Patent Publication Number: US-11659317-B2

Title: In-ear speaker hybrid audio transparency system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/844,604, filed Apr. 9, 2020 and issued as U.S. Pat. No. 11,336,986 on May 17, 2022, which is a continuation of U.S. application Ser. No. 16/521,497, filed Jul. 24, 2019 and issued as U.S. Pat. No. 10,652,646 on May 12, 2020, which is a continuation of U.S. patent application Ser. No. 16/399,798, filed Apr. 30, 2019, which is a continuation of U.S. application Ser. No. 15/713,302, filed Sep. 22, 2017, which is a continuation of U.S. application Ser. No. 15/000,994, filed Jan. 19, 2016 and issued as U.S. Pat. No. 9,774,941 on Sep. 26, 2017, which are incorporated herein by reference in their entirety. 
    
    
     FIELD 
     Embodiments described herein relate to an in-ear speaker (e.g., an earbud). More particularly, the embodiments described herein relate to an insertable in-ear speaker that is configured as a hybrid, audio transparency system. Other embodiments are also described. 
     BACKGROUND INFORMATION 
     Wired or wireless in-ear speakers (e.g., earbuds) deliver sounds to one or more ears of a user (also referred to here as a listener or wearer) of such an in-ear speaker. One type of in-ear speaker is designed to be closely coupled to a user&#39;s ear canal, referred to as an “insertable in-ear speaker”. This type in-ear speaker can be placed inside a concha at the entrance of the user&#39;s ear canal or can be inserted into the ear canal to block its entrance. 
     Generally there are two mutually exclusive types of insertable in-ear speakers, which are as follows: (i) an insertable in-ear speaker that fully seals an ear canal (hereinafter “sealable insertable in-ear speakers”); and (ii) an insertable in-ear speaker that is intentionally designed to allow some sounds from the ambient environment to leak into the user&#39;s ear canal during use (hereinafter “leaky insertable in-ear speakers”). Leaky insertable in-ear speakers provide better audio transparency than sealable insertable in-ear speakers. Nevertheless, sounds from the ambient environment may be unwanted to a user. To avoid this scenario, sealable insertable in-ear speakers may be used by the user. Sealable insertable in-ear speakers have some shortcomings. Users of these types of in-ear speakers can be subjected to unwanted sounds resulting from an occlusion effect (OE) during use (e.g., during telephone calls, while running, etc.). Also, a sealable insertable in-ear speaker can prevent its user from perceiving sounds from the ambient environment. 
     SUMMARY 
     Embodiments of an insertable in-ear speaker that is configured as a hybrid transparency system are described. Such an in-ear speaker can assist with at least one of: (i) improving a user&#39;s isolation from sounds from the ambient environment by preventing those sounds from entering the ear canal; or (ii) improving a user&#39;s perception of audio transparency by enabling delivery of sounds from the ambient environment to the ear canal. 
     An insertable in-ear speaker is configured as a hybrid transparency system that combines the use of an active, venting or acoustic pass valve, with an ambient sound pickup and production (also referred to here as ambient sound augmentation) system. A user content sound system, e.g., having an electro-acoustic transducer (speaker driver) that is integrated within a housing of the in-ear speaker, generates user content sound, in accordance with a first audio signal, e.g., containing user content such as an on-going telephone conversation between the wearer of the in-ear speaker and a far end user, music playback, or playback of another audio-containing work. The user content sound is produced for delivery into an ear canal of a wearer of the in-ear speaker. The in-ear speaker may be a sealing type, which seals the ear canal. The in-ear speaker housing also contains the venting or acoustic pass valve which can be configured (alternately) into a state in which it enables sound waves inside the ear canal to travel to an ambient environment, and into another state in which it restricts the sound waves from traveling to the ambient environment. An external microphone is configured to produce a second audio signal (ambient content signal) from sound waves in the ambient environment. The external microphone may also be integrated into the in-ear speaker housing, in such a way that it becomes positioned in a concha, close to the ear canal, when the in-ear speaker is worn; it is referred to as “external” since its primary acoustic input port may be facing outward into the ambient environment. There is also logic circuitry, e.g., as part of a programmed processor, which may or may not be installed within the in-ear speaker housing, that is configured to implement an equalizer (e.g., a spectral shaping digital filter) that adjusts a frequency component of the second audio signal (representing the ambient sound as picked up by the external microphone). The adjustment can be based on an equalization profile of the ear canal. After the adjustment, the second audio signal can be delivered to the ear canal by being converted into sound waves, e.g., by being combined with the second audio signal and then converted into sound using the user content sound system, or the same electro-acoustic transducer that is being used to convert the user content into sound. 
     The equalization profile may be a collection of one or more acoustic characteristics or properties, associated with the ear canal. These may include, but are not limited to, a sound pressure associated with the ear canal; a particle velocity associated with the ear canal; a particle displacement associated with the ear canal; an acoustic intensity associated with the ear canal; an acoustic power associated with the ear canal; a sound energy associated with the ear canal; a sound energy density associated with the ear canal; a sound exposure associated with the ear canal; an acoustic impedance associated with the ear canal; an audio frequency associated with the ear canal; or a transmission loss associated with the ear canal. For one embodiment, the one or more acoustic properties are determined by an ear canal identification module, based on an acoustic test signal picked up by a microphone of the in-ear speaker, while the in-ear speaker is being worn by its end user. In another embodiment, the one or more acoustic properties are computed based on an average of multiple acoustic properties associated with multiple ear canals, e.g., as determined in a laboratory setting. 
     For one embodiment, the logic is further configured to activate or trigger operation of an ambient sound augmentation system that uses the external microphone, only when the valve is enabling sound waves of the first audio signal inside the ear canal to travel to the ambient environment, e.g., the valve is in its open state. In one embodiment, the in-ear speaker that is configured as a hybrid transparency system also operates as part of an active noise control (ANC) system that performs acoustic noise cancellation upon any unwanted sound in the ear canal. The ANC system may also be used to compute one or more acoustic properties of the ear canal that are part of the equalization profile (which is used to configure the spectral shaping function of the equalizer.) 
     For one embodiment, a computer implemented method of using an insertable in-ear speaker as a hybrid transparency system is as follows. One or more user content audio signals are converted into sound that is delivered into an ear canal of the wearer by the in-ear speaker, while the in-ear speaker is sealing off the ear canal against ambient sound leakage. During this playback, the sound inside the ear canal (including the playback of the user content audio signal) is either allowed to travel to an ambient environment or is restricted, by an active, venting/acoustic pass valve. When the valve is open, an ambient content audio signal that contains pickup of sound in the ambient environment surrounding the in-ear speaker is generated and converted into sound, that is also delivered into the ear canal, so that both user content and ambient content can be heard by the wearer. While doing so, a frequency component of the ambient content audio signal is adjusted based on an equalization profile of the ear canal. This hybrid approach of opening a venting/acoustic pass valve combined with ambient sound augmentation aims to improve transparency of the in-ear speaker, so that the wearer can more comfortably perceive the ambient sound content over a broader frequency range (despite wearing the in-ear speaker.) The ambient sound augmentation may be deactivated, and acoustic noise cancellation (ANC) is activated, when the valve is closed (while there may or may not be simultaneous playback of the user content). The ANC in that case aims to produce an anti-noise or anti-phase sound field within the ear canal that is designed to destructively interfere with unwanted sounds that may be generated within the ear canal such as due to walking or physical activity of the wearer. 
     The above summary does not include an exhaustive list of all aspects of the present invention. It is contemplated that the invention includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the Detailed Description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above summary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment of the invention in this disclosure are not necessarily to the same embodiment, and they mean at least one. Also, in the interest of conciseness and reducing the total number of figures, a given figure may be used to illustrate the features of more than one embodiment of the invention, and not all elements in the figure may be required for a given embodiment. 
         FIGS.  1 A- 1 B  are illustrations of occlusion and isolation effects in an ear canal. 
         FIG.  2    is an illustration of an in-ear speaker that contains a venting or acoustic pass valve. 
         FIGS.  3 A- 3 C  are charts illustrating sound levels in an ear canal based on  FIGS.  1 A,  1 B, and  2   , respectively. 
         FIG.  4    is a cross-sectional side view illustration of an exemplary acoustic driver that is presently utilized. 
         FIG.  5 A  is a cross-sectional side view illustration of one embodiment of a balance armature based (BA based) valve. 
         FIG.  5 B  is a cross-sectional side view illustration of another embodiment of a BA based valve. 
         FIG.  6 A  is a cross-sectional top view illustration of one embodiment of a membrane or diaphragm (hereinafter “membrane”) that is included in at least one of the BA based valves illustrated in  FIGS.  5 A- 5 B . 
         FIG.  6 B  is a cross-sectional side view illustration of the membrane illustrated in  FIG.  6 A . 
         FIG.  7 A  is a block diagram side view illustration of one embodiment of a bi-stable operation of at least one of the BA based valves illustrated in  FIGS.  5 A- 5 B . 
         FIG.  7 B  is a block diagram side view illustration of one embodiment of another bi-stable operation of at least one of the BA based valves illustrated in  FIGS.  5 A- 5 B . 
         FIG.  8    is a cross-sectional side view illustration of one embodiment of a driver assembly that includes the BA based valve illustrated in  FIG.  5 A . 
         FIG.  9    is a cross-sectional side view illustration of one embodiment of a driver assembly that includes the BA based valve illustrated in  FIG.  5 B . 
         FIG.  10 A  is a cross-sectional side view illustration of yet another embodiment of a BA based valve. 
         FIG.  10 B  is a cross-sectional side view illustration of one additional embodiment of a BA based valve. 
         FIG.  11 A  is a cross-sectional top view illustration of one embodiment of a membrane that is included in at least one of the BA based valves illustrated in  FIGS.  10 A- 10 B . 
         FIG.  11 B  is a cross-sectional side view illustration of the membrane illustrated in  FIG.  11 A . 
         FIG.  12 A  is a block diagram side view illustration of one embodiment of a bi-stable operation of at least one of the BA based valves illustrated in  FIGS.  10 A- 10 B . 
         FIG.  12 B  is a block diagram side view illustration of one embodiment of another bi-stable operation of at least one of the BA based valves illustrated in  FIGS.  10 A- 10 B . 
         FIG.  13    is a cross-sectional side view illustration of one embodiment of a driver assembly that includes the BA based valve illustrated in  FIG.  10 A . 
         FIG.  14    is a cross-sectional side view illustration of one embodiment of a driver assembly that includes the BA based valve illustrated in  FIG.  10 B . 
         FIG.  15    is a cross-sectional side view illustration of yet another embodiment of a driver assembly that includes the BA based valve illustrated in  FIG.  5 A . 
         FIG.  16    is a cross-sectional side view illustration of another embodiment of a driver assembly that includes the BA based valve illustrated in  FIG.  10 A . 
         FIG.  17    is an illustration of an in-ear speaker in use, and a model of associated acoustic impedances. 
         FIG.  18    is an illustration of an in-ear speaker that is configured as a hybrid transparency system in accordance with one embodiment. 
         FIG.  19    is a chart illustrating how the in-ear speaker illustrated in  FIG.  18    can be used to adjust a characteristic of an audio signal that reflects the sound content from an ambient environment of the in-ear speaker of  FIG.  18   . 
         FIG.  20    is a block diagram of the in-ear speaker configured as a hybrid transparency system 
         FIG.  21    is a process of using an insertable in-ear speaker as a hybrid transparency system in accordance with one embodiment. 
         FIGS.  22 A-B  are charts illustrating at least one benefit of an in-ear speaker that includes at least one of a BA based valve or a sound augmentation system in accordance with one embodiment. 
         FIG.  23    illustrates an exemplary data processing system according to one or more of the embodiments described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of an insertable in-ear speaker that is configured as a hybrid transparency system are described. Such an in-ear speaker can assist with at least one of: (i) improving a user&#39;s isolation from sounds from the ambient environment by preventing those sounds from entering the ear canal; or (ii) improving a user&#39;s perception of audio transparency by enabling delivery of sounds from the ambient environment to the ear canal. 
     Description of at least one of the embodiments set forth herein is made with reference to figures. However, certain embodiments may be practiced without one or more of these specific details, or in combination with other known methods and configurations. In the following description, numerous specific details are set forth, such as specific configurations, dimensions and processes, etc., in order to provide a thorough understanding of the embodiments. In other instances, well-known processes and manufacturing techniques have not been described in particular detail in order to not unnecessarily obscure the embodiments. Reference throughout this specification to “one embodiment,” “an embodiment,” “another embodiment,” “other embodiments,” “some embodiments,” and their variations means that a particular feature, structure, configuration, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “for one embodiment,” “for an embodiment,” “for another embodiment,” “in other embodiments,” “in some embodiments,” or their variations in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, configurations, or characteristics may be combined in any suitable manner in one or more embodiments. 
     The terms “over,” “to,” “between,” and “on” as used herein may refer to a relative position of one layer with respect to other layers. One layer “over” or “on” another layer or bonded “to” or in “contact” with another layer may be directly in contact with the other layer or may have one or more intervening layers. One layer “between” layers may be directly in contact with the layers or may have one or more intervening layers. 
     For one embodiment, a “valve,” and its variations refer to a bi-stable electrical device or system that includes a motor or actuator, e.g., a micro-electromechanical system (MEMS) actuator, or an electro-dynamic actuator having a coil assembly and a magnetic system, such as a balanced armature (BA) system. The valve may be part of an “active vent system” and its variations, which refer to an acoustic system that acoustically couples a sealed ear canal volume to a volume representing an external ambient environment (outside of an ear or outside of an electronic device) using a venting or acoustic pathway. For one embodiment, a “pathway” and its variations refer to a simple network of volumes connected to the valve. For example, and for one embodiment, an active vent system requires a minimal amount of pathways (i.e., volumes) to connect a sealed ear canal volume with a volume representing an external ambient environment (outside of an ear or an electronic device). 
     For one embodiment, a “volume” and its variations refer to a dynamic air pressure confined within a specified three-dimensional space, wherein the volume may be represented as an acoustic impedance. Depending on a geometry of the volume, the volume&#39;s acoustic impedance can behave like a compliance, inertance, (also known as “acoustic mass”), or combination of both. The specified three dimensional space can be expressed in a tangible form as a tubular structure, a cylindrical structure, or any other type of structure with a defined boundary. 
