PATENT DOCUMENT

Publication Number: US-11882394-B2
Application Number: US-202217670347-A
Country: US
Kind Code: B2

Title: Vented liquid-resistant microphone assembly

Abstract:
Aspects of the subject technology relate to liquid-resistant microphone modules for electronic devices. A microphone module may include a non-porous membrane that seals the front volume of the microphone module from the external environment of the electronic device. The microphone module may also include a substrate having an opening that allows airflow between the front volume and an interior cavity within the housing of the electronic device. In various implementations, an inductive vent and/or a resistive vent may be provided over the opening in the substrate.

Claims:
What is claimed is: 
     
       1. A microphone module, comprising:
 a substrate having a first side and an opposing second side; 
 a cover mounted to the first side of the substrate and at least partially defining a back volume of the microphone module; 
 a front volume that is separated from the back volume by a sound-responsive element and that is fluidly coupled to a first opening in the substrate; 
 a non-porous membrane that defines a sealed volume fluidly coupled to the front volume via the first opening, and that provides a liquid-resistant seal between the front volume and a first environment external to the microphone module on an opposing second side of the substrate; and 
 a second opening in the substrate that extends from the sealed volume defined by the non-porous membrane, through the substrate, to a second environment external to the microphone module on the first side of the substrate. 
 
     
     
       2. The microphone module of  claim 1 , further comprising a resistive vent over the second opening on the first side of the substrate. 
     
     
       3. The microphone module of  claim 1 , further comprising a resistive vent over the second opening on the opposing second side of the substrate. 
     
     
       4. The microphone module of  claim 1 , further comprising an inductive vent over the second opening on the first side of the substrate. 
     
     
       5. The microphone module of  claim 1 , further comprising an inductive vent over the second opening on the opposing second side of the substrate, wherein the non-porous membrane is mounted to the opposing second side of the substrate. 
     
     
       6. The microphone module of  claim 1 , further comprising an inductive vent over the second opening on the opposing second side of the substrate, wherein the non-porous membrane is mounted to the inductive vent. 
     
     
       7. The microphone module of  claim 6 , further comprising a circuitry block on the first side of the substrate. 
     
     
       8. The microphone module of  claim 7 , further comprising a resistive vent mounted over the second opening on the first side of the substrate. 
     
     
       9. The microphone module of  claim 8 , wherein the resistive vent is disposed in the circuitry block. 
     
     
       10. The microphone module of  claim 1 , further comprising:
 a circuitry block on the first side of the substrate; and 
 a resistive vent disposed in the circuitry block. 
 
     
     
       11. The microphone module of  claim 10 , further comprising an additional circuitry block mounted on the first side of the substrate. 
     
     
       12. The microphone module of  claim 1 , further comprising:
 a resistive vent over the second opening on the first side of the substrate; and 
 an inductive vent over the second opening on the opposing second side of the substrate. 
 
     
     
       13. The microphone module of  claim 1 , further comprising:
 an inductive vent over the second opening on the first side of the substrate; and 
 a resistive vent over the second opening on the opposing second side of the substrate. 
 
     
     
       14. The microphone module of  claim 1 , further comprising:
 a circuitry block including a resistive vent mounted over the second opening on the first side of the substrate; and 
 an inductive vent over the second opening on the opposing second side of the substrate. 
 
     
     
       15. The microphone module of  claim 1 , further comprising:
 an inductive vent mounted over the second opening on the first side of the substrate; and 
 a resistive vent mounted on the inductive vent. 
 
     
     
       16. The microphone module of  claim 1 , further comprising:
 a circuitry block mounted over the second opening on the first side of the substrate; 
 a resistive vent spanning an opening on the circuitry block; and 
 an inductive vent mounted over the second opening on the first side of the substrate and within the opening in the circuitry block. 
 
     
     
       17. The microphone module of  claim 1 , further comprising:
 an inductive vent mounted over the second opening on the opposing second side of the substrate; 
 a third opening in the substrate; and 
 an opening in the inductive vent, the opening in the inductive vent aligned with the third opening in the substrate to fluidly couple the front volume and the back volume. 
 
     
     
       18. The microphone module of  claim 17 , further comprising a resistive vent over the second opening on the first side of the substrate. 
     
