially aligned channel defined by interior-facing surfaces of lower housing component3416. By engaging this channel, radial stabilization elements3432and3434are able to prevent unwanted rotation of telescoping component3418relative to lower housing component3416.

FIG.34Calso shows first bearing element3426, which can also include a radial stabilizing element3436. In some embodiments, radial stabilizing element3436can also include a spring that helps keep telescoping component3418stabilized within lower housing component3416. It should be noted that first bearing element has an outer diameter that is slightly smaller than first stabilizing element3424and a slightly larger outer diameter than the rest of telescoping component3418, which can take the form of a hollow tube formed from aluminum, stainless steel or other robust lightweight materials.

FIG.34Dshows a cross-sectional view of a distal end of telescoping component3418in accordance with section line L-L as depicted inFIG.34B. In particular, lower housing component3416is shown defining multiple axially aligned channels configured to accommodate radial stabilization elements3432. As depicted, telescoping component also include ridges that support a portion of and provide a robust support for radial stabilization elements3432.FIG.34Dalso depicts how the ridges of first stabilization element3424define multiple channels that reduce the total surface area contact between first stabilization element3424and an interior-facing surface of lower housing component3416.

FIG.34Eshows a cross-sectional view of a distal end of lower housing component3416in accordance with section line M-M as depicted inFIG.34B. In particular, lower housing component3416is shown having a wider diameter at its distal end than the rest of the length of lower housing component3416. This wider diameter end of lower housing component3416allows for second stabilizing element3430to have a greater amount of compliant material positioned between telescoping component3418and lower housing component3416. This larger amount of material can beneficially provide a greater amount of compliance if desired. By rapidly reducing the cross-sectional area of lower housing component3416, the large diameter of second stabilizing element3430is prevented from being pushed too far into lower housing component during use or assembly. Furthermore, an amount of friction between second stabilizing element3430and telescoping component3418can be reduced or tuned by the number and size of the channels3440formed by ridges arranged along an inner diameter of stabilizing element3430.

FIGS.34F-34Hshow a number of alternative embodiments that allow for a larger or smaller amount of play to be established between lower housing component3416and telescoping component3418. InFIG.34F, wedge-shaped radial stabilization elements can be used to counter play in all degrees of freedom. A small gap can be established between radial stabilization elements3442and telescoping component3418. The small gap can be used to create extra play in a single direction to add additional play needed to accommodate any differences in the curvature of lower housing component3416and telescoping component3418. In such a configuration a radial location of radial stabilization elements3442and its supporting channels correspond to a direction of curvature of lower housing component3416and telescoping component3418. The configuration shown inFIG.34Gaccommodates a certain amount of rotation of telescoping component3418relative to lower housing component3416and also accommodates movement in the X-axis. The configuration shown inFIG.34Hshows how telescoping component3418can be constrained both radially and in the X-axis direction allowing movement of telescoping component3418only in the Y-axis.

FIGS.34I-34Jshow telescoping component3418disposed within an interior volume defined by lower housing component3416. InFIG.34I, lower housing component includes multiple compliant members3444arranged at a regular interval along an interior surface of lower housing component3416. Compliant members3444could take many forms including compliant spring members that while allowing for displacement do not unduly add friction during movement of telescoping component3418. InFIG.34J, telescoping component3418is shown compressing a stabilization element3446until it is stopped when it contacts bearing element3448which can be constructed from material that is substantially more rigid than stabilization element3446. In some embodiments, stabilization element3446can be formed from a material such as an FKM (fluoroelastomers) while bearing element3448can be formed from a material such as PEEK (polyether ether ketone).

While each of the aforementioned improvements has been discussed in isolation it should be appreciated that any of the aforementioned improvements can be combined. For example, the synchronized telescoping earpieces can be combined with the low spring-rate band embodiments. Similarly, off-center pivoting earpiece designs can be combined with the deformable form-factor headphones designs. In some embodiments, each type of improvement can be combined together to produce headphones with the described advantages from the incorporated types of improvements.

The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data, which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

The following paragraphs list numbered claims describing embodiments disclosed herein.