     For one embodiment, an “in-ear speaker” and its variations refer to electronic devices for providing sound to a user&#39;s ear. In-ear speakers are aimed into an ear canal of the user&#39;s ear and may or may not be inserted into the ear canal. An in-ear speaker may include acoustic drivers, microphones and other electronic devices. In-ear speakers may be wired or wireless (for purposes of receiving a user content audio signal from an external device). In-ear speakers include, but are not limited to, earphones, earbuds, hearing aids, hearing instruments, in-ear headphones, in-ear monitors, canalphones, personal sound amplifiers (PSAPs), and headsets. 
     For one embodiment, an “insertable in-ear speaker” and its variations refer to an in-ear speaker that is inserted into an ear canal. This can be achieved via a specified three dimensional space (e.g., a tubular structure, a cylindrical structure, any other type of structure known for facilitating insertion into an ear canal, etc.). 
     For one embodiment, a “sealable insertable in-ear speaker” and its variations refer to an insertable in-ear speaker that fully seals an ear canal. Sealable insertable in-ear speakers prevent sounds from an ambient environment from leaking into an ear canal during use in an ear canal. Sealable insertable in-ear speakers can also result in an occlusion effect during use in an ear canal. 
     For one embodiment, a “leaky insertable in-ear speaker” and its variations refer to insertable in-ear speaker that is intentionally designed to allow some sounds from the ambient environment to leak into the user&#39;s ear canal during use. Leaky insertable in-ear speakers provide better natural audio transparency than sealable insertable in-ear speakers. 
     For one embodiment, “audio transparency” and its variations refer to a phenomenon that occurs when a user can hear all of the sounds around him including sounds from the ambient environment, as well as any user content sound that may or may not be produced and delivered into his ear canal (by a user content sound system of the in-ear speaker.) 
     For one embodiment, an “acoustic driver” and its variations refer to a device including one or more transducers for converting electrical signals into sound. Acoustic drivers include, and are not limited to, a moving coil driver/receiver, a balanced armature (BA) receiver, an electrostatic driver/receiver, an electret driver/receiver, and an orthodynamic driver/receiver. Acoustic drivers can be included in the in-ear speaker, as part of the user content sound system. 
     For one embodiment, a “hybrid transparency system” and its variations refer to a system that assists with enabling a user of such a system to achieve at least one of (i) isolation from sounds from the ambient environment by preventing those sounds from entering the user&#39;s ear canal; or (ii) perception of audio transparency by enabling delivery of sounds from the ambient environment to the ear canal. A hybrid transparency system can include at least one processor that is configured (e.g., programmed) to perform one or more computational functions of the hybrid transparency system. A hybrid transparency system can be implemented as an in-ear speaker, which may be in combination with a personal communication device such as a smartphone, or which may be part of any portable electronic device that converts between electric signals and sound such as a headset or other head worn device. 
     In one aspect, the hybrid transparency system includes at least one of the embodiments of the balanced armature (BA) based valve described herein. In one aspect, at least one of the embodiments of a BA based valve as described herein are incorporated into a driver assembly comprised of one or more acoustic drivers (which form the user content sound system). In one aspect, the driver assembly includes at least one embodiment of a BA based valve as described herein and at least one of (i) one or more BA receivers known in the art; or (ii) one or more acoustic drivers that are not BA receivers (e.g., one or more acoustic drivers that are of the electrodynamic type, etc.) For example, one embodiment of a BA based valve as described herein is included in a driver assembly, such as one of the driver assemblies described in U.S. patent application Ser. No. 13/746,900 (filed Jan. 22, 2013), which was published on Jul. 24, 2014 as U.S. Patent Application Publication No. 20140205131 A1. 
     For one embodiment, the valve and the acoustic driver included in the driver assembly are housed in a single housing of the driver assembly. For one embodiment, a first spout is formed on or coupled to a housing of the driver assembly and is shared by the valve and the acoustic driver. For one embodiment, the first spout is to deliver sound that is output or generated by the acoustic driver housed in the driver assembly, to an ear canal. The driver assembly includes a second spout that is formed on the housing of the driver assembly and is primarily used by the valve described herein. For one embodiment, the second spout is to deliver sound from an ear canal into an ambient environment. For one embodiment, the second spout assists with delivering unwanted sound created by an occlusion effect, into the ambient environment that is outside of the ear canal. For one embodiment, the second spout assists with manipulation of the listener or wearer&#39;s perceived audio transparency. For one embodiment, the second spout assists with regulation of ear pressure caused by pressure differences in the listener&#39;s ear. 
     At least one of the aspects described above enables a single electric signal input (that corresponds to the desired sound) to be fed into one or multiple acoustic drivers in a driver assembly. Furthermore, the single electric signal input can be electrically filtered using different filters (e.g., a high-pass filter, a low-pass filter, a band-pass filter, etc.) and each of the different types of signals can be fed to the one or more corresponding multiple acoustic drivers in the driver assembly (e.g., tweeters, woofers, super woofers, etc.). The filtering can be performed using a crossover circuit that filters the signal input and feeds the different types of signals to the one or more corresponding multiple acoustic drivers in the driver assembly. Moreover, a driver assembly that includes at least one of the embodiments of a valve described herein can assist with reduction or elimination of amplified or echo-like sounds created by an occlusion effect, as well as, manipulation of perceived audio transparency. 
       FIGS.  1 A- 1 B  are illustrations of occlusion and isolation effects  100  in an ear canal  104  of a listener&#39;s ear  102 . The in-ear speaker  106  can be sealable insertable in-ear speaker or a leaky insertable in-ear speaker that includes at least one acoustic driver—e.g., a BA receiver, a moving coil driver/receiver, an electrostatic driver/receiver, an electret driver/receiver, an orthodynamic driver/receiver, etc. 
     With regard to  FIG.  1 A , the occlusion and isolation effects  100  occur when an in-ear speaker  106  seals the ear canal  104 . In order to deliver a desired sound that is produced by the in-ear speaker  106  to a listener&#39;s eardrum  112 , the in-ear speaker  106  can partially or fully seal the ear canal  104 . In other words, the in-ear speaker  106  fills at least some portion of the ear canal  104  to prevent one or more sounds from escaping outside the ear  102 . The sealing of the ear canal  104  can be beneficial for preventing loss of low frequency sounds, whose absence can affect the quality of the desired sound being delivered to the ear. Nevertheless, consequences of a sealed ear condition include occlusion and isolation effects  100 , which can interfere with a listener&#39;s ability to enjoy or perceive the desired audio. 
     With regard to an occlusion effect  100 , the sealing of the ear canal  104  causes the listener to perceive amplified or echo-like sounds  110  of the listener&#39;s own voice (e.g., when the listener is talking, etc.) or amplified or echo-like sounds  110  created in the listener&#39;s mouth (e.g., sounds created by chewing food, sounds created due to a movement of a listener&#39;s body, etc.). Specifically, the occlusion effect  100  is primarily caused by bone and tissue-conducted sound vibrations  108  reverberating off the in-ear speaker  106  filling the ear canal  104 . The amplified sounds  110  are caused by the volume of air between the tympanic membrane and the in-ear speaker  106  filling the ear canal  104  becoming excited from bone and tissue conduction. 
     In addition, the sealing of the ear canal  104  creates an isolation effect  100  that prevents one or more sounds from the ambient environment from entering into the listener&#39;s ear canal  104  and reaching the ear drum  112 . This isolation effect  100  can be unwanted, especially in situations where the listeners wants to receive sounds generated by the in-ear speaker  106  and also receive one or more sounds from the ambient environment outside the ear  102 . 
     Generally, and as shown in  FIG.  1 B , the occlusion and isolation effects  100  are not noticeable to most listeners. Specifically, the occlusion effect  100  is not noticeable when listeners are talking or engaged in an activity because the vibrations  108  that cause amplified sounds  110 , normally escape through the open ear canal  104  into the ambient environment. Nevertheless, and as shown in  FIG.  1 A , when the ear canal  104  is sealed by the in-ear speaker  106 , the vibrations  108  cannot exit the ear canal  104 , and as a result, the sounds  110  become amplified or echo-like because they are reflected back toward the eardrum  112  in the ear  102 . Compared to the completely open ear canal  104  in  FIG.  1 B , the occlusion effect  100  can boost low frequency sound pressure (usually below 500 Hz) in the ear canal  100  by 20 dB or more, as described below in connection with  FIGS.  3 A- 3 C . The open ear canal  104  also enables one or more sounds from an ambient environment to perceived by listeners, which in turn reduces or eliminates the isolation effect  100 . 
     Some users of in-ear speakers, such as the in-ear speaker  106 , may find the amplified or echo-like sounds created by the occlusion effect  100  or the inability to perceive sound(s) from the ambient environment that results from the isolation effect to be annoying and distracting when they are listening to sound delivered by such in-ear speakers. 
     Thus, several ways to mitigate or eliminate the occurrence of occlusion and isolation effects are presently utilized. One way to reduce or eliminate the occurrence of an occlusion effect includes combining the in-ear speaker  106  in  FIGS.  1 A- 1 B  with an active noise control or acoustic noise cancellation (“ANC”) digital processor and its associated, error microphone, both of which are not shown in  FIGS.  1 A- 1 B . The error microphone can be used to pick up the amplified sounds  110  created by the occlusion effect  100 , which are then converted to digital audio signals and processed by the ANC processor into an anti-phase estimate of the unwanted sounds  110 ; the anti-phase estimate is then converted into a sound field by an acoustic driver of the in-ear speaker  106 , in hopes of destructively interfering with and therefore reducing the unwanted sounds  110  created by the occlusion effect  100 . Nevertheless, this way of reducing the occlusion effect  100  requires the use of digital signal processing (“DSP”), which can result in a level of power consumption that is not ideal for some types of in-ear speakers (e.g., a size-critical in-ear speaker, a wireless in-ear speaker, etc.). 
     With regard to isolation effects, one way of reducing these effects includes use of a leaky insertable in-ear speaker (as opposed to sealable insertable in-ear speakers). Leaky insertable in-ear speakers provide better audio transparency than sealable insertable in-ear speakers. Nevertheless, sounds from the ambient environment may be unwanted to a user. To avoid this scenario, sealable insertable in-ear speakers may be used by the user. Thus, the user may have to gain access to both sealable insertable in-ear speakers and leaky insertable in-ear speakers in order to avoid the shortcomings of both. 
       FIG.  2    is an illustration of an in-ear speaker  206  including one embodiment of a venting or acoustic pass valve  210  that can assist with mitigating or eliminating an occlusion effect  200  in an ear canal  104 .  FIG.  2    is a modification of  FIGS.  1 A- 1 B , which are described above. In contrast with the in-ear speaker  106  of  FIG.  1 A , the in-ear speaker  206  includes a venting or acoustic pass valve  210  that acts as a switching valve that can be signaled (switched) open, in order to allow some of the amplified or echo-like sounds  110  to escape (vent or pass) into the ambient environment, instead of being reflected onto eardrum  112 . The escaped sounds  212  consequently reduce (or even eliminate) the amplified or echo-like sounds  110  that are perceived by the listener. In this way, the occlusion effect  200  can be reduced or eliminated. The in-ear speaker  206  can include the valve  210  and at least one acoustic driver—e.g., a BA receiver, a moving coil driver/receiver, an electrostatic driver/receiver, an electret driver/receiver, an orthodynamic driver/receiver, etc. 
     In addition, the valve  210  can be used to improve an isolation effect. The valve  210  can be signaled (switched) closed, to prevent sounds from the ambient environment from entering into the ear canal  104 . 
     For one embodiment, the valve  210  is a bi-stable electrical device or system that consumes a minimal amount of power, when compared with the DSP-based system described above having an ANC processor and an error microphone. Specifically, and for one embodiment, a motor of the BA based valve  210  is designed to be bi-stable, so that the power consumption of the valve  210  occurs only when the valve  210  is moving between its two states, as an open valve or a closed valve. For this embodiment, power is not needed when the valve  210  is not changing from a closed position to an open position and vice versa. In this way, the valve  210  can be used to reduce or eliminate the occlusion effect in an in-ear speaker  206 , without the increased levels of power consumption associated with an ANC processor and an error microphone. Additional details about the bi-stable operation of one embodiment of a valve  210  that is BA-based are described below in connection with  FIGS.  5 A- 7 B . The valve  210  illustrated in  FIG.  2    can be similar to or the same as at least one of the BA based valves described below in connection with at least one of  FIGS.  5 A- 17   . 
       FIGS.  3 A,  3 B, and  3 C  are charts illustrating sound levels in a listener&#39;s ear canal based on the occlusion effects described above in  FIGS.  1 A,  1 B, and  2   , respectively. With regard to  FIGS.  3 A and  3 B , a comparison of curve  302  with curve  304  shows that low frequency sounds between 100 Hz and 1000 Hz that would normally escape from a completely open ear canal  104  become amplified when the occlusion effect  100  is caused by a sealing of the ear canal  104  by the in-ear speaker  106 . Specifically, curve  302  shows that low frequency sounds between 100 Hz and 1000 Hz are amplified by as little as 10 dB SPL (sound pressure level) to as much as 25 dB SPL. 
     With regard to  FIG.  3 C , curve  306  represents the level of sound amplification attributable to the occlusion effect  200  that is caused when one embodiment of the in-ear speaker  206  seals the ear canal  104 . A comparison of curve  306  with curve  304  shows that the low frequency sounds between 100 Hz and 1000 Hz are amplified less severely when the in-ear speaker  206  seals the ear canal  104  than when the in-ear speaker  106  seals the ear canal  104 . For one embodiment, the cause of the less severe amplification is due to the BA based valve  210  acting as a switching valve within the in-ear speaker  206 . 
       FIG.  4    is a cross-sectional side view illustration of an exemplary acoustic driver  400  that is presently utilized. The in-ear speaker may contain the acoustic driver  400 , thereby enabling its wearer to hear user content such as a telephone call conversation or a musical work (reflected in an audio signal at the input of the acoustic driver  400 ). The specific type of acoustic driver  400  that is illustrated in  FIG.  4    is a balanced armature (BA) receiver. The acoustic driver  400 , however, is not so limited. This acoustic driver  400  can be any type of acoustic driver—e.g., a BA receiver, a moving coil driver/receiver, an electrostatic driver/receiver, an electret driver/receiver, an orthodynamic driver/receiver, etc. 