     
       19. The microphone module of  claim 18 , wherein the resistive vent is disposed within a circuitry block attached to the first side of the substrate. 
     
     
       20. The microphone module of  claim 1 , further comprising an inductive filter disposed in the substrate and extending from the first opening to the second opening. 
     
     
       21. The microphone module of  claim 20 , wherein the non-porous membrane is mounted to the opposing second side of the substrate or to a cover for the inductive filter. 
     
     
       22. The microphone module of  claim 21 , further comprising a third opening in the substrate fluidly coupling the front volume and the back volume. 
     
     
       23. The microphone module of  claim 20 , further comprising a resistive vent over the second opening on the first side of the substrate. 
     
     
       24. The microphone module of  claim 23 , wherein the non-porous membrane is mounted to the opposing second side of the substrate or to a cover for the inductive filter. 
     
     
       25. The microphone module of  claim 24 , further comprising a third opening in the substrate fluidly coupling the front volume and the back volume. 
     
     
       26. The microphone module of  claim 23 , wherein the resistive vent is disposed in a circuitry block mounted to the first side of the substrate. 
     
     
       27. The microphone module of  claim 26 , wherein the non-porous membrane is mounted to the opposing second side of the substrate or to a cover for the inductive filter. 
     
     
       28. The microphone module of  claim 27 , further comprising a third opening in the substrate fluidly coupling the front volume and the back volume. 
     
     
       29. An electronic device, comprising:
 a housing defining an internal volume; 
 a microphone module disposed within the internal volume, the microphone module comprising:
 a substrate; 
 a cover mounted to the substrate, wherein the cover separates a back volume of the microphone module from the internal volume, 
 a front volume that is separated from the back volume by a sound-responsive element and that is fluidly coupled to a first opening in the substrate; 
 a non-porous membrane that defines a sealed volume that is fluidly coupled to the front volume via the first opening, and that provides a liquid-resistant seal between the front volume and an environment external to the housing; and 
 a second opening in the substrate that extends from the sealed volume defined by the non-porous membrane, through the substrate, to the internal volume of the housing external to the cover. 
 
 
     
     
       30. The electronic device of  claim 29 , further comprising at least one of a resistive filter or an inductive filter mounted over the second opening in the substrate. 
     
     
       31. A method of operating a liquid-resistant microphone of an electronic device, the method comprising:
 receiving sound from an environment external to the electronic device at a sound-responsive element of the liquid-resistant microphone through a non-porous membrane of the liquid-resistant microphone and through first opening in a substrate of the liquid-resistant microphone; and 
 generating an electronic signal based on a motion of the sound-responsive element due to the received sound, 
 wherein the motion of the sound-responsive element due to the received sound causes airflow through a second opening in the substrate between a front volume of the liquid-resistant microphone that is at least partially defined by the non-porous membrane and an interior cavity of the electronic device that is separated from a back volume of the liquid-resistant microphone by a cover mounted to the substrate. 
 
     
     
       32. The method of  claim 31 , wherein the airflow passes through at least one of a resistive filter or an inductive filter mounted over the second opening in the substrate.