1. An earpiece, comprising: a housing defining a cavity for accommodating an ear of a user; an active noise cancelling system; an annular earpad coupled to the housing; and a textile layer wrapped around the annular earpad, the textile layer including a first region and a second region, the first region having a lower porosity than the second region of the textile layer.

2. The earpiece as recited in claim1, wherein the textile layer is formed from a single layer of material and the porosity of the first region is lowered by applying a heat treatment to the first region.

3. The earpiece as recited in claim1, wherein the annular earpad has an undercut geometry.

4. The earpiece as recited in claim1, wherein the annular earpad has an asymmetric geometry that conforms with cranial contours of a head of the user.

5. The earpiece as recited in claim1, wherein the active noise cancelling system comprises a microphone disposed within the earpiece, and wherein the housing defines an audio entrance opening for the microphone that is laterally offset from the microphone.

6. The earpiece as recited in claim5, wherein the housing comprises an aluminum housing component that defines the audio entrance opening.

7. The earpiece as recited in claim1, wherein the cavity has an undercut geometry that is cooperatively defined by the annular earpad and the housing.

8. A portable listening device, comprising: an earpiece housing defining a cavity for accommodating an ear of a user; a headband assembly coupled to the earpiece housing; an active noise cancelling system; an earpad assembly coupled to the earpiece housing; and a textile layer wrapped around the earpad assembly, the textile layer including a first region and a second region, the first region having a lower porosity than the second region of the textile layer.

9. The portable listening device as recited in claim8, wherein the first region has an annular geometry positioned over a portion of the textile layer positioned along a periphery of the earpad assembly to improve passive noise attenuation characteristics of the earpad.

10. The portable listening device as recited in claim8, wherein the earpad assembly comprises an annular earpad formed by performing a subtractive machining operation on an open cell foam block.

11. The portable listening device as recited in claim10, wherein the annular earpad has a non-rectangular cross-sectional geometry.

12. The portable listening device as recited in claim10, wherein the earpad assembly comprises a compliant structural member that couples the annular earpad to the earpiece housing.

13. A portable listening device, comprising: a first earpiece; a second earpiece; a headband assembly coupling the first earpiece to the second earpiece; a magnetic field sensor assembly disposed within the first earpiece and configured to measure an amount of rotation of the first earpiece relative to the headband assembly; and a processor configured to change an operating state of the portable listening device based on the amount of rotation measured by the magnetic field sensor assembly.

14. The portable listening device as recited in claim13, wherein at least a portion of the magnetic field sensor assembly is coupled to a portion of a stem of the headband assembly and disposed within the first earpiece.

15. The portable listening device as recited in claim13, wherein the processor is configured to change the operating state when the measured amount of rotation exceeds a predetermined threshold.

16. The portable listening device as recited in claim14, wherein the magnetic field sensor assembly comprises: first and second permanent magnets coupled to the portion of the stem; and a magnetic field sensor coupled to a housing of the first earpiece.

17. The portable listening device as recited in claim14, wherein the magnetic field sensor assembly comprises: a magnetic field sensor coupled to the portion of the stem; and first and second permanent magnets coupled to a housing of the first earpiece.

18. The portable listening device as recited in claim16, wherein a polarity of a first magnetic field emitted by the first permanent magnet is oriented in a first direction and a polarity of a second magnetic field emitted by the second permanent magnet is oriented in a second direction opposite the first direction.

19. The portable listening device as recited in claim13, wherein the processor is configured to control the operating state based on the amount of rotation measured by the magnetic field sensor assembly, the magnetic field sensor assembly being configured to identify three or more different locations of the headband assembly relative to the first earpiece.

20. The portable listening device as recited in claim15, wherein the headphones enter a low power state when the amount of rotation detected by the magnetic field sensors assembly is below the predetermined threshold.

21. The portable listening device as recited in claim13, further comprising an optical sensor assembly disposed within the first earpiece and configured to direct light waves at an ear of a user, wherein the processor is configured to confirm the change in operating state based on output from the optical sensor assembly.