     The acoustic driver  400  includes a housing  402  that holds, encases, or is attached to one or more of the components of the acoustic driver  400 . Furthermore, and for one embodiment, the housing  402  includes a top side, a bottom side, a front side, and a rear side. For one embodiment, the front side of the housing  402  is substantially parallel to the rear side of the housing  402 , while the top side of the housing  402  is substantially parallel to the bottom side of the housing  402 . When the acoustic driver  400  is part of an in-ear speaker that is placed in a user&#39;s ear, the rear side of the housing  402  is further away from the user&#39;s ear canal than the front side of the housing  402  and the rear side of the housing  402  is closer to an ambient environment than the front side of the housing  402 . 
     In the illustrated example of the acoustic driver  400 , a spout  404 A is formed on or attached to the front side of housing  402 ; a terminal  418  is formed on or attached to the rear side of housing  402 ; the spout  404 A is closer to the top side of housing  502 ; and the spout  404 A is farther from the bottom side of housing  402 . The spout  404  is formed on or welded to housing  402  to enable one or more sound waves converted from one or more electrical signals by acoustic driver  400  to be delivered or emitted into an ear of a listener (e.g., ear  102  of  FIGS.  1 A- 2   ) or an ambient environment. The acoustic driver  400  outputs the sound waves using a membrane or diaphragm (hereinafter “membrane”)  406 , a drive pin  412 , a coil assembly  414 , an armature or a reed (hereinafter “armature”)  416 , a terminal  418 , and a magnetic system. The magnetic system of the acoustic driver  400  includes an upper magnet  422 A, a lower magnet  422 B, a pole piece  424 , and an air gap  430 . The acoustic driver  400  also includes an electrical cable or connector  428  between the terminal  418  and the coil assembly  414 . The terminal  418  is electrically connected to a flex circuit (not shown) that provides an input electrical signal to the acoustic driver  400 . The flex circuit (not shown) is used to provide one or more electrical input signals from a crossover circuit (not shown) to the acoustic driver  400 . The crossover circuit is electrically connected to one or more external devices that generate the one or more electrical input signals. It is to be appreciated that the crossover circuit is not always necessary, especially when the electrical input signal is not being filtered. 
     Operation of the acoustic driver  400  begins when the one or more electrical input audio signals are received at the terminal  418  and passed on to the coil assembly  414 , via the connector  428 . In response to receiving the electrical input audio signal, the coil assembly  414  produces electromagnetic forces that trigger a movement of the armature  416  in the directions  426 A and  426 B in the air gap  430 . Generally, the magnetic system of the acoustic driver  400  (which includes the upper magnet  422 A, the lower magnet  422 B, the pole piece  424 , and the air gap  430 ) is tuned to prevent the armature  416  from being in contact with either of the magnets  422 A-B. In this way, the armature  416  oscillates between the magnets  422 A-B while produces the sound waves. The drive pin  412 , which is connected to the armature  416  and the membrane  406 , moves in proportion to the oscillating movements of the armature  416 . The movements of the drive pin  412  cause vibrations or movements of the membrane  406 , which create sound waves in the air above the membrane  406 , as per the variation in the coil current of the coil assembly  414  dictated by the audio signal. 
     The coil assembly  414  can, for example, be a coil winding that is wrapped around a bobbin or any other type of coil assembly known in the art. The armature can be placed through the coil assembly  414 . The armature  416  can be optimized based on its shape or configuration to enable production of a broad band of sound frequencies (e.g., low, mid-range, high frequencies, etc.). Furthermore, the drive pin  412  can be connected to the membrane  406  using an adhesive or any other coupling mechanism known in the art. 
       FIG.  5 A  is a cross-sectional side view illustration of one embodiment of a BA based valve  500 . The BA based valve  500  is a modification of the acoustic driver  400  of  FIG.  4   . For the sake of brevity, only the differences between the acoustic driver  400  (which is described above in connection with  FIG.  4   ) and the BA based valve  500  will be described below in connection with  FIG.  5   . 
     Some differences between the example of the acoustic driver  400  depicted in  FIG.  4    and the BA based valve  500  relate to the presence of two spouts  504 A-B, a membrane  506  (including a valve flap  508  and a hinge  510 ), an armature  516 , a coil assembly  514 , two magnets  522 A-B, a pole piece  524 , and an air gap  530  in the BA based valve  500 . For a first example, and for one embodiment, the valve flap  508  of the membrane  506  of the BA based valve  500  can be in an open position  508 A or a closed position  508 B, while the membrane  406  of the acoustic driver  400  lacks any valve flap or other mechanism capable of being opened or closed. For a second example, and for one embodiment, the membrane  506  of the BA based valve  500  does not vibrate to create sound, while the membrane  406  of the acoustic driver  400  vibrates to create sound. 
     For one embodiment, the BA based valve  500  includes two spouts  504 A and  504 B, which may be formed on or coupled to the housing  502  as is known in the art. For the illustrated embodiment of the BA based valve  500 , the spout  504 A is formed on or coupled to the front side of the housing  502 ; the spout  504 B and a terminal  518  are formed on or attached to the rear side of the housing  502 ; the spout  504 A is closer to the top side of the housing  502 ; the spout  504 A is farther from the bottom side of the housing  502 ; and the spout  504 B is closer to the bottom side of the housing  502 . 
     For one embodiment, the spout  504 A is similar to or the same as the spout  404 , which is described above in  FIG.  4   . For one embodiment, the spout  504 A works in combination with the spout  504 B to diffuse amplified or echo-like sounds that are created by an occlusion effect, outward into an ambient environment or away from a listener&#39;s ear canal, so as to mitigate or eliminate the unwanted sounds. For one embodiment, the spout  504 B is similar to the spout  404  (which is described above in  FIG.  4   ); however, the spout  504 B does not face the ear canal of the listener. For this embodiment, spout  504 B faces outward or opens to the ambient environment to enable amplified sound waves created by an occlusion effect to be delivered or emitted into the ambient environment away from the ear canal of the listener. 
     For one embodiment, the amplified or echo-like sound created by an occlusion effect is diverted into the ambient environment when the valve flap  508  is open. For one embodiment, the sound from the ambient environment is restricted from entering the ear canal when the valve flap  508  is closed. The valve flap  508  of the membrane  506  is open at the position  508 A and closed at the position  508 B. For one embodiment, the hinge  510  is created as part of the membrane  506  to enable the opening and closing of the valve flap  508 . For one embodiment, when the valve flap  508  is in the open position  508 A, the spouts  504 A-B work together to divert some or all of the amplified or echo-like sounds created by an occlusion effect out away from a listener&#39;s ear canal. In this way, the BA based valve  500  can enable a listener to reduce an occlusion effect, when desired. 
     For one embodiment, an in-ear speaker that includes the BA based valve  500  can enable manipulation of a listener&#39;s perceived audio transparency, based on the opening or closing of the valve flap  508 . For one embodiment of an in-ear speaker that includes the BA based valve  500 , when the valve flap  508  is in the open position  508 A, a listener can made aware of auditory stimuli in his surroundings because sound waves from the ambient environment can travel through the housing  502  generally along a sound transmission path  520  that connects the two spouts  504 A-B. For this embodiment, the listener is still receiving ambient sounds, and as a result, his perception of audio transparency is enhanced. For one embodiment of an in-ear speaker that includes the BA based valve  500 , when the valve flap  508  is in the closed position  508 B, the BA based valve  500  acts as an ambient noise blocker, for a listener that does not want to perceive auditory stimuli from his surroundings. For this embodiment, the listener will receive only the sounds that are being actively generated or produced by an acoustic driver of the in-ear speaker, which can be beneficial in certain situations. In this way, the BA based valve  500  can enable a listener to reduce an occlusion effect when desired, become aware of sounds in the ambient environment when desired, or prevent sounds from the ambient environment from reaching the listener&#39;s ear canal when desired. 
     For one embodiment, an in-ear speaker that includes the BA based valve  500  can assist with regulation of ear pressure caused by pressure differences in a listener&#39;s ear. The pressure differences can result from pressure changes in the ambient environment, e.g., as the listener using an in ear-speaker moves—such as in an aircraft&#39;s cabin—from a lower elevation with one level of pressure to a higher elevation that has a different level of pressure, etc. When wearing an in-ear speaker, such ambient pressure changes can be uncomfortable or even painful. For one embodiment, an in-ear speaker that includes the BA based valve  500  can regulate the pressure differences in the listener&#39;s ear when he is using the in-ear speaker. For one embodiment of an in-ear speaker that includes the BA based valve  500 , when the valve flap  508  is in the closed position  508 B, the listener&#39;s ear is isolated from ambient pressure changes. The isolation from ambient pressure changes is achieved because air flow from the ambient environment is prevented from traveling through the housing  502 , between the two spouts  504 A-B. The air pressure above the diaphragm of the in-ear speaker is thus isolated from the air pressure in the ambient environment, and as a result, the listener&#39;s inner ear is sealed off from ambient pressure change. When the valve flap  508  is actuated into the open position  508 A, however, the listener&#39;s ear is no longer isolated from changes in ambient pressure. In this way, the BA based valve  500  can enable a listener to regulate changes in ear pressure that result from ambient pressure changes when desired, reduce an occlusion effect when desired, become aware of sounds in the ambient environment when desired, or prevent sounds from the ambient environment from reaching the listener&#39;s ear canal when desired. 
     For one embodiment, one or more of the control signals that cause the opening or closing of the valve flap  508  can be based on one or more measurements by one or more sensors (not shown) and based on an operating state of an external electronic device (e.g., a smartphone, a computer, a wearable computer system, or other sound source.) The external electronic device may be the source of a user content audio signal that is being delivered using a wired or a wireless link or connection between the external electronic device and the in-ear speaker. For one embodiment, the one or more sensors can include at least one of an accelerometer, a sound sensor, a barometric sensor, an image sensor, a proximity sensor, an ambient light sensor, a vibration sensor, a gyroscopic sensor, a compass, a barometer, a magnetometer, or any other sensor which may be installed within a housing of the in-ear speaker or within a housing of the external electronic device. A purpose of the sensor is to detect a characteristic of one or more environs. For one embodiment, one or more control signals are applied to the coil assembly  514  of the valve that are based on one or more measurements by the one or more sensors. For one embodiment, the one or more sensors are included as part of the BA based valve  500 , as part of an in-ear speaker that includes the BA based valve  500  (e.g., within the external housing of the in-ear speaker—not shown), or they may be part of the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.) In the latter case, the control signal may be provided from outside of the housing  502 , to the BA based valve  500 , via the terminal  518 . 
     For one embodiment, the one or more sensors are coupled to logic that determines, based on one or more measurements by the one or more sensors, when one or more of the control signals that cause the opening or closing of the valve flap  508  are to be applied to the coil assembly  514  (or to another valve actuator). The logic circuitry can be included in the housing  502  of the BA based valve  500 , in the housing of an in-ear speaker in which the BA based valve  500  is contained, or in the housing of an external electronic device (e.g., a smartphone, a tablet computer, a wearable computer system, etc.) that provides the user content electrical audio signals that are converted to sound for a listener (by the in-ear speaker). 
     In a first example, and for one embodiment, the one or more sensors include a sound sensor (e.g., a microphone, etc.). In this first example, the BA based valve  500  is included in an in-ear speaker that is connected to an external electronic device that can play audio/video media files and conduct telephony (e.g., a smartphone, a computer, a wearable computer system, etc.). In this first example, the sound sensor may be included inside the housing  502  of the BA based valve  500 , or it may be in the housing of the in-ear speaker that includes the BA based valve  500 , or in the housing of the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.). In this first example, the logic for determining whether the valve flap  508  is to be opened is included in at least one of the BA based valve  500 , the in-ear speaker that includes the BA based valve  500 , or the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.). In this first example, the listener is listening to audio from the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.) using an acoustic driver that is in the in-ear speaker. When the sound sensor detects the listener&#39;s voice for a threshold amount of time, the logic determines that the listener (with the in-ear speaker in his/her ear) may be engaged in a phone/video call or a conversation with another human. In this first example, the logic provides the one or more control signals that cause the valve flap  508  to be opened, in response to the determination that the listener is on a phone/video call or in a conversation with another human. In this way, the sound sensor, the logic, and the BA based valve  500  assist with a reduction of an occlusion effect that can occur when the listener (with the in-ear speaker in his/her ear) is engaged in a phone/video call or a conversation with another physical human. 
     In a second example, a software component running on the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.) can determine an operating state of a software application (e.g., a media player application, a cellular telephony application, etc.) that is also running in the external device and that may be producing the user content audio signal. Based on this operating state, the software component can determine whether to open or close the valve flap  508  and will then signal the valve actuator (e.g., the coil assembly  514 ) accordingly. For one embodiment, the software component on the external electronic device can also use data from the one or more sensors (e.g., the sound sensor, an accelerometer, etc.) in addition to the operating state of the software application, to determine whether to open or close the valve flap  508 . In this second example, and for one embodiment, the sound sensor initially detects no sound from the listener (e.g., the listener is not talking but is listening to audio from the in-ear speaker) and the software component determines one or more operating states of an application on the external electronic device. In this second example, and for one embodiment, one determined operating state is that a media player application is being used to generate the user content audio signal (that is being converted into sound by the acoustic driver in the in-ear speaker) as the listener is listening to audio; and another determined operating state is that a cellular telephony application is not being used, because no phone/video call has been placed or received. In this case, the software component can, based on the operating state of the applications and the data from the sound sensor, cause one or more control signals to be sent to a valve actuator (e.g., the coil assembly  514 ) to close the valve flap  508 . Shortly after this, the operating state of an application on the external electronic device may change because a phone call begins (e.g., a call is placed or received using the cellular telephony application, etc.), and the sound sensor detects that the listener is speaking. In this further case, based on the change in the operating state of the application and the based on data from the sound sensor, the software component causes a control signal to be sent to the valve actuator to open the valve flap  508 . 