Description:
TECHNICAL FIELD 
     The present description relates generally to acoustic devices including vented liquid-resistant microphone assemblies. 
     BACKGROUND 
     Electronic devices such as computers, media players, cellular telephones, and other electronic equipment are often provided with acoustic components such as microphones. It can be challenging to integrate acoustic components into electronic devices, such as in compact devices including portable electronic devices. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain features of the subject technology are set forth in the appended claims. However, for purpose of explanation, several aspects of the subject technology are set forth in the following figures. 
         FIG.  1    illustrates a perspective view of an example electronic device having a microphone in accordance with various aspects of the subject technology. 
         FIG.  2    illustrates a cross-sectional view of a portion of an electronic device including a vented liquid-resistant microphone adjacent to an opening in a housing of the device in accordance with various aspects of the subject technology. 
         FIG.  3    illustrates a cross-sectional side view of a vented liquid-resistant microphone module in accordance with various aspects of the subject technology. 
         FIG.  4    illustrates a cross-sectional side view of a vented liquid-resistant microphone module having a resistive vent in accordance with various aspects of the subject technology. 
         FIG.  5    illustrates a cross-sectional side view of a portion of another vented liquid-resistant microphone module having a resistive vent in accordance with various aspects of the subject technology. 
         FIG.  6    illustrates a cross-sectional side view of a vented liquid-resistant microphone module having an inductive vent in accordance with various aspects of the subject technology. 
         FIG.  7    illustrates a cross-sectional side view of a portion of another vented liquid-resistant microphone module having an inductive vent in accordance with various aspects of the subject technology. 
         FIG.  8    illustrates a cross-sectional side view of another vented liquid-resistant microphone module having an inductive vent in accordance with various aspects of the subject technology. 
         FIG.  9    illustrates a cross-sectional side view of a portion of a vented liquid-resistant microphone module having a resistive vent and an inductive vent in accordance with various aspects of the subject technology. 
         FIG.  10    illustrates a cross-sectional side view of a vented liquid-resistant microphone module having a resistive vent disposed in a circuit block in accordance with various aspects of the subject technology. 
         FIG.  11    illustrates a cross-sectional side view of a portion of another vented liquid-resistant microphone module having a resistive vent and an inductive vent in accordance with various aspects of the subject technology. 
         FIG.  12    illustrates a cross-sectional side view of a portion of another vented liquid-resistant microphone module having a resistive vent and an inductive vent in accordance with various aspects of the subject technology. 
         FIG.  13    illustrates a cross-sectional side view of a portion of another vented liquid-resistant microphone module having a resistive vent and an inductive vent in accordance with various aspects of the subject technology. 
         FIG.  14    illustrates a cross-sectional side view of a portion of a vented liquid-resistant microphone module having an inductive vent and a resistive vent disposed in a circuit block in accordance with various aspects of the subject technology. 
         FIG.  15    illustrates a cross-sectional side view of a portion of a vented liquid-resistant microphone module having an inductive vent and an additional vent to a back volume in accordance with various aspects of the subject technology. 
         FIG.  16    illustrates a cross-sectional side view of a portion of a vented liquid-resistant microphone module having an inductive vent that is at least partially disposed in a microphone substrate in accordance with various aspects of the subject technology. 
         FIG.  17    illustrates a cross-sectional side view of a resistive vent in accordance with various aspects of the subject technology. 
         FIG.  18    illustrates aspects of a circuit block that includes a resistive vent in accordance with various aspects of the subject technology. 
         FIG.  19    illustrates a simplified cross-sectional side view of an inductive vent having a first port on a first side and a second port on an opposing second side in accordance with various aspects of the subject technology. 
         FIG.  20    illustrates a simplified cross-sectional side view of an inductive vent having a first port and a second port on a first side in accordance with various aspects of the subject technology. 
         FIG.  21    illustrates a simplified cross-sectional side view of an inductive vent having a first port on an edge and a second port on a side in accordance with various aspects of the subject technology. 
         FIG.  22    illustrates a cross-sectional top view of an inductive vent having first and second ports on one or more sides and a serpentine fluid pathway therebetween in accordance with various aspects of the subject technology. 
         FIG.  23    illustrates a cross-sectional top side view of an inductive vent having a first port on an edge, a second port on a side, and a serpentine fluid pathway therebetween in accordance with various aspects of the subject technology. 