22. The portable listening device as recited in claim13, wherein the portable listening device comprises headphones.

23. A carrying case, comprising: a case housing defining first and second earpiece recesses configured to receive first and second earpieces of corresponding headphones; and a permanent magnet positioned adjacent to a portion of the first earpiece recess corresponding to the first earpiece of the corresponding headphones, the permanent magnet being positioned to emit a magnetic field that interacts with a sensor within the first earpiece of the headphones.

24. The carrying case as recited in claim 23, wherein the magnetic field emitted by the permanent magnet includes one or more characteristics detectable by the sensor within the first earpiece.

25. The carrying case as recited in claim 23, wherein the first and second earpiece recesses are configured to receive respective first and second earcups of the corresponding headphones.

26. A system, comprising: a carrying case, comprising: a case housing defining first and second earcup recesses configured to receive first and second earcups of corresponding headphones, the carrying case comprising a permanent magnet positioned proximate a periphery of the first earcup recess; and headphones, comprising: first and second earpieces; a headband assembly coupling the first and second earpieces together; a magnetic field sensor positioned along a periphery of the first earpiece; and a processor configured to change an operating state of the headphones in response to detecting a magnetic field emitted by the permanent magnet.

27. The system as recited in claim 26, wherein the headphones further comprise an ambient light sensor, wherein the processor is configured to change the operating state of the headphones to a low power state in response to detecting the magnetic field and receiving low light readings from the ambient light sensor.

28. An earpiece, comprising: an earpiece housing comprising a back wall and side walls that cooperatively define an interior volume; a speaker assembly disposed within the interior volume, the speaker assembly comprising: a permanent magnet defining a channel extending therethrough; a diaphragm; an electrically conductive coil coupled to the diaphragm and configured to generate a first magnetic field that interacts with a second magnetic field emitted by the permanent magnet to induce oscillation of the diaphragm; and a speaker frame member extending across a portion of the back wall of the earpiece housing to further define a rear volume of air that extends through the channel.

29. The earpiece as recited in claim 28, wherein the speaker frame member defines the rear volume such that it extends to a peripheral portion of the earpiece housing that defines an air vent.

30. The earpiece as recited in claim 28, wherein the portion of the back wall is a majority of the back wall.

31. The earpiece as recited in claim 28, wherein an average distance between the speaker frame member and the back wall of the earpiece housing is about 1 mm.

32. The earpiece as recited in claim 28, wherein portions of the speaker frame member are glued to the back wall of the earpiece housing and wherein the rear volume is routed around the portions of the speaker frame member glued to the back wall.

33. The earpiece as recited in claim 28, wherein the permanent magnet is a first permanent magnet and the earpiece further comprises a second permanent magnet surrounding the first permanent magnet and cooperatively forming a channel shaped to accommodate the electrically conductive coil.

34. A portable listening device, comprising: a headband assembly; an earpiece housing defining an interior volume, the earpiece housing being coupled to the headband assembly; a speaker assembly disposed within the interior volume, the speaker assembly comprising: a diaphragm; a permanent magnet defining a channel extending therethrough that connects a rear volume of air disposed directly behind the diaphragm to another volume of air extending radially outward from the diaphragm; and an electrically conductive coil coupled to the diaphragm and configured to generate a first magnetic field that interacts with a second magnetic field emitted by the permanent magnet to induce oscillation of the diaphragm.

35. The portable listening device as recited in claim 34, wherein the other volume of air extends across a majority of a rear wall of the earpiece housing.

36. The portable listening device as recited in claim 34, further comprising a speaker frame member that defines the other volume of air extending radially outward from the diaphragm.

37. An earpiece, comprising: a housing defining a cavity configured to accommodate an ear of a user; a speaker disposed within the housing; a first battery disposed within the housing; and a second battery disposed within the housing, the cavity being positioned between the first and second batteries.

38. The earpiece as recited in claim 37, wherein the first and second batteries are tilted diagonally away from the cavity.

39. The earpiece as recited in claim 37, further comprising third and fourth batteries disposed within the housing.

40. The earpiece as recited in claim 39, wherein the first, second, third and fourth batteries are each discrete battery assemblies.

41. The system as recited in claim 26, wherein the carrying case further comprises a second permanent magnet positioned proximate a periphery of the second earcup recess.