     In a third example, and for one embodiment, the one or more sensors include a sound sensor and an accelerometer. In this third example, as in the second example given above, an acoustic driver of the in-ear speaker is connected to receive a user content audio signal from an external electronic device that can play audio/video media and act as a telecommunications device (e.g., a smartphone, a computer, a wearable computer system, etc.). The sound sensor is included in at least one of the valve  210  (e.g., the BA based valve  500 ), the in-ear speaker that includes the BA based valve  500 , or the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.). In this third example, the accelerometer is included in at least one of the BA based valve  500 , the in-ear speaker that includes the BA based valve  500 , or the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.). In this third example, the logic for determining whether the valve flap  508  is to be opened can be included in at least one of the BA based valve  500 , the in-ear speaker that includes the BA based valve  500 , or the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.). In this third example, the listener is watching a video and/or listening to audio from the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.) using the in-ear speaker that includes the BA based valve  500 . In this third example, the sound sensor does not detect the listener&#39;s voice for a threshold period of time, and the logic determines that the listener is not engaged in a phone/video call on the external electronic device and is not engaged in a conversation with another physical person. In addition, and in this third example, the accelerometer detects that the listener has been moving for a threshold period of time, and as a result, the logic determines that the listener is engaged in a physical activity (e.g., walking, running, lifting, etc.). In this second example, the logic in response to detecting physical activity by the listener provides one or more control signals to the terminal  518  that cause the valve flap  508  to open, in response to the determination that the listener is engaged in a physical activity even though the listener is not engaged in a conversation with a physical human and not engaged in a phone/video call. In this way, the sound sensor, the accelerometer, the logic, and the BA based valve  500  assist with manipulation of audio transparency even when the listener (with the in-ear speaker in his/her ear) is not engaged in a phone/video call or a conversation with a physical human. 
     In a fourth example, and for one embodiment, the one or more sensors include a barometric sensor. In this fourth example, the BA based valve  500  is included in an in-ear speaker that is connected to an external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.). In this fourth example, the barometric sensor is included in at least one of the BA based valve  500 , the in-ear speaker that includes the BA based valve  500 , or the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.). In this fourth example, logic for determining whether the valve flap  508  is to be opened or closed can be included in at least one of the BA based valve  500 , the in-ear speaker that includes the BA based valve  500 , or the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.). In this fourth example, and for one embodiment, the listener is using the in-ear speaker that includes the BA based valve  500  with the external electronic device to perform an activity (e.g., watching a video, listening to audio, browsing the internet, etc.). In this fourth example, the barometric sensor detects a change in the ambient air pressure by a threshold amount and/or for a threshold period of time. In this fourth example, in response to measurements of the barometric sensor, the logic determines that the pressure changes in the listener&#39;s ear could be uncomfortable or painful for the listener. In this fourth example, the logic provides one or more of the signals that cause the closing of the valve flap  508  in order to assist with isolating the listener&#39;s ear pressure from the ambient pressure changes. For one embodiment, the logic provides the one or more signals to the terminal  518  in response to the determination that that the pressure changes in the listener&#39;s ear may be uncomfortable or painful for the listener. In this way, the barometric sensor, the logic, and the BA based valve  500  assist with regulation of pressure changes in a listener&#39;s ear. 
     For one embodiment, a programmed processor, or a software component being executed by a processor on the external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.), can analyze and/or gather data provided to or received by one or more software applications (e.g., an atmospheric pressure monitoring application, a weather monitoring application, etc.) that are running on the external electronic device. For one embodiment, based on the analyzed and/or gathered data, the software component determines whether to open or close the valve flap  508  and then sends an appropriate control signal to the coil assembly  514  (that controls the drive pin  512 ). In a fifth example, and for one embodiment, data is analyzed and/or gathered from a weather monitoring application that is receiving measurements of the atmospheric pressure in the listener&#39;s ambient environment from a network. In this fifth example, the software component determines that there has been a change in the atmospheric pressure for a threshold period of time and/or by a threshold amount based on the analyzed and/or gathered data. In this case, the software component can, based on the analyzed and/or gathered data, cause one or more control signals to be sent to the coil assembly  514  to close the valve flap  508 . Now, shortly after this, assume that the analyzed and/or gathered data changes (e.g., the software component determines, using data from the weather monitoring application, that the atmospheric pressure has remained stable for a threshold amount of time). In this further case, based on the change in the analyzed and/or gathered data, the software component causes one or more control signals to be sent to the coil assembly to open the valve flap  508 . In this way, the logic, the software component of the external electronic device, and the BA based valve  500  assist with regulation of pressure changes in a listener&#39;s ear. 
     Other examples and/or embodiments are also possible. It is to be appreciated that the immediately preceding examples are merely for illustration and are not intended to be limiting. This is because there are numerous types of sensors that cannot be listed or described herein; and because there are numerous ways in which the numerous types of sensors can be used and/or combined to trigger an opening or closing of the valve  210  (e.g., using the valve flap  508  in the case of the BA based valve  500 .) It is also to be appreciated that one or more of the examples and/or embodiments described above can be combined or practiced without all of the details set forth in the examples and/or embodiments described above. 
     For one embodiment, the logic that determines, based on one or more measurements of the one or more sensors, when one or more of the signals that cause the opening or closing of the valve flap  508  are applied to the coil assembly  514  can be manually overridden by the listener, to open or close the valve flap  508  when the listener chooses. For example, and for one embodiment, an external electronic device (which is electrically connected to an in-ear speaker that includes the BA based valve  500 ) can include one or more input devices that enable a listener to provided one or more direct inputs that cause the logic to directly provide one or more control signals that cause the coil assembly  514  to open or close the valve flap  508  (as indicated by the direct inputs from the listener). For this embodiment, the logic is forced to provide the control signal to the valve actuator based one or more direct inputs that are provided to the external electronic device (containing the logic.) For one embodiment, the external electronic device includes, but is not limited to, the in-ear speaker that includes the BA based valve  500 , a smartphone, a computer, and a wearable computer system. 
     For one embodiment of the BA based valve  500 , as depicted in  FIG.  5 A  for example, each of the membrane  506 , the valve flap  508 , the hinge  510 , the armature  516 , and the magnetic assembly (which includes the coil assembly  514 , the two magnets  522 A-B, the pole piece  524 , and the air gap  530 ) is specially designed so that the armature  516  (and by extension, the drive pin  512 ) is operable in a bi-stable manner. For one embodiment, the bi-stable operation of the armature  516  results from an application of one or more electrical input or control signals, from a low power current source to the coil assembly  514 , which in turn creates a magnetic flux that causes the armature to move upward  526 A towards the upper magnet  522 A or downwards  526 B towards the magnet  522 B. The magnets  522 A-B are of sufficient magnetic strength to cause the armature  516  to make contact with the magnets  522 A-B, and this causes the drive pin  512  to either actuate valve  508  into the open position  508 A or the closed position  508 B. To achieve this bi-stable operation, each of the membrane  506 , the valve flap  508 , the hinge  510 , the armature  516 , and the magnetic assembly of the BA based valve  500  are made from materials that result in an opening or a closing of the valve flap based on the low power current provided to the coil assembly  514 , via the terminal  518 . Additional details about the opening or the closing of the valve flap  508  based on a low power current are described below in connection with  FIGS.  7 A- 7 B . 
     For one embodiment, the membrane  506  has a substantially rectangular shape, is between the top and bottom sides of housing  502 , and is approximately parallel or substantially parallel to the top and bottom sides of housing  502 . Furthermore, and for one embodiment, each of the coil assembly  514 , the armature  516 , and the magnetic system of BA based valve  500  are between the membrane  506  and the bottom side of housing  502 . For one embodiment, the membrane  506  is approximately 7.5 mm by 3.9 mm. For one embodiment, the membrane  506  is a multi-part assembly comprising a main part of the membrane  506 , the valve flap  508 , and the hinge  510 . For one embodiment, the main part of the membrane  506  is made of one or more materials that do not move or vibrate in response to the movement of the drive pin  512 . For this embodiment, the valve flap  508  of the membrane  506  is made of one or more materials that move in compliance with the movement of the drive pin  512 . Furthermore, and for this embodiment, the hinge  510  can be at least as immovable as the main part of the membrane  506  to facilitate with the movement of the valve flap  508  by the drive pin  512 . In a first example, the main part of the membrane  506  and the hinge  510  are made of at least one of nickel or aluminum; and multi-layered with copper to immobilize those parts of the membrane  506 . In this first example, the valve flap  508  is not immobilized with copper. In a second example, the main part of the membrane  506  and the hinge  510  are made of at least one of nickel or aluminum; and a frame of copper is used to encase the main part of the membrane  506  and the hinge  510  so as to immobilize those parts of the membrane  506 . In this second example, the valve flap  508  is not encased in copper, and as a result, the valve flap  508  not immobilized. In the two preceding examples, the valve flap is not immobilized to enable its compliance with the movements of the drive pin  512 . 
     For one embodiment, the main part of the membrane  506  is made from at least one of Biaxially-oriented polyethylene terephthalate (hereinafter “BoPET”), aluminum, copper, nickel, or any other suitable material or alloy known in the art. For one embodiment, the valve flap  508  is made from BoPET, aluminum, copper, nickel, or any other suitable material or alloy known in the art. For one embodiment, the hinge  510  is made from BoPET, aluminum, copper, nickel, or any other suitable material or alloy known in the art. For one embodiment, each of the main part of the membrane  506  and the hinge  510  is formed using a metal forming process, e.g., electroforming, electroplating, etc. For one embodiment, the valve flap  508  is formed on the membrane  506  using an etching process, e.g. laser marking, mechanical engraving, chemical etching, etc. 
     For one embodiment, the valve flap  508  dictates the size of the membrane  506 , which includes the size of the main part of membrane  506  and the size of the hinge  510 . For one embodiment, the valve flap has a diameter that is between 1.5 mm and 2 mm. For one embodiment, the valve flap  508  is a substantially rectangular or oblong shape with a length of 4 mm and a width of 6 mm. For a first example, and for one embodiment, the valve flap has a cross-sectional area between 1 mm 2  and 3 mm 2 . For a second example, and for one embodiment, the valve flap  508  has a cross-sectional area between 1.75 mm 2  and 3.1 mm 2 . For one embodiment, the size of the valve flap  508  can affect the level of reduction of an occlusion effect and the ability of a listener to manipulate perceived audio transparency. For a first example, and for one embodiment, a valve flap  508  with a size of 1.75 mm 2  can assist with improved occlusion reduction. For a second example, and for one embodiment, a valve flap  508  with a size of 3.1 mm 2  minimum can assist with improved perception of audio transparency because the opened valve flap  508 A enables the BA based valve  500  to match open ear behavior, which occurs at sound frequencies that are approximately less than or equal to 1.0 kHz. For one embodiment, the shape of the valve flap  508  matches the cross sectional area of the connecting pathways to a listener&#39;s ear in a medial location and to the ambient environment in a lateral location to minimize acoustic reflections in the transmission line  520 . For one embodiment, the shape of the valve flap  508  can be substantially rectangular, substantially circular, substantially oblong, or any variation or combination thereof. For a further embodiment, the shape of the valve flap  508  is dictated by one or more design constraints. For example, the design constraints described herein, the design constraints associated with manufacturing processes, etc. 
     For one embodiment, the armature  516  is a U-shaped armature or an E-shaped armature, as is known in the art. For one embodiment, the armature  516  is modified U-shaped armature with a crimp or a dimple (hereinafter “dimple”)  532 , which is illustrated in  FIG.  5 A . The dimple  532  converts an arm of the armature  516  that is between the magnets  522 A-B into a movable arm of the armature  516 . As a result, the movable arm of the armature  516  can assist with the bi-stable operation of the armature  516  because the movable arm can move in compliance with one or more forces created by the coil assembly  514  and the magnets  522 A-B. For one embodiment, the dimple  532  is located anywhere on the movable arm of the armature  516  that is between the following two points: (i) a tangent point located at or near the beginning of the curved portion of the movable arm of the armature  516 ; and (ii) a point on the movable arm of the armature  516  that is closer to the drive pin  512  than the tangent point. For a first example, and for one embodiment, the dimple  532  is located anywhere within a portion  533  of the movable arm of the armature  516 , as illustrated in  FIG.  5 A . For a second example, and for one embodiment, the dimple  532  is located within the first twenty-five percent (25%) of the length of the movable arm, as measured from the tangent point located at or near the beginning of the curved portion of the movable arm of the armature  516 . For this embodiment, the dimple  532  can assist with reduction in a stiffness of the armature  516  so that the magnets  522 A-B can attract or repel the armature  516  easily. For one embodiment, the dimple  532  can be included in any type of U-shaped armature that is used in any of the embodiments of a BA based valve as described herein—e.g., any of the BA based valves described in connection with  FIGS.  5 A- 16   . The dimple  532  can also be included in any type of U-shaped armature that is used in any known acoustic driver—e.g., the acoustic driver  400  described above in connection with  FIG.  4   . 
     For one embodiment, the armature  516  is an E-shaped armature. For this embodiment, the E-shaped armature  516  can assist with mechanically centering the armature  516  between the magnets  522 A-B, which can enable bi-stable operation of the armature  516 . 
     For one embodiment, the thickness, material, and formation process of the armature  516  will be defined to meet an excursion range for which the armature  516  will travel in the air gap  530  so as to move or collapse the armature  516  to either one of magnets  522 A-B without causing damage or deformation to the armature  516 . For one embodiment, the excursion range is between +0.006 inches and −0.006 inches, i.e., the total excursion range is 0.012 inches. For one embodiment, the excursion range is between +0.008 inches and −0.008 inches, i.e., the total excursion range is 0.016 inches. For one embodiment, the total excursion range is at least 0.012 inches. For one embodiment, the total excursion range is at most 0.016 inches. For one embodiment, the air gap  530  is at least approximately 0.020 inches. For one embodiment, the air gap  530  is at most approximately 0.020 inches. For one embodiment, the thickness of the armature  516  is at least 0.004 inches. For one embodiment, the thickness of the armature  516  is at most 0.008 inches. For one embodiment, the armature  516  is formed from a material that is magnetically permeable, such as a soft magnetic material. For example, and for one embodiment, the armature  516  is formed from at least one of nickel, iron, or any other magnetically permeable material known in the art. For one embodiment, the armature  516  includes multiple layers of magnetically permeable materials. For one embodiment, the armature  516  is formed by at least one of stamping or annealing. 
     For one embodiment, at least one of the components of the magnetic assembly of BA based valve  500  (which includes the coil assembly  514 , the two magnets  522 A-B, the pole piece  524 , and the air gap  530 ) is formed from a material that is magnetically permeable, such as a soft magnetic material. For example, and for one embodiment, the pole piece  524  is formed from at least one of nickel, iron, or any other magnetically permeable material known in the art. For one embodiment, the pole piece is a multi-layer pole piece that has at least two layers of magnetically permeable materials. For one embodiment, at least part of the pole piece is formed by at least one of stamping, annealing, or metal injection molding. 