         FIG.  24    illustrates a side view of an inductive vent having a first port on an edge and a second port on a side, and a serpentine fluid pathway therebetween in accordance with various aspects of the subject technology. 
         FIG.  25    illustrates a cross-sectional side view of an inductive vent in accordance with various aspects of the subject technology. 
         FIG.  26    illustrates a top perspective view of a fluid pathway of an inductive vent in accordance with various aspects of the subject technology. 
         FIG.  27    illustrates a cross-sectional side view of a microphone substrate including an embedded inductive vent in accordance with various aspects of the subject technology. 
         FIG.  28    illustrates aspects of metal layers of a microphone substrate including an embedded inductive vent in accordance with various aspects of the subject technology. 
         FIG.  29    illustrates a flowchart of illustrative operations that may be performed for operating a vented liquid-resistant microphone in accordance with various aspects of the subject technology. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. 
     Electronic devices such as desktop computers, televisions, set top boxes, internet-of-things (IoT) devices, and portable electronic devices including mobile phones, portable music players, smart watches, tablet computers, smart speakers, remote controllers for other electronic devices, headphones, earbuds, and laptop computers often include one or more sensors that respond to air movement and/or acoustic signals such as sound (e.g., from outside a housing of the device) to transduce a signal, and/or one or more components such as speakers that move air based on received signals. The sensors can include, as examples, acoustic sensors, which may include microphones for sound input to the device, pressure sensors, and/or ultrasonic sensors. 
     For example, a sensor such as a pressure sensor or an acoustic sensor, or any combination thereof, may be disposed within the housing of an electronic device and configured to receive input from outside the housing, in part due to airflow from outside the housing into the housing at various openings or ports. However, it can also be desirable to prevent liquid ingress into the housing of the electronic device and/or into a sensor module, such as a microphone module, an ultrasonic sensor module, a pressure sensor module, or any combination thereof. In some sensor modules, a porous membrane that allows airflow therethrough can be included to provide liquid resistance for the sensor module. To achieve low acoustic loss across a porous membrane, the porous membrane may be thin and compliant, which may generally cause the porous membrane to be less robust for high ingress pressures due to deep liquid (e.g., water) immersion, such as immersion at a depth of greater than about six meters. 
     In accordance with various aspects of the subject disclosure, a sensor module such as a microphone module or an ultrasonic sensor module may be provided with a non-porous membrane that extends over an acoustic port and prevents liquid ingress into the sensor module. For example, a non-porous membrane may be placed such that it forms a boundary between a front volume of a microphone module and an external environment of the microphone module, and prevents liquid and air ingress into the microphone module. To achieve low acoustic loss across a non-porous membrane, the non-porous membrane may be thin and relatively stiff, which may help provide more a robust membrane structure than a porous membrane, and which may be resistant to large liquid ingress pressures due to deep liquid (e.g., water) immersion to depths up to, for example, one hundred meters. However, while a (e.g., thin and relatively stiff) non-porous membrane may allow sound to pass through the membrane from the external environment to a sound-responsive element of the microphone module, the non-porous membrane may restrict or prevent airflow between the front volume and the external environment, which can be detrimental to the functioning of an acoustic component such as a microphone or an ultrasonic sensor. 
     In order, for example, to obtain the liquid-resistant benefits of a microphone module with a non-porous membrane over the acoustic port, while maintaining functionality of the microphone, the microphone module may be provided with a leak port to allow airflow into and out of the front volume that is sealed from the external environment by the non-porous membrane. 
     In one or more implementations, an opening may be provided in a substrate of a sensor module, such as a microphone module having a non-porous membrane. The opening may extend from a sealed volume that is on a first side of the substrate and that is fluidly coupled to the front volume and that is sealed by the non-porous membrane, to another environment external to the microphone module, such as an external environment on an opposing second side of the substrate. In one or more implementations, the sensor module having the non-porous membrane and the leak port may be implemented in an electronic device, such as a smart phone, a smart watch, a tablet device, or the like, having a housing that defines an interior volume in which the microphone module is disposed. In one or more implementations, the leak port through the substrate of the microphone module may fluidly couple the sealed volume on the first side of the substrate that is fluidly coupled to the front volume and that is sealed by the non-porous membrane, to the interior volume of the electronic device. In this way, the interior volume of the electronic device can act as an air reservoir for venting from the front volume of the microphone module. In one or more implementations, a resistive vent or resistive filter, and/or an inductive vent or inductive filter may be provided over the leak port to prevent sound from within the internal cavity from reaching a sound-responsive element of a microphone. 