     For one embodiment, each of the magnets  522 A-B includes at least one of aluminum, nickel, cobalt, copper, titanium, or a rare earth magnet (e.g., a samarium-cobalt magnet, a neodymium magnet, etc.). For one embodiment, each of the magnets  522 A-B is designed to exhibit a low coercive force. For one embodiment, each of the magnets  522 A-B is designed to be easily demagnetized to balance the armature  516  between the magnets  522 A-B when necessary. For one embodiment, each of the magnets  522 A-B is designed according to standards developed by the Magnetic Materials Producers Association (hereinafter “MMPA”) and any other organizations that replaced or superseded the MMPA. Standards developed by the MMPA include, but are not limited to, the MMPA standard for Permanent Magnet Materials (MMPA 0100-00) and the MMPA Permanent Magnet Guidelines (MMPA PMG-88). For one embodiment, each of the magnets  522 A-B includes at least one of aluminum, nickel, or cobalt. For one embodiment, each of the magnets  522 A-B is an Alnico magnet. In a first example, and for one embodiment, each of the magnets  522 A-B is an Alnico 5-7 magnet, which is defined in the MMPA 0100-00 or the MMPA PMG-88. In a second example, and for one embodiment, each of the magnets  522 A-B is an Alnico 8 magnet, which is defined in the MMPA 0100-00 or the MMPA PMG-88. One advantage of the magnets  522 A-B being Alnico 5-7 magnets is that the magnets  522 A-B can be used for low reluctance circuits. One advantage of the magnets  522 A-B being Alnico 8 magnets is that the magnets  522 A-B can be used for high reluctance circuits. 
     For one embodiment, each of the terminal  518  and the connector  528  are formed from materials that enable electrical connections, as is known in the art. For one embodiment, the BA based valve  500  is included in an in-ear speaker. 
       FIG.  5 B  is a cross-sectional side view illustration of another embodiment of a BA based valve  525 . The BA based valve  525  is a modification of the BA based valve  500  of  FIG.  5 B  (which is described above in connection with  FIG.  5 A ). For the sake of brevity, only the differences between the BA based valve  525  and the BA based valve  500  (which is described above in connection with  FIG.  5 A ) are described below in connection with  FIG.  5 B . 
     One difference between the BA based valve  525  and the BA based valve  500  relates to the placement of the spout  504 C. In  FIG.  5 A , the spout  504 B is located on the rear side of housing  502 . In contrast, spout  504 C of  FIG.  5 B  is located on the bottom side of housing  502 . For one embodiment, the spout that is used for assisting with a reduction of an occlusion effect or manipulation of perceived audio transparency (e.g., the spout  504 B of  FIG.  5 A , the spout  504 C of  FIG.  5 B , etc.) can be located anywhere on the rear and bottom sides of housing  502 . 
     For one embodiment, the two spouts of the BA based valves  500  and  525  can be located anywhere on the housing  502 . For this embodiment, the membrane is substantially parallel to the top and bottom sides of the housing  502  and the two spouts are separated by the membrane  506 . For a first example, and for one embodiment, the spout  504  A of  FIGS.  5 A and  5 B  is located anywhere on the housing  502  between the membrane  506  and the top side of the housing  502 . In this example, and for this embodiment, the spout  504  B of  FIG.  5 A  or the spout  504 C of  FIG.  5 B  is located anywhere on the housing  502  between the membrane  506  and the bottom side of the housing  502 . In this way, the valve flap  508  can be enabled to assist with mitigation of an occlusion effect or with manipulation of perceived audio transparency. For one embodiment, the BA based valve  525  is included in an in-ear speaker. 
       FIG.  6 A  is a cross-sectional top view illustration of one embodiment of a membrane  600  that is included the BA receivers illustrated in  FIGS.  5 A- 5 B . For one embodiment, the membrane  600  is similar to or the same as membrane  506 , which is described above in connection with  FIGS.  5 A- 5 B . In the illustrated embodiment, the membrane  600  includes the valve flap  508  in the open position  508 A and the closed position  508 B, the drive pin  512 , a primary membrane  604 , a membrane frame  606 , and an adhesive  602  that is used to secure the drive pin  512  to the valve flap  508 . For one embodiment, the primary membrane  604  comprises the main part of the membrane  600  and the hinge (not shown), as described above in connection with  FIGS.  5 A- 5 B . For one embodiment, each of the valve flap  508 , the primary membrane  604 , and the membrane frame  606  is formed in accordance with the description provided above in connection at least one of  FIGS.  5 A- 5 B . For example, and for one embodiment, each of the valve flap  508  and the primary membrane  604  are made of at least one of nickel or aluminum. In this example, the primary membrane  604  is multi-layered with copper to immobilize the primary membrane  604 , while the membrane frame  606  is formed from copper and used to encase the primary membrane  604  so as to further immobilize the primary membrane  604 . Furthermore, and in this example, the valve flap  508  is not immobilized with copper, as described above in at least one of  FIGS.  5 A- 5 B . 
       FIG.  6 B  is a cross-sectional side view illustration of the membrane illustrated in  FIG.  6 A . For one embodiment, the adhesive  602  is used to secure the drive pin  512  to the valve flap  508 . For one embodiment, the adhesive  602  is a polymer material, e.g., a compressed polymer material. For one embodiment, the adhesive  602  secures the drive pin  512  to the valve flap  508  by bonding or other processes known in the art. For one embodiment, a hole is formed in the valve flap  508  to enable the drive pin  512  to be secured to the valve flap  508  using the adhesive  602  or other securing mechanisms known in the art. It is to be appreciated that use of the adhesive  602  to secure the drive pin  512  to the valve flap  508  is merely exemplary. It is to be appreciated that other securing techniques (as known in the art) that are not disclosed herein can be used to secure the drive pin  512  to the valve flap  508 . 
       FIG.  7 A  is a block diagram side view illustration of one embodiment of a bi-stable state  700  of at least one of the BA based valves  500  and  525  illustrated in  FIGS.  5 A and  5 B , respectively. In some embodiments of the BA based valves  500  and  525 , an electrical input signal  702  is applied (in the form of a positive current, e.g., between +1 mA and +3 mA) to the coil assembly  514 . For one embodiment, the coil assembly  514  creates a magnetic flux in response to the applied current and the magnetic flux moves the armature  516  upwards towards upper magnet  522 A. For one embodiment, the upper magnet  522 A has a magnetic field strength that attracts the upward moving armature  516  and causes the armature  516  to remain in direct contact with the upper magnet  522 A. For this embodiment, the drive pin  512  actuates the valve flap  508  into the open position  508 A as the armature  516  moves into direct contact with the upper magnet  522 A. At this point, the current (electrical input signal  702 ) through the coil assembly  514  can now be reduced, e.g., down to zero, by a control circuit (not shown) that may be incorporated into the BA based valve  500 ,  525 . In one embodiment, the control circuit accepts a continuous, low power logic control signal via the terminal  518  and connector  528 , where the signal may have two stable states, one that commands an open state for the valve flap  508 , and another that commands a closed state for the valve flap  508 ; this logic control signal may originate from an external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.) The control circuit converts the logic control signal into a short current pulse (electrical input signal  702 ) having the correct polarity as described below, to operate the coil assembly  514 . For one embodiment, the control circuit can also include logic for receiving one or more input signals from the one or more sensors, as described above in connection with at least one of  FIGS.  5 A- 5 B . 
       FIG.  7 B  is a block diagram side view illustration of one embodiment of another bi-stable state  725  of at least one of the BA based valves  500  and  525  illustrated in  FIGS.  5 A and  5 B , respectively. For some embodiments of the BA based valves  500  and  525 , an electrical input signal  704  is applied (in the form of a negative current, e.g., between −1 mA and −3 mA) to the coil assembly  514 . For one embodiment, the coil assembly  514  creates a magnetic flux in response to the applied current and the magnetic flux moves the armature  516  downwards towards the lower magnet  522 B. For one embodiment, the lower magnet  522 B has a magnetic field strength that attracts the downward moving armature  516  and causes the armature  516  to remain in direct contact with the lower magnet  522 B. For this embodiment, the drive pin  512  actuates the valve flap  508  into the closed position  508 B as the armature  516  moves into direct contact with the lower magnet  522 B. At this point, the coil current (electrical input signal  704 ) can be reduced from its activation level, down to for example zero, by the control circuit that is incorporated into the BA based valves  500  and  525 , as described above in connection with  FIG.  7 A . 
       FIG.  8    is a cross-sectional side view illustration of one embodiment of a driver assembly  800  of the in-ear speaker, that includes the BA based valve  500  described above in connection with  FIG.  5 A , and the acoustic driver  400  described above in connection with  FIG.  4   . The illustrated embodiment of the driver assembly  800  is a combination of the BA based valve  500  and the acoustic driver  400  within a housing  802 ; however other embodiments are not so limited. For example, and for one embodiment, the driver assembly  800  includes at least one BA based valve  500  and at least one of (i) one or more BA receivers known in the art; or (ii) one or more acoustic drivers that are not BA receivers. For one embodiment, the housing  802  includes a first spout  804 A that is to deliver sound that is output/generated by the acoustic drivers of the driver assembly  800  to an ear canal or to an ambient environment. For one embodiment, the housing  802  includes at least one second spout  504 B that is to deliver unwanted sound created by an occlusion effect away from an ear canal, as described above in connection with  FIG.  5 A . For the sake of brevity, only those features, components, or characteristics that have not been described above in connection with  FIGS.  1 A- 7 B  will be described below in connection with  FIG.  8   . 
     The driver assembly  800  includes a housing  802 . For one embodiment, the housing  802  holds, encases, or is attached to one or more of the components of the BA receivers in the driver assembly  800 . Furthermore, and for one embodiment, the housing  802  includes a top side, a bottom side, a front side, and a rear side. For one embodiment, the front side of the housing  802  is substantially parallel to the rear side of the housing  802 . For one embodiment, the top side of the housing  802  is substantially parallel to the bottom side of the housing  802 . When the driver assembly  800  is part of an in-ear speaker that is placed in a user&#39;s ear, the rear side of the housing  802  is further away from the user&#39;s ear canal than the front side of the housing  802  and the rear side of the housing  802  is closer to an ambient environment than the front side of the housing  802 . 
     For one embodiment, the driver assembly  800  includes two spouts  804 A and  504 B, which may be formed on or coupled to the housing  802  as is known in the art. For one embodiment, the spout  804 A performs the functions of the spout  504 A of the BA based valve  500  and the functions of the spout  404  of the acoustic driver  400 . The spouts  504 A- 504 B are described above in connection with  FIGS.  5 A- 5 B . The spout  404  is described above in connection with  FIG.  4   . 
     In the illustrated embodiment of the driver assembly  800 , the spout  804 A is formed on or coupled to the front side of the housing  802 ; the spout  504 B, a terminal  418 , a terminal  518  are formed on or attached to the rear side of the housing  802 ; the spout  804 A is equally close to the top and bottom sides of the housing  802 ; the spout  504 B is farther from the top side of the housing  802 ; the spout  504 B is closer to the bottom side of the housing  802 ; and the terminal  418  is closer to the top side of the housing  802 . 
     For one embodiment, the driver assembly  800  combines an ability of the acoustic driver  400  to create sounds that are delivered to a listener&#39;s ear with an ability of the BA based valve  500  to reduce an occlusion effect and an ability of the BA based valve  500  to enable manipulation of perceived audio transparency. For one embodiment, the membrane  406  creates sounds based on an audio signal input or provided as coil current, to the coil assembly  414 , as described above in connection with  FIG.  4   . For one embodiment, the sounds created by the membrane  406  are emitted through the spout  804 A into an ear of a listener or an ambient environment. For one embodiment, the valve flap  508  of the membrane  506 , the spout  804 A, and the spout  504 B are used to release at least some of the amplified or echo-like sounds that result from an occlusion effect in the listener&#39;s ear, as described above in at least one of  FIGS.  5 A- 7 B . For one embodiment, the valve flap  508  of the membrane  506 , the spout  804 A, and the spout  504 B are used to enable manipulation of perceived audio transparency, as described above in at least one of  FIGS.  5 A- 7 B . The spout  804 A is thus shared as both a primary sound output port for an acoustic driver (producing sound in accordance with an audio signal received at terminal  418 ) and as a release port for releasing (into the ambient environment through the spout  504 B) the pressure of the amplified or echo-like sounds in the ear canal. For one embodiment, the reduction of the occlusion effect and the manipulation of the perceived audio transparency is based on one or more sensors, e.g., the sensors described above in at least one or  FIGS.  5 A- 7 B . For one embodiment, the driver assembly  800  is included in an in-ear speaker. 
       FIG.  9    is a cross-sectional side view illustration of one embodiment of a driver assembly  900  that includes the BA based valve  525  described above in connection with  FIG.  5 B  and the acoustic driver  400  described above in connection with  FIG.  4   . For one embodiment, the driver assembly  900  is a modification of the driver assembly  800  described above in  FIG.  8   . The illustrated embodiment of driver assembly  900  is a combination of the BA based valve  525  and the acoustic driver  400  in the housing  802 ; however other embodiments are not so limited. For example, and for one embodiment, the driver assembly  900  includes at least one BA based valve  525  and at least one of (i) one or more BA receivers known in the art; or (ii) one or more acoustic drivers that are not BA receivers. For the illustrated embodiment, the housing  802  includes a first spout  804 A and a second spout  504 C. The spout  804 A is described above in connection with  FIG.  8    and the spout  504 C is described above in connection with  FIG.  5 B . For one embodiment, the driver assembly  900  is included in an in-ear speaker. For the sake of brevity, reference is made to the descriptions provided above in connection with at least one of  FIG.  4 ,  5 A- 5 B , or  8 . 
       FIG.  10 A  is a cross-sectional side view illustration of yet another embodiment of the venting or acoustic pass valve  210 , as a BA based valve  1000 . BA based valve  1000  is a modification of the BA based valve  500  (which is described above in connection with  FIG.  5 A ). For the sake of brevity, only the differences between the BA based valve  1000  and the BA based valve  500  (which is described above) will be described below in connection with  FIG.  10 A . 
     One difference between the BA based valve  1000  and the BA based valve  500  relates to the presence of the membrane  1006  including a detachable valve flap  1008  and without the hinge  510 . For one embodiment, the detachable valve flap  1008  of  FIG.  10 A  differs from the valve flap  508  of  FIG.  5 A  because at least one end of the valve flap  508  of  FIG.  5 A  remains coupled to the membrane  506  of  FIG.  5 A , while the other end of the valve flap  508  is lifted by the driver pin  512  to open the valve flap  508 . In contrast, the entirety of the detachable valve flap  1008  of  FIG.  10 A  is lifted by the drive pin  512  so that the valve flap  1008  is completely detached from the membrane  1006 . Furthermore, there is no hinge  510  in the membrane  1006 , which can reduce the number of components used to make the membrane. For one embodiment, the detachable valve flap  1008  of membrane  1006  is completely detached from the membrane  1006  into an open position  1008 A and re-attached to the membrane  1006  into a closed position (not shown) based on a movement of the drive pin  512 . For one embodiment, the BA based valve  1000  is included in an in-ear speaker. 
       FIG.  10 B  is a cross-sectional side view illustration of one additional embodiment of the valve  210 , as a BA based valve  1025 . BA based valve  1025  is a modification of BA based valve  525  (which is described above in connection with  FIG.  5 B ). For the sake of brevity, only the differences between the BA based valve  1025  and the BA based valve  525  (which is described above) will be described below in connection with  FIG.  10 B . 
     One difference between the BA based valve  1025  and the BA based valve  525  relates to the presence of the membrane  1006  (including detachable valve flap  1008  without a hinge  510 ). The differences between the membrane  1006  and the membrane  506  are described above in connection with  FIG.  10 A . For one embodiment, the BA based valve  1025  is included in an in-ear speaker. 
       FIG.  11 A  is a cross-sectional top view illustration of one embodiment of a membrane  1100  that is included in at least one of the BA based valves  1000  and  1025  illustrated in  FIGS.  10 A and  10 B , respectively. For one embodiment, the membrane  1100  is a modification of membrane  600  described above in connection with  FIG.  6 A . One difference between the membrane  1100  and the membrane  600  relates to the presence of the detachable valve flap  1008  without the hinge  510 . The differences between the membrane  1006  and the membrane  506  are described above in connection with  FIG.  10 A . For one embodiment, membrane  1100  is similar to or the same as membrane  1006 , which is described above in connection with  FIGS.  10 A- 10 B . For the illustrated embodiment, the membrane  1100  includes the detachable valve flap  1008  in the open position  1008 A, the drive pin  512 , a primary membrane  604 , a membrane frame  606 , and an adhesive  602  that is used to secure the drive pin  512  to the detachable valve flap  1008 . Each of these components is described above in connection with at least one of  FIGS.  6 A- 10 B . For one embodiment, the primary membrane  604  comprises the main part of the membrane without a hinge. For one embodiment, each of the valve flap  508 , the primary membrane  604 , and the membrane frame  606  is formed in accordance with the description provided above in connection  FIGS.  5 A- 5 B  except that there is no hinge. 
       FIG.  11 B  is a cross-sectional side view illustration of the membrane illustrated in  FIG.  11 A . The membrane illustrated by  FIG.  11 B  is a modification of the membrane described above in connection with  FIG.  6 B . One difference between the membrane illustrated by  FIG.  11 B  and the membrane described above in connection with  FIG.  6 B  relates to the presence of the detachable valve flap  1008  without the hinge  510 . The differences between the membrane  1006  and the membrane  506  are described above in connection with  FIG.  10 A . For the sake of brevity, reference is made to the descriptions provided above in connection with at least one of  FIGS.  6 B and  10 A- 11 A . 
       FIG.  12 A  is a block diagram side view illustration of one embodiment of a bi-stable operation  1200  of at least one of the BA based valves  1000  and  1025  illustrated in  FIGS.  10 A and  10 B , respectively. The bi-stable operation  1200  is a modification of the bi-stable operation  700  described above in connection with  FIG.  7 A . One difference between the bi-stable operation  1200  and the bi-stable operation  700  described above in connection with  FIG.  7 A  relates to the presence of the detachable valve flap  1008  without a hinge  510 . The differences between the detachable valve flap  1008  and the valve flap  508  are described above in connection with  FIG.  10 A . For the sake of brevity, reference is made to the descriptions above in connection with  FIGS.  7 A and  10 A- 11 B . 
       FIG.  12 B  is a block diagram side view illustration of one embodiment of another bi-stable operation  1225  of at least one of the BA based valves  1000  and  1025  illustrated in  FIGS.  10 A and  10 B , respectively. The bi-stable operation  1225  is a modification of the bi-stable operation  725  described above in connection with  FIG.  7 B . One difference between the bi-stable operation  1225  and the bi-stable operation  725  described above in connection with  FIG.  7 B  relates to the presence of the detachable valve flap  1008  without a hinge  510 . The differences between the detachable valve flap  1008  and the valve flap  508  are described above in connection with  FIG.  10 A . For the sake of brevity, reference is made to the descriptions above in connection with  FIGS.  7 B and  10 A- 11 B . 
       FIG.  13    is a cross-sectional side view illustration of one embodiment of a driver assembly  1300  that includes the BA based valve  1000  described above in connection with in  FIG.  10 A  and the acoustic driver  400  described above in connection with  FIG.  4   . For one embodiment, the driver assembly  1300  is a modification of the driver assembly  800 , which is described above in connection with  FIG.  8   . One difference between the driver assembly  1300  and the driver assembly  800  described above in connection with  FIG.  8    relates to the presence of the detachable valve flap  1008  without a hinge  510 . The differences between the detachable valve flap  1008  and the valve flap  508  are described above in connection with  FIG.  10 A . The illustrated embodiment of driver assembly  1300  is a combination of one embodiment of the BA based valve  1000  and the acoustic driver  400  in the housing  802 ; however other embodiments are not so limited. For example, and for one embodiment, the driver assembly  1300  includes at least one BA based valve  1000  and at least one of (i) one or more BA receivers known in the art; or (ii) one or more acoustic drivers that are not BA receivers. For one embodiment, the driver assembly  1300  is included in an in-ear speaker. For the sake of brevity, reference is made to the descriptions provided above in connection with at least one of  FIG.  8  or  10 A- 12 B . 
       FIG.  14    is a cross-sectional side view illustration of one embodiment of a driver assembly  1400  that includes the BA based valve  1025  described above in connection with  FIG.  10 B  and the acoustic driver  400  described above in connection with  FIG.  4   . For one embodiment, the driver assembly  1400  is a modification of the driver assembly  900  described above in connection with  FIG.  9   . One difference between the driver assembly  1400  and the driver assembly  900  described above in connection with  FIG.  9    relates to the presence of the detachable valve flap  1008  without a hinge  510 . The differences between the detachable valve flap  1008  and the valve flap  508  are described above in connection with  FIG.  10 A . The illustrated embodiment of driver assembly  1400  is a combination of one embodiment of the BA based valve  1025  and the acoustic driver  400  in the housing  802 ; however other embodiments are not so limited. For example, and for one embodiment, the driver assembly  1400  includes at least one BA based valve  1025  and at least one of (i) one or more BA receivers known in the art; or (ii) one or more acoustic drivers that are not BA receivers. For one embodiment, the driver assembly  1400  is included in an in-ear speaker. For the sake of brevity, reference is made to the descriptions provided above in connection with at least of  FIG.  4 ,  10 B , or  13 . 
       FIG.  15    is a cross-sectional side view illustration of yet another embodiment of a driver assembly  1500  that includes the BA based valve  500  described above in connection with in  FIG.  5 A  and the acoustic driver  400  described above in connection with  FIG.  4   . For one embodiment, the driver assembly  1500  is a modification of the driver assembly  800 , which is described above in connection with  FIG.  8   . One difference between the driver assembly  1500  and the driver assembly  800  (which is described above) is that, in the housing  1502  of the driver assembly  1500 , the BA based valve  500  and the acoustic driver  400  are adjacently next to each other in an x-direction or a y-direction. This embodiment of the driver assembly  1600  can enable formation of driver assemblies with predetermined or specified z-heights. Accordingly, for one embodiment, the use of the housing  1502  to create the driver assembly  1500  may allow for an overall reduction of the z-height in size-critical applications. 
     The illustrated embodiment of the driver assembly  1500  is a combination of the BA based valve  500  and the acoustic driver  400  within a housing  1502 ; however other embodiments are not so limited. For example, and for one embodiment, the driver assembly  1500  includes at least one BA based valve that is described herein (e.g., BA based valve  500  or  525 ) and at least one of (i) one or more BA receivers known in the art; or (ii) one or more acoustic drivers that are not BA receivers. For one embodiment, the housing  1502  includes a first spout  1504 A that is to deliver sound that is output/generated by the acoustic drivers of the driver assembly  1500  to an ear canal or to an ambient environment. For one embodiment, the first spout  1504 A is similar to or the same as the spout  804 A, which is described above in connection with  FIG.  8 A . For one embodiment, the housing  1502  includes at least one second spout  1504 B that is to deliver unwanted sound created by an occlusion effect away from a listener&#39;s ear. For one embodiment, the second spout  1504 B is similar to or the same as the spout  504 B, which is described above in connection with  FIG.  5 A . For one embodiment, the driver assembly  1500  is included in an in-ear speaker. 
       FIG.  16    is a cross-sectional side view illustration of another embodiment of a driver assembly  1600  that includes the BA based valve  1000  described above in connection with in  FIG.  10 A  and the acoustic driver  400  described above in connection with  FIG.  4   . For one embodiment, the driver assembly  1600  is a modification of the driver assembly  1300 , which is described above in connection with  FIG.  13   . One difference between the driver assembly  1600  and the driver assembly  1300  (which is described above) is that, in the housing  1502  of the driver assembly  1600 , the BA based valve  1000  and the acoustic driver  400  are adjacently next to each other in an x-direction or a y-direction. This embodiment of the driver assembly  1600  can enable formation of driver assemblies with predetermined or specified z-heights. Accordingly, for one embodiment, the use of the housing  1502  to create the driver assembly  1600  may allow for an overall reduction of the z-height in applications that are size-critical. 
     The illustrated embodiment of the driver assembly  1600  is a combination of the BA based valve  1000  and the acoustic driver  400  within a housing  1502 ; however other embodiments are not so limited. For example, and for one embodiment, the driver assembly  1600  includes at least one BA based valve that is described herein (e.g., BA based valve  1000  or  1025 ) and at least one of (i) one or more BA receivers known in the art; or (ii) one or more acoustic drivers that are not BA receivers. For one embodiment, the housing  1502  of the driver assembly  1600  includes a first spout  1504 A that is to deliver sound that is output/generated by the acoustic drivers of the driver assembly  1500  to an ear canal or to an ambient environment. For one embodiment, the first spout  1504 A is similar to or the same as the spout  804 A, which is described above in connection with  FIG.  8 A . For one embodiment, the housing  1502  of the driver assembly  1600  includes at least one second spout  1504 B that is to deliver unwanted sound created by an occlusion effect away from a listener&#39;s ear. For one embodiment, the second spout  1504 B is similar to or the same as the spout  504 B, which is described above in connection with  FIG.  5 A . For one embodiment, the driver assembly  1600  is included in an in-ear speaker. 
     Additional Features for an Active Vent System 
       FIG.  17    illustrates how at least one embodiment of the venting or acoustic pass valve  210  described above in connection with at least one of  FIGS.  2  and  5 A- 16    can be used as part of an active vent system  1700  in accordance with one embodiment. The active vent system  1700  includes the in-ear speaker  206  which contains the valve  210 , different embodiments of which were described above in connection with  FIGS.  2 ,  5 A- 16   . For the sake of brevity, only the differences between the features of  FIG.  2    and  FIG.  17    will be described below in connection with  FIG.  17   . 
     As explained above in connection with at least one of  FIGS.  2  and  5 A- 16   , at least one embodiment of the BA based valve  210  includes at least two spouts, a membrane (including a valve flap and a hinge), an armature, a coil assembly, two magnets, a pole piece, and an air gap. For example, and for one embodiment, the valve flap of the membrane can be in an open position or a closed position to assist with reduction or elimination of amplified or echo-like sounds created by an occlusion effect, as well as, manipulation of perceived audio transparency. 
     For one embodiment, the active vent system  1700  is an acoustic system that couples an otherwise sealed ear canal to an external ambient environment (outside of an ear or an electronic device) using a pathway  1701 . For one embodiment, the pathway  1701  is a network of volumes that include the BA based valve  210 . For example, and for one embodiment, the active vent system  1700  requires a minimal pathway  1701  (i.e., a minimal amount of volumes that make up the pathway  1701 ) that includes a sealed ear canal volume, the BA based valve  210 , and a volume representing the external ambient environment outside of an ear or an electronic device. 
     For one embodiment, a volume of the pathway  1701  is a dynamic air pressure confined within a specified three dimensional space, where this volume is represented as an acoustic impedance. Depending on the geometry of the volume, this acoustic impedance can behave like a compliance, inertance, (also known as “acoustic mass”), or a combination of both. The specified three dimensional space can be expressed in a tangible form as a tubular structure, a cylindrical structure, or any other type of structure with a defined boundary. 
     For one embodiment, the geometry of the pathway  1701  determines an overall effectiveness of the ability of the system  1700  to assist with reduction or elimination of amplified or echo-like sounds created by an occlusion effect, as well as, manipulation of perceived audio transparency. For example, the pathway  1701  can have a predetermined geometry that assists with reducing an occlusion effect and also with reducing any unwanted energy that builds up in the ear canal due to activity (e.g. running, footfalls, chewing, etc.) Each volume can be designed with a constant cross section and can resemble a structure of various cross section shapes. For one embodiment, the pathway  1701  includes at least three volumes  1703 ,  1705 , and  1707 . The first volume  1703  can be embodied in a tubular structure, a cylindrical structure, or any other structure with a defined boundary (not shown) that connects the BA based valve  210  of the in-ear speaker  206  to the ambient environment outside the ear  102 . The second volume  1705  can be embodied in a tubular structure, a cylindrical structure, or any other structure with a defined boundary (not shown) that connects the BA based valve  210  of the in-ear speaker  206  to the ear canal  104  inside the ear  102 . The third volume  1707  can be embodied as the BA based valve  210  itself. 
     For an embodiment, the centerline of the pathway  1701  could be circuitous, rectilinear, or any combination of having a simple or complex direction. Furthermore, the BA based valve  210  of the in-ear speaker  206  can be placed anywhere along the pathway  1701 , either closer to the ear canal  104  or closer to the ambient environment outside the ear  102 . For a specific embodiment, the valve flap of the BA based valve  210  is placed along the centerline of the pathway  1701 . 