     An illustrative electronic device including a sensor module such as a microphone module is shown in  FIG.  1   . In the example of  FIG.  1   , electronic device  100  has been implemented using a housing  106  that is sufficiently small to be portable and carried or worn by a user (e.g., electronic device  100  of  FIG.  1    may be a handheld electronic device such as a tablet computer or a cellular telephone or smart phone, or a wearable device such as a smart watch, a headphone, or an earbud). In the example of  FIG.  1   , electronic device  100  includes a display such as display  110  mounted on the front of housing  106 . Electronic device  100  includes one or more input/output devices such as a touch screen incorporated into display  110 , a virtual or mechanical button or switch, and/or other input output components disposed on or behind display  110  or on or behind other portions of housing  106 . Display  110  and/or housing  106  may form an enclosure within which components (e.g., one or more processors, volatile or non-volatile memory, a battery, one or more integrated circuits, one or more speakers, or other components) of the electronic device  100  are disposed. Display  110  and/or housing  106  may include one or more openings to accommodate a button, a switch, a speaker, a light source, a sensor such as a microphone, and/or a camera (as examples). 
     In the example of  FIG.  1   , housing  106  includes an opening  108  in the housing  106 . In this example, opening  108  forms a port for a sensor, such as a microphone, that receives acoustic input, such as sound from the external environment outside of the housing  106 . For example, opening  108  may form a sensor port for a sensor module disposed within housing  106 , such as a microphone port for a microphone module disposed within housing  106 , and/or an ultrasonic sensor port for an ultrasonic sensor disposed within housing  106 . One or more additional openings in housing  106  and/or the display  110 , though not explicitly shown in  FIG.  1   , may form a speaker port for a speaker disposed within the housing  106 . 
     Opening  108  may be an open port or may be completely or partially covered with an air-permeable membrane and/or a mesh structure that allows air and sound to pass through the openings. Although one opening  108  is shown in  FIG.  1   , this is merely illustrative. One opening  108 , two openings  108 , or more than two openings  108  may be provided on the top edge and/or the bottom edge of housing  106 , and/or one or more openings may be formed on sidewall (e.g., a left or right sidewall). Although opening  108  is depicted, in  FIG.  1   , on an edge of the housing  106 , one or more additional openings for acoustic components and/or sensors may be formed on a rear surface of housing  106  and/or a front surface of housing  106  or display  110 . In some implementations, one or more groups of openings  108  in housing  106  may be aligned with an acoustic port of an acoustic component and/or a sensor within housing  106 . 
     Housing  106 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. In one example, housing  106  may be formed from a metal peripheral portion that runs (e.g., continuously or in pieces) around the periphery of electronic device  100  to form a top edge, a bottom edge, and sidewalls running therebetween, and/or a metal or glass rear panel mounted to the metal peripheral portion. In this example, an enclosure may be formed by the metal peripheral portion, the rear panel, and display  110 , and device circuitry such as a battery, one or more processors, memory, application specific integrated circuits, sensors, antennas, acoustic components, and the like are housed within this enclosure. 
     However, it should be appreciated that the configuration of electronic device  100  of  FIG.  1    is merely illustrative. In other implementations, electronic device  100  may be a computer such as a smart watch, a pendant device, or other wearable or miniature device, a media player, a gaming device, a navigation device, a computer monitor, a television, a headphone, or a somewhat larger device such as a computer that is integrated into a display such as a computer monitor, a laptop computer, or other electronic equipment. 
     For example, in some implementations, housing  106  may be formed using a unibody configuration in which some or all of housing  106  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). Although housing  106  of  FIG.  1    is shown as a single structure, housing  106  may have multiple parts. For example, in other implementations, housing  106  may have upper portion and lower portion coupled to the upper portion using a hinge that allows the upper portion to rotate about a rotational axis relative to the lower portion. A keyboard such as a QWERTY keyboard and a touch pad may be mounted in the lower housing portion, in some implementations. 
     In some implementations, electronic device  100  may be provided in the form of a wearable device such as a smart watch. For example, in some implementations, housing  106  may include one or more interfaces for mechanically coupling housing  106  to a strap or other structure for securing housing  106  to a wearer. In some implementations, electronic device  100  may be a mechanical or other non-electronic device in which a microphone can be mounted within the housing, such as a pen or a support structure such as a monitor stand for a computer monitor. In any of these exemplary implementations, housing  106  includes an opening  108  associated with a microphone module. In some implementations, electronic device  100  may be provided in the form of a computer integrated into a computer monitor and/or other display, such as a television. Display  110  may be mounted on a front surface of housing  106  and optionally a stand may be provided to support the housing  106  (e.g., on a desktop) and/or housing  106  may be mounted on a surface, such as a wall. 
     A sensor module disposed within housing  106  receives sound through at least one associated opening  108 .  FIG.  2    shows a cross-sectional view of a portion of electronic device  100  in which a sensor module is mounted. For illustrative purposes, the sensor module is described herein in as being implemented as a microphone module  202 . However, it should be appreciated that the microphone module  202  can be operable as another type of sensor module, such as an ultrasonic sensor module by providing a sound-responsive element that is responsive to acoustic signals with a frequency greater than 20 kilohertz. 
     In the example of  FIG.  2   , electronic device  100  includes a sensor module implemented as a microphone module  202  mounted within housing  106 , adjacent to and aligned with an opening  108  in the housing  106 . In this example, microphone module  202  is mounted to an interior surface  221  of housing  106 , such as within an enclosure formed by the housing  106  and the display  110  of  FIG.  1   . 
     As shown, microphone module  202  may include a substrate  204  (e.g., a printed circuit board (PCB) substrate, such as a multi-layer PCB) attached to the interior surface  221 , such as by adhesive  212 . Adhesive  212  may be, for example, a sealing pressure sensitive adhesive (PSA), or another adhesive or attachment mechanism, that attaches substrate  204  to interior surface  221  such that the mounting interface is sealed against ingress of moisture or other contaminants into housing  106  via pathways between the substrate  204  and the interior surface  221 . In the example of  FIG.  2   , an opening  215  (e.g., a first opening) in the substrate  204  is aligned with the opening  108  in housing  106  to allow sound to pass from an environment  219  external to the housing  106  to a sensor assembly  218  mounted on the substrate  204 . In this way, sensor assembly  218  is in fluid and acoustic communication with the opening  215  in substrate  204  (and in acoustic communication with the opening  108  in the housing  106 ). Sensor assembly  218  may include, for example, a microelectromechanical systems (MEMS) microphone assembly having a moveable or flexible membrane that, when moved or flexed by incoming sound, causes the MEMS microphone to generate electrical signals corresponding to the incoming sound. As another example, the sensor assembly  218  may include a movable or flexible diaphragm attached to a voice coil in which a current is generated when the diaphragm moves and/or flexes. As discussed in further detail hereinafter, the sensor assembly  218  may include additional microphone circuitry coupled to the substrate  204 . 
     As shown in  FIG.  2   , the sensor assembly  218  of microphone module  202  is disposed under a cover  208  (sometimes referred to as a lid, a can or a shield can) mounted on substrate  204  over the sensor assembly  218 . In this configuration, a cavity formed between sensors assembly  218  and the cover  208  defines a back volume  210  of sensor assembly  218 . 
     As shown in  FIG.  2   , the microphone module  202  may include a non-porous membrane  216 . As shown, the non-porous membrane  216  may span across the opening  215  in the substrate and may fluidly separate a sealed volume within the microphone module from the environment  219  external to the housing  106  (e.g., on a first side of the substrate  204 ). For example, the non-porous membrane  216  may prevent air and fluid flow across the membrane, and still function as a low loss acoustic membrane. In the example of  FIG.  2   , the non-porous membrane  216  is mounted within a recess  214  in the substrate  204 . As discussed in further detail hereinafter, the non-porous membrane  216  may seal a front volume of the microphone module from the environment  219  external to the housing  106 . In this way, a liquid-resistant microphone module may be provided. 
     In order to, for example, provide venting for the liquid-resistant microphone module that has the non-porous membrane  216  sealing the front volume of the microphone from the environment  219 , an opening  209  (e.g., a second opening) may be provided in the substrate  204 . The opening  209  can provide a leak port from the front volume of the microphone module  202  to another environment external to the microphone module, such as an internal volume  222  of the electronic device  100 . As shown in  FIG.  2   , the internal volume  222  within the electronic device  100 , in which the microphone module  202  is implemented, may be separated from the back volume  210  by the cover  208 . In this way, the internal volume  222  may be sealed from the back volume  210  and may function as an air reservoir for the microphone module  202 . 