     For one embodiment, each of the volumes  1703 ,  1705 , and  1707  of the pathway  1701  is quantified in terms of that specific volume&#39;s acoustic impedance (also known as acoustic mass). In this way, the entire pathway  1701  can be quantified using an overall acoustic impedance (Z TOTAL ). The use of acoustic impedance to describe each of the volumes  1703 ,  1705 , and  1707  of the pathway  1701  is due to the fact that the presence or absence of acoustic impedance dominates the behavior and effectiveness of the active vent system  1700 . The volume  1703  (which can be embodied in a structure that is not shown in  FIG.  17   ) is quantified by its acoustic impedance Z AMB , which represents the acoustic impedance of the structure connecting the BA based valve  210  to the ambient environment outside the ear  102 . The volume  1705  (which can be embodied in a structure that is not shown in  FIG.  17   ) is quantified by its acoustic impedance Z EAR , which represents the acoustic impedance of the structure connecting the BA based valve  210  to the ear canal  104  inside the ear  102 . The volume  1707  is quantified by its acoustic impedance Z BA , which represents the acoustic impedance in the BA based valve  210  itself. For some embodiments, Z BA  is considered to be negligible. For other embodiments, Z BA  is a factor in the overall acoustic impedance (Z TOTAL ). 
     For one embodiment, and with regard to the pathway  1701 , the formula for overall acoustic impedance (Z TOTAL ) is as follows:
 
 Z   TOTAL   =Z   AMB   +Z   BA   +Z   EAR  
 
     For one embodiment, the overall acoustic impedance (Z TOTAL ) is at least 500 Kg/m 4 . For one embodiment, the overall acoustic impedance (Z TOTAL ) is at most 800,000 Kg/m 4 . The concept of acoustic impedance or acoustic mass is well known to those skilled in the art, so a derivation and calculations for the ranges are not provided here. 
     A Hybrid Transparency System 
       FIG.  18    is an illustration of an in-ear speaker  1806 , which is configured as a hybrid audio transparency system in accordance with one embodiment. For one embodiment, the in-ear speaker  1806  assists with enabling a user of the in-ear speaker  1806  to achieve (i) isolation from sounds  214  in the ambient environment, by preventing those sounds  214  from entering the user&#39;s ear canal  104  using the combination of passive ear canal sealing and closing of the valve  210 ; and (ii) perception of audio transparency by enabling delivery of the sounds  214  from the ambient environment to the ear canal  104  even while the ear canal is sealed, via the combination of the opening of the valve  210  and activation of an ambient sound augmentation system  1801 . In this way, the in-ear speaker  1806  is a hybrid audio transparency system. It should be noted that the description refers to the valve  210  generically, in that venting or acoustic pass valves other than BA based valves can be used, including for example micro electromechanical system (MEMS)-based valves. 
     The in-ear speaker  1806  includes a user content sound system to receive a user content audio signal, being a recorded audio program signal or a downlink audio signal of a phone call, and convert the user content audio signal into sound for delivery into an ear canal that is sealed by the in-ear speaker. In a simple form, the user content sound system may consist of an electro-acoustic transducer (speaker driver) installed within the housing of the in-ear speaker, with a wired audio connection to an external device from which the user content audio signal is received and that directly drives the signal input of the speaker driver. In other embodiments, the user content sound system may include an audio amplifier within the housing of the in-ear speaker  1806 , digital audio signal processing (enhancement) capability, and a wireless digital communication interface through which the user content audio signal may be wirelessly received from some external device. 
     The in-ear speaker  1806  also includes the valve  210  which may be similar to or the same as any of the valves  210  described above in connection with  FIGS.  1 - 17   . A processor  1803  can trigger an opening or closing of the valve  210 . Processor  1803  may represent a single microprocessor or multiple microprocessors. Processor  1803 , which may be a low power multi-core processor such as an ultra-low voltage processor, may act as a main processing unit and central hub for communication with the various components of the in-ear speaker  1806  (including the user content audio system.) Processor  1803  is to execute instructions stored in memory (or is programmed), for performing the operations discussed herein in connection with at least one of  FIGS.  18 - 22   . The processor  1803  may be configured to control or coordinate a functioning of the in-ear speaker  1806 , including a functioning of the in-ear speaker  1806  as a hybrid audio transparency system. For one embodiment, the processor  1803  is located outside of the housing of the in-ear speaker, as part of an external data processing system (not shown) that is communicatively coupled to the in-ear speaker  1806  via a wired or a wireless digital communication interface, such as one that is shared by the user content sound system introduced above. For one embodiment, this external data processing system can be part of an external electronic device as described above in connection with at least  FIG.  5 A . 
     The in-speaker  1806  also has a sound augmentation system  1801 . The sound augmentation system  1801  includes an external microphone  1802 , whose output signal is coupled to the processor  1803 . The term “external” is used here to differentiate between the microphone  1802  and another microphone  2002 , where the latter as described below is designed to pick up sound within the ear canal. The sound augmentation system  1801  uses the external microphone  1802  to electrically pick up sound  214  from the ambient environment (not from the ear canal). This ambient sound is then reproduced into the ear canal  104  for absorption by the eardrum  112 , using an acoustic (speaker) driver in the in-ear speaker  1806  (e.g., one that is shared with the user content sound system). The sound  214  is picked up by the external microphone  1802 , converted into an electrical audio signal, processed by the processor  1803 , and then converted back into acoustic form as delivered into the ear canal  104 . For one embodiment, the processor  1803  also implements an equalizer to digitally adjust a frequency component of the sound that has been picked up by the external microphone  1802 . For one embodiment, these adjustments are made to provide the reproduced version of the sound  214  with characteristics that assist with enabling a user of the in-ear speaker to perceive the sound  214  as if there was no in-ear speaker  1806  sealing the ear  102  (the concept of audio transparency). 
     Referring briefly to  FIG.  19   , a chart  1900  is illustrated to show in part how the sound augmentation system works. The processor  1803  adjusts ( 1903 ) the audio signal picked up by the external microphone (ambient sound signal) in order to provide the audio signal (that will be converted into sound) with one or more characteristics that assist with enabling a user of the in-ear speaker to perceive the sound  214  as if there was no in-ear speaker  1806  sealing the ear  102 . As shown in  FIG.  19   , the curve  1901  represents the sound pressure losses in decibels (dB) associated with sealing the ear canal (hereinafter “insertion losses”), as a function of frequency. The curve  1902  represents the sound pressure in an unsealed ear canal that enables a user of the in-ear speaker  1806  to perceive the sounds  214  comfortably. For one embodiment, the processor  1803  implements an equalizer that adjusts  1903  the frequency components (gains) of the sound  214  that is picked up by the microphone  1802 . As shown in  FIG.  19   , the equalizer adjusts  1903  the gains at certain frequencies of the ambient audio signal, to compensate for the insertion losses, so as to give the processed, ambient audio signal effectively a zero decibel (dB) insertion loss. 
     For one embodiment, the processor  1803  can activate the sound augmentation system  1801  (to reproduce the sounds  214  of the ambient environment as the processed, ambient audio signal) in response to or whenever the valve  210  is being opened to promote a hybrid, audio transparency approach; it may then deactivate the sound augmentation system when the valve  210  is being closed to achieve isolation from the sounds  214  in the ambient environment. 
     For one embodiment, one or more of the control signals that cause the opening or closing of the valve  210  can be based on one or more measurements of one or more sensors (not shown) and based on an operating state of an external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.) that is using or electrically connected to the in-ear speaker  1806  to generate user content sound. For example, and for one embodiment, the one or more sensors can include at least one of an accelerometer, a sound sensor, a barometric sensor, an image sensor, a proximity sensor, an ambient light sensor, a vibration sensor, a gyroscopic sensor, a compass, a barometer, a magnetometer, or any other sensor whose purpose is to detect a characteristic of one or more environs. For one embodiment, the one or more control signals are applied to the coil assembly  514  and are based on one or more measurements of the one or more sensors. The one or more sensors may be included as part of the valve  210 , as part of the in-ear speaker  1806  that includes the valve  210 , or within the housing of an external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.) that is communicatively coupled to the in-ear speaker  1806  and provides the input user content audio signal to the in-ear speaker  1806 . 
     For one embodiment, the one or more sensors are coupled to logic (not shown) that determines, based on one or more measurements of the one or more sensors, when to activate the control signals that cause the opening or closing of the valve  210 . Furthermore, in response to the logic&#39;s determination that the valve  210  should be opened, the processor  1803  activates or operates the sound augmentation system  1801  as described above in connection with  FIG.  18   . 
     For one embodiment, a software component on an external electronic device (e.g., a smartphone, a computer, a wearable computer system, etc.) that is communicatively coupled to the in-ear speaker  1806  can analyze and/or gather data provided to or received by one or more software applications (e.g., an atmospheric pressure monitoring application, a weather monitoring application, etc.) that are running on the external electronic device. For one embodiment, based on the analyzed and/or gathered data, the software component determines whether to open or close the valve  210 . In response to the opening of the valve  210 , the processor  1803  can activate or operate the sound augmentation system  1801  as described above in connection with  FIG.  18   . 
     For one embodiment, the processor  1803  operates, in conjunction with the examples and embodiments described above in connection with  FIG.  5 A , to combine use of the valve  210  with the sound augmentation system  1801 . In each of those examples and/or embodiments, the processor  1803  operates the sound augmentation system  1801  as described above in connection with  FIG.  18    in response to the valve  210  being opened. Other examples and/or embodiments are also possible. It is to be appreciated that the immediately preceding examples are merely for illustration and are not intended to be limiting. This is because there are numerous types of sensors and ways in which the numerous types of sensors can be used and/or combined to operate the sound augmentation system  1801  (in response to an opening or closing of the valve  210 .) It is also to be appreciated that one or more of the examples and/or embodiments described above can be combined or practiced without all of the details set forth in the examples and/or embodiments described above. 
     For one embodiment, the logic that determines, based on one or more measurements of the one or more sensors, when one or more of the control signals that cause the opening or closing of the valve  210  are activated, can be manually overridden by the listener, to open or close the valve  210  when the listener chooses. For this embodiment, and in response to the opening of the valve  210  when there is a listener override, the processor  1803  activates the sound augmentation system  1801  as described above in connection with  FIG.  18   . In one embodiment, an external electronic device (which is electrically, that is wirelessly or via a wire link, connected to the in-ear speaker  1806  that includes the valve  210 ) can include one or more input devices that enable a listener to provide an input (as an override by the listener) that causes the logic to provide the control signal that causes the valve  210  to open. For this example, the processor  1803  also responds by operating the sound augmentation system  1801  as described above in connection with  FIG.  18    (in response to the valve  210  being opened.) For one embodiment, the external electronic device may be include, but is not limited to, the in-ear speaker  1806  that includes the valve  210 , but it may alternatively be a smartphone, a tablet computer, or a wearable computer system. 
     The use of the combination of the valve  210  and the sound augmentation system  1801  can assist in enabling the listener (wearer) of the in-ear speaker  1806  to improve his perception of audio transparency, by enabling effectively a delivery of the sound  214  from the ambient environment to the ear canal  104  via a combination of both the valve  210  and the sound augmentation system  1801 . 
     For one embodiment, the in-ear speaker  1806  can also include an active noise control or acoustic noise cancellation (ANC) system (not shown) comprised of an acoustic driver, an error microphone (not shown) and the processor  1803 , that work together to perform acoustic noise cancellation in order to reduce the occlusion effect (as explained earlier). The use of a processor and an error microphone for ANC is known so it is not discussed in detail, but in one embodiment, the ANC system can, via the error microphone, assist with controlling the adaptation of anti-noise (or anti-phase) that is acoustically combined with unwanted sound inside the ear canal, to cancel out any unwanted sounds (e.g., sounds from the ambient environment that may have leaked into the ear canal, or occlusion effect sounds produced in the ear canal). In this way, the ANC system can assist—in combination with the valve  210  and the sound augmentation system  1801 —with improving isolation from the sounds  214  in the ambient environment, by preventing those sounds  214  that have leaked into the user&#39;s ear canal  104  from being perceived by the user. For one embodiment, the ANC system is activated or operated to reduce the occlusion effect (as explained above), only in response to a closing of the valve  210 ; in one embodiment, the ANC system is then deactivated upon the valve  210  being opened. 
       FIG.  20    is a block diagram of an embodiment of the in-ear speaker  1806  that is configured as an audio transparency system in accordance with one embodiment. As shown in  FIG.  20   , the in-ear speaker  1806  is inserted into the ear canal  104  and may form a seal against the wall of the ear canal  104 . The in-ear speaker  1806  can be designed as a sealable insertable in-ear speaker or a leaky insertable in-ear speaker, as defined herein. For one embodiment, the processor  1803  may be programmed in accordance with or include a transparency adjustment module  2003  and an ear canal identification module  2004 . The transparency adjustment module  2003  may be a variable, spectral shaping filter or equalizer. The ear canal identification module  2004  may serve to determine an equalization profile, based on which it may configure the digital filter coefficients of the spectral shaping filter in the transparency adjustment module  2003 . The valve  210  can be opened and closed as described above in connection with at least one of  FIGS.  1 - 17   , under control of a program that may be executed by the processor  1803 , e.g., during audio playback or during a phone call, that controls at a higher level the audio transparency of the in-ear speaker. Ambient environment sound is picked up by the microphone  1802 , which converts the sound into an electrical audio signal that is provided to the processor  1803  for further processing. 
     For one embodiment, the processor  1803  adjusts the spectrum of the electrical audio signal from the microphone  1802 , to compensate for any insertion losses that are due to the in-speaker  1806  being installed in the wearer&#39;s ear and therefore at least partially blocking the ear canal and that affect the ambient sound that leaks past the in-ear speaker housing and may be perceived the wearer. For one embodiment, the adjustment is based on an equalization profile of the ear canal. For one embodiment, the profile is a collection of one or more acoustic characteristics associated with the specific ear canal  104  of the wearer. Acoustic characteristics include, but are not limited to, a sound pressure associated with the ear canal; a particle velocity associated with the ear canal; a particle displacement associated with the ear canal; an acoustic intensity associated with the ear canal; an acoustic power associated with the ear canal; a sound energy associated with the ear canal; a sound energy density associated with the ear canal; a sound exposure associated with the ear canal; an acoustic impedance associated with the ear canal; an audio frequency associated with the ear canal; and a transmission loss associated with the ear canal. 