     In accordance with various implementations described herein, the microphone module  202  may also include various arrangements of resistive and/or inductive acoustic vents and/or filters over the opening  209  in the substrate  204 , to allow air to flow through the opening  209  while preventing sound from leaking (e.g., from the internal volume  222 ) through the opening  209  to the sensor assembly  218 . In one or more implementations, an additional leak path also can be provided through the substrate  204  from the front volume to the back volume  210 . 
     In one or more implementations described in further detail hereinafter, a resistive vent can be provided at opening  209  in the substrate  204 . In one or more implementations described in further detail hereinafter, an inductive vent can be provided at opening  209  in the substrate  204 . The inductive vent can include a first port coupled to the front volume of the microphone module  202 , a second port coupled to the opening  209  in the substrate  204 , and a fluid pathway, such as a serpentine fluid pathway from the first port to the second port. Various implementations and arrangements of inductive and resistive vents are also disclosed herein. 
       FIG.  3    shows a cross-sectional side view of the microphone module  202  in an exemplary implementation. In the example of  FIG.  3   , the microphone module  202  includes the substrate  204  having a side  311  (e.g., a first side) and a side  313  opposite the first side (e.g., an opposing second side). As shown, the cover  208  may be mounted to the side  311  of the substrate  204  and may at least partially define (e.g., along with a portion of the substrate  204  and a portion of the sensor circuitry) the back volume  210  of the microphone module  202 . For example, the cover  208  may be attached to the surface of the substrate  204  on the side  311  using a conductive adhesive  302 , such as a solder material. In one or more implementations, the solder material may also fluidly seal the back volume  210  from an environment outside the cover, such as the internal volume  222  of the electronic device  100 . In the cross-sectional side view of  FIG.  3   , it can be seen that a front volume  300  is separated from the back volume  210  by a sound-responsive element  316 . As shown, the front volume  300  is fluidly coupled to the opening  215  in the substrate  204 . 
     In the example of  FIG.  3   , the non-porous membrane  216  is attached to the side  313  of the substrate within the recess  214  in the substrate, and substantially spans the recess  214 . In various implementations, the non-porous membrane  216  may be formed from a polytetrafluoroethylene (PTFE) film, such as a non-expanded PTFE film, or a polyimide film. The non-porous membrane may have a thickness of, for example, between one micron and twenty microns, in various implementations. 
     As shown in  FIG.  3   , the non-porous membrane  216  defines a sealed volume  301  that is fluidly coupled to the front volume  300  via the opening  215 . In this configuration, the non-porous membrane  216  provides a liquid-resistant seal between the front volume  300  and a first environment external to the microphone module  202  on the side  313  of the substrate  204  (e.g., the environment  219  external to the electronic device  100  in one or more implementations). As shown, the opening  209  in the substrate  204  may extend from the sealed volume  301  defined by the non-porous membrane  216 , through the substrate  204 , to a second environment external to the microphone module on the side  311  of the substrate  204  (e.g., a second environment formed by or including the internal volume  222  of the electronic device  100  in one or more implementations). In this way, the opening  209  allows airflow  333  (e.g., due to motion of a sound-responsive element  316 ), through the opening  209 , between the sealed volume  301  and the environment external to the microphone module on the side  311  of the substrate  204 . 
     In the example of  FIG.  3   , the microphone module  202  includes a sound-responsive element  316 . The sound responsive element may be a moveable diaphragm or an actuatable MEMS structure, in various implementations. The sound-responsive element  316  may move and/or vibrate responsive to sound that passes through the non-porous membrane  216 . Motion of the sound-responsive element  316  may induce an electrical response that is passed to microphone circuitry, such as an integrated circuit  318  (e.g., an application-specific integrated circuit) that is also disposed under the cover  208  and within the back volume  210 , for processing microphone signals generated by the sound-responsive element  316 . For example, the sound-responsive element  316  and the integrated circuit  318  may form all or part of the sensor assembly  218  of  FIG.  2   . Microphone signals generated by the sound-responsive element  316  and/or processed by the integrated circuit  318  may be passed (e.g., via conductive structures including metal layers in the substrate  204 ) to one or more conductive contacts (e.g., a conductive contact  304  and/or a conductive contact  306  on the side  313  of the substrate and/or one or more conductive contacts such as conductive contact  312  on the side  311  of the substrate) on the substrate  204  for output to other devices and/or components (e.g., via a connector such as a flexible printed circuit attached to one or more of the conductive contacts). 