     Referring back to  FIG.  19   , the chart  1900  shows an example of how the processor  1803  can adjust  1903  the sounds  214  from the ambient environment that are picked up by the external microphone  1802  in order to provide those sounds with one or more characteristics that assist with enabling a user of the in-ear speaker  1806  to perceive the sounds  214  as if there was no in-ear speaker  1806  sealing the ear  102 . As shown in  FIG.  19   , the curve  1901  represents the sound pressure losses in decibels (dB) associated with sealing the ear canal (hereinafter “insertion losses”). As a specific example, the curve  1901  can be used to represent the insertion losses due to either a sealable or a leaky insertable in-ear speaker  1806 , when those sound pressure losses are measured at (or estimated for) the ear drum of a user of the in-ear speaker  1806 . The curve  1902  represents the sound pressure in an unsealed ear canal that enables a user of the in-ear speaker  1806  to perceive the sounds  214  comfortably. For one embodiment, the processor  1803  implements an equalizer or spectral shaping filter (transparency adjustment module  2003 ) that adjusts  1903  the frequency components of the sound  214  that is picked up by the microphone  1802 . As shown in  FIG.  19   , the equalizer of the processor  1803  adjusts (here, boosts)  1903  the gain at certain frequency components of the sound  214 , to compensate for the insertion losses, so as to give the sounds  214  a zero decibel (dB) insertion loss. 
     The adjustments  1903  that are intended to bring the curve  1901  closer to the curve  1902  may be realized by the spectral shaping filter that is part of the transparency adjustment module  2003 . The spectral shaping filter (e.g., its digital filter coefficients) may be defined based on the equalization (EQ) profile of the ear canal  104 . For one embodiment, the EQ profile is unique to a specific ear canal  104  of the wearer and no other ear canal  104 —i.e., each user or wearer has a unique EQ profile, because each user&#39;s actual ear canal is unique. The goal of the EQ profile is to define the recovery of any insertion losses attributable to the presence of the in-ear speaker (e.g., insertion losses due to the in-ear speaker  1806  when sound pressure losses are measured or estimated at the ear drum of a user of the in-ear speaker  1806 ) to a unity match, which is illustrated in  FIG.  19    in the form of the curve  1902  as a flat target. Curve  1902 , however, is not so limited. For example, the curve  1902  can be measured as a response to an external sound, at the ear drum of a user of the in-ear speaker  1806 , when that user&#39;s ear canal is not sealed by the in-ear speaker  1806 . For this example, the curve  1902  is not flat but includes resonances and other variations due to the ear canal geometry. Various forms of representing the curve  1902  to indicate the sound pressure within an unsealed ear canal are known in the art so they are not discussed in detail. 
     When the EQ profile is to be unique to each user, the EQ profile can be ascertained using one or more audio test signals that generated by the processor  1803  and used to measure the one or more acoustic properties of the ear canal  104 . The test signal is converted into sound, e.g., by an acoustic driver or transducer  2001  of the in-ear speaker  1806 , or by another acoustic driver (not shown), that can be picked up by the error microphone  2002  or by the external microphone  1802 . The ear canal identification module  2004  can the compute the EQ profile based on those microphone signals and based on other data received from outside of the in-ear speaker, e.g., from the external audio source device, and then on that basis computes the digital filter coefficients of the spectral shaping filter in the transparency adjustment module  2003 . 
     In another embodiment, the equalization profile is not unique to the ear canal  104  of the wearer. For this embodiment, the equalization profile is based on an average of multiple acoustic properties associated with multiple ear canals (e.g., a statistical measure across a number of wearers). In this way, the processor  1803  and in particular the transparency adjustment module  2003  (equalizer filter or spectral shaping filter) can be pre-programmed in accordance with the equalization profile of an “average” ear canal  104 ; in that case, the ear canal identification module  2004  may not be needed to compute the equalization profile, but may simply retrieve or receive the EQ profile, e.g., from the external source device. For this embodiment, the processor  1803  might not even have to actually compute the digital filter coefficients of the spectral shaping filter, as those could be retrieved from the external source device, which can assist with reducing costs associated with the processing operations performed by the processor  1803 . 
     For one embodiment, the processor  1803  (and in particular the transparency adjustment module  2003 ) adjusts the frequencies of the ambient sounds detected in the curve  1902  (described above in connection with  FIG.  19    that is determined) based on the equalization profile. Specifically, the processor  1803  adjusts the frequencies of the ambient sounds until those sounds exhibits zero decibel insertion losses, as shown in the curve  1902  described above in connection with  FIG.  19   . 
     For one embodiment, the adjusted audio signal is converted into sound (after being amplified by a power amplifier, PA) and delivered by the output transducer  2001 , to the ear canal  104 . The output transducer  2001  can be any kind of transducer capable of converting electrical audio signals into acoustic signals that can be perceived by a user&#39;s ear drum. For one embodiment, the output transducer  2001  is also an acoustic driver of the in-ear speaker  1806  that receives as input a user content audio signal produced by an external electronic audio source device (e.g., a smartphone, a portable media player), for delivering user content sounds to the ear canal  104 . The in-ear speaker may have a communications interface  2005  (e.g., a wire or cable interface, or a wireless interface such as a Bluetooth transceiver) through with the user content audio signal is received. The processor  1803  may include an audio mixer that combines the user content audio signal with the processed (adjusted) ambient content audio signal (from the transparency adjustment module  2003 ) into a single signal, before the conversion into sound by the transducer  2001 . 
       FIG.  21    is a flow diagram of a process for sound augmentation in an in-ear speaker as a hybrid transparency system in accordance with one embodiment. The process can be performed by the electronic and transducer components of an insertable in-ear speaker, such as the in-ear speakers described above in connection with  FIGS.  18 - 20   . The process may begin when one or more sounds from the ambient environment are being picked up and converted into one or more electrical audio signals, by an external microphone of the in-ear speaker (operation  2104 ). In operation  2106 , the electrical audio signals are processed to adjust one or more frequency components of sounds, to compensate for the insertion loss. For one embodiment, operation  2106  is performed in accordance with the description provided above in connection with at least one of  FIGS.  18 - 20   . When a decision has been made (e.g., by the processor  1803 ) that audio transparency is needed, the process continues with operation  2108  in which the ambient content audio signal as it has been adjusted to compensate for insertion loss, is converted into sound that is delivered to the wearer&#39;s ear canal, and operation  2107  in which the valve  210  (see  FIG.  20   ) is signaled by the processor  1803  to open. The sound augmentation path (from the microphone  1802  to the transducer  2001 ) may be particularly effective in improving the wearer&#39;s ability to hear the ambient content that is above 1 kHz, and more particularly above 1500 Hz, while the valve  210 , which is simultaneously open, improves the wearer&#39;s ability to hear the ambient content that is below 1 kHz, and more particularly below 1500 Hz. 
       FIGS.  22 A-B  are charts illustrating at least one benefit of an in-ear speaker that includes the valve  210  and the sound augmentation system in accordance with one embodiment. Referring to  FIG.  22 A , the chart  2300  illustrates a curve  2301 , a curve  2302 , and a region  2303  created by an overlap of the curves  2301  and  2302 . The curve  2301  represents unwanted energy in an occluded ear canal that is produced due to footfalls (e.g., running, walking, etc.) The curve  2302  represents energy in an open ear canal that is produced due to footfalls (e.g., running, walking, etc.). The energy represented by the curve  2302  is at a level that is comfortable for a user&#39;s perception of audio inside his ear canal. The energy in region  2303  represents the energy that should be mitigated or removed from an occluded ear that is sealed by any of in-ear speakers described above in connection with  FIGS.  5 A- 21   . For one embodiment, an in-ear speaker that includes the valve  210  and the sound augmentation system described above in connection with  FIGS.  5 A- 21    can assist with mitigating the energy represented by the curve  2301  to be closer to the energy represented by the curve  2302 , by reducing the unwanted energy represented by the region  2303 . 
     Referring now to  FIG.  22 B , a chart  2399  illustrates how an in-ear speaker that includes the valve  210  and the sound augmentation system (e.g., any one of the in-ear speakers described above in connection with  FIGS.  18 - 21   ) contributes to reducing an occlusion effect and to improving audio transparency experienced by a user of such an in-ear speaker. The chart  2399  includes a curve  2350 , a curve  2351 , and a curve  2352 . The curve  2350  represents energy within an open ear that is not occluded or sealed. The curve  2351  represents energy within a sealed ear when the valve  210  (e.g., any one of the BA based valves described above in connection with  FIGS.  5 A- 21   ) is functioning and is open but while the sound augmentation is inactive. The ear is sealed with an in-ear speaker that includes the valve  210  and a sound augmentation system (e.g., any one of the in-ear speakers described above in connection with  FIGS.  18 - 21   ). The curve  2352  represents energy within the sealed ear when the sound augmentation system is active and the valve is closed. As can be recognized from  FIG.  22 B , the valve  210  by itself can assist with mitigating unwanted energy from a sealed ear, at frequencies that are approximately below 1500 Hz but not at frequencies above 1500 Hz. At frequencies above 1500 Hz, the sound augmentation system can assist with increasing the desired energy in the sealed ear, while the valve  210  is open. In this way, the in-ear speaker is a hybrid transparency system that includes both the valve  210  and the sound augmentation system working simultaneously to assist with reducing occlusion effects and improving audio transparency. 
     Each of  FIGS.  22 A-B  are illustrative charts used to show at least one benefit of an in-ear speaker that includes an acoustic pass valve and a sound augmentation system. It is to be appreciated that the values in the charts are approximate or ideal values (not exact or real values). 
     Returning to the flow diagram of  FIG.  21   , the process may continue with the processor  1803  deciding at some point that audio transparency is not needed. In that case, the process continues with operation  2110  in which conversion of the ambient audio signal into sound is halted, by the processor  1803  (the sound augmentation system is deactivated), and simultaneously the valve  210  is signaled to close (operation  2109 ). This returns the in-ear speaker to its state in which it aims to prevent the ambient sounds from being heard by the wearer of the in-ear speaker. 
       FIG.  23    is a block diagram illustrating an example of a data processing system  2200  that may be used with one embodiment. For a first example, system  2200  may represent any of data processing systems described above performing any of the processes or methods described above. For a second example, system  2200  may represent any of data processing systems used to generate music that is provided to any one of the embodiments of an in-ear speaker as described above in connection with at least one of  FIGS.  1 - 21   . For a third example, system  2200  may represent any of in-ear speakers used to deliver music to an ear canal as described above in connection with at least one of  FIGS.  1 - 21   . 
     System  2200  can include many different components. These components can be implemented as integrated circuits (ICs), portions thereof, discrete electronic devices, or other modules adapted to a circuit board such as a motherboard or add-in card of the computer system, or as components otherwise incorporated within a chassis of the computer system. Note also that system  2200  is intended to show a high-level view of many components of the computer system. Nevertheless, it is to be understood that additional components may be present in certain implementations and furthermore, different arrangement of the components shown may occur in other implementations. System  2200  may represent a desktop, a laptop, a tablet, a server, a mobile phone, a media player, a personal digital assistant (PDA), a personal communicator, a gaming device, a network router or hub, a wireless access point (AP) or repeater, a set-top box, an in-ear speaker, or a combination thereof. Further, while only a single machine or system is illustrated, the term “machine” or “system” shall also be taken to include any collection of machines or systems that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. 
     In one embodiment, system  2200  includes processor  2201 , memory  2203 , and devices  2205 - 1508  via a bus or an interconnect  2210 . Processor  2201  can be programmed to execute instructions for performing any of the digital processing operations described above. System  2200  may further include a graphics interface that communicates with optional graphics subsystem  2204 , which may include a display controller, a graphics processor, and/or a display device. Processor  2201  may communicate with memory  2203 , which in one embodiment can be implemented via multiple memory devices to provide for a given amount of system memory. System  2200  may further include IO devices such as devices  2205 - 1508 , including network interface device(s)  2205 , optional input device(s)  2206 , and other optional IO device(s)  2207 . Network interface device  2205  may include a wireless transceiver and/or a network interface card (NIC). The wireless transceiver may be a WiFi transceiver, an infrared transceiver, or a Bluetooth transceiver (e.g. used to communicate with the in-ear speaker.) Input device(s)  2206  may include a mouse, a touch pad, a touch sensitive screen (which may be integrated with display device  2204 ), a pointer device such as a stylus, and/or a keyboard (e.g., physical keyboard or a virtual keyboard displayed as part of a touch sensitive screen). IO devices  2207  may include an audio device. An audio device may include a speaker and/or a microphone to facilitate voice-enabled functions, such as voice recognition, digital recording, telephony functions and for producing test sounds. Other IO devices  2207  may include universal serial bus (USB) port(s), sensor(s) (e.g., a motion sensor such as an accelerometer, gyroscope, a magnetometer, a light sensor, compass, a proximity sensor, etc.), or a combination thereof. Devices  2207  may further include an imaging processing subsystem (e.g., a camera), which may include an optical sensor, such as a charged coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) optical sensor, utilized to facilitate camera functions. Certain sensors may be coupled to interconnect  2210  via a sensor hub (not shown), while other devices such as a keyboard or thermal sensor may be controlled by an embedded controller (not shown), dependent upon the specific configuration or design of system  2200 . 
     Note that while system  2200  is illustrated with various components of a data processing system, it is not intended to represent any particular architecture or manner of interconnecting the components; such details may not be germane to embodiments of the present invention. It will also be appreciated that network computers, handheld computers, mobile phones, servers, and/or other data processing systems, which have fewer components or perhaps more components, may also be used with embodiments of the invention. 
     Some portions of the preceding detailed descriptions have been presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the ways used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. 
     It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as those set forth in the claims below, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     Embodiments of the invention also relate to an apparatus for performing the operations herein. Such a computer program is stored in a non-transitory computer readable medium. A machine-readable medium includes any mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a machine-readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium (e.g., read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices). 
     The processes or methods depicted in the preceding figures may be performed by logic or logic circuitry (also referred to as processing logic) that comprises hardware (e.g. circuitry, dedicated logic, etc.), software (e.g., stored or embodied on a non-transitory computer readable medium), or a combination of both. Although the processes or methods are described above in terms of some sequential operations, it should be appreciated that some of the operations described may be performed in a different order. Moreover, some operations may be performed in parallel rather than sequentially. 
     In the foregoing specification, embodiments of the invention have been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the invention as set forth in the following claims. Also, it is to be appreciated that each of the devices, components, or objects illustrated in  FIGS.  1 - 23    are not necessarily drawn to scale and that the sizes of these components are not necessarily identical. For example, the coil assembly  414  illustrated in  FIG.  8    may or may not be identical in size and/or shape to the coil assembly  514  illustrated in  FIG.  8   . 
     The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.