     In one or more implementations, the microphone module  202  may also include a circuitry block  308 . For example, the circuitry block  308  may be coupled to the conductive contact  312  on the side  311  of the substrate  204 , and may include one or more conductive vias  310  that extend vertically away from the substrate  204  to one or more conductive contacts, such as conductive contact  314  on a top surface of the circuitry block  308 . In various implementations, the microphone module, may be provided with any subset, or all of the conductive contacts of  FIG.  3   , and/or one or more other conductive contacts or mechanisms such as solder balls. For example, in one or more implementations in which the microphone module  202  includes the circuitry block  308  on the conductive contact  312 , the microphone module  202  may omit the conductive contact  304  and the conductive contact  306 . In other examples, the microphone module  202  may include the conductive contact  304  and the conductive contact  306  and omit the conductive contact  312  and/or the circuitry block  308 . Any or all of the conductive contacts of  FIG.  3    may be electrically coupled to device circuitry (e.g., a volatile and/or non-volatile memory, one or more processors, etc.) of the electronic device  100  via a connector, such as a flexible printed circuit attached to one or more of the conductive contacts. 
       FIG.  4    illustrates an example of the microphone module  202  in which a resistive vent  400  (also referred to herein as a resistive filter) is disposed over the opening  209  on the side  311  of the substrate  204 . For example, the resistive vent  400  of  FIG.  4    includes a porous membrane that spans over the opening  209  and that allows airflow therethrough while prevent passage of sound there through. In this example, the resistive vent  400  is attached to the substrate  204  on the side  311 . As illustrated in  FIG.  4   , the resistive vent  400  spans over the opening  209  and the airflow  333  may flow (e.g., due to motion of the sound-responsive element  316 ), through the opening  209  and through the resistive vent  400 , between the sealed volume  301  and the environment external to the microphone module on the side  311  of the substrate  204  (e.g., the internal volume  222  of the electronic device  100  in one or more implementations). In the example of  FIG.  4   , the resistive vent  400  is disposed on the side  311  of the substrate. However, as shown in  FIG.  5   , the resistive vent  400  may be disposed over the opening  209  on the side  313  of the substrate  204  (e.g., attached to the surface of the substrate  204  on the side  313 ) in one or more implementations. 
     In the examples of  FIGS.  4  and  5   , a resistive vent  400  is provided over the opening  209 . In one or more implementations, the microphone module  202  may also, or alternatively, include an inductive vent (sometimes referred to as an inductive filter) over the opening  209 . As examples,  FIG.  6    illustrates an implementation in which the microphone module  202  includes an inductive vent  600  over the opening  209  on the side  311  of the substrate  204 , and  FIG.  7    illustrates an implementation in which the microphone module  202  includes an inductive vent  600  over the opening  209  on the side  313  of the substrate  204 . In the examples of  FIGS.  6  and  7   , the inductive vent  600  is attached to a surface of the substrate  204  (e.g. on the sides  311  and  313  respectively) and covers the opening  209 . As discussed in further detail hereinafter, the inductive vent  600  may include a channel within a substrate, the channel having a length that is substantially larger than the width of the channel, so that the inductive vent  600  acts as a low pass acoustic filter. 
     As illustrated in  FIGS.  4  and  5   , the airflow  333  may pass directly through a resistive vent  400  (e.g., through a porous membrane of the resistive vent). As illustrated in  FIGS.  6  and  7   , the airflow  333 , in an implementation in which an inductive vent  600  is provided, may include a portion that travels laterally through the inductive vent  600  (e.g., through a serpentine fluid pathway or channel in the inductive vent, as described in further detail hereinafter) in a direction substantially parallel to a surface of the substrate  204 , for at least a portion of the pathway. 
     In these examples, the non-porous membrane is mounted to the side  313  of the substrate  204  (e.g., mounted directly to the surface of the substrate  204  on the side  313  and laterally outward of the inductive vent  600  in  FIG.  7   ). In one or more other implementations, the microphone module  202  may include an inductive vent  600  over the opening  209  on the side  313  of the substrate  204 , and the non-porous membrane  216  may be mounted to the inductive vent  600 . 
     For example,  FIG.  8    illustrates an implementation in which the inductive vent  600  substantially spans the recess  214  in the substrate  204 , and the non-porous membrane  216  is attached to the inductive vent  600  (e.g., attached to the substrate  204  via the inductive vent  600 ). The wider implementation of the inductive vent  600  of  FIG.  8    may allow an relatively longer internal fluid pathway to extend between a first port coupled to the front volume  300  and a second port coupled to the opening  209 . As shown, the inductive vent  600  may include an opening  800  that is aligned with the opening  215  in the substrate  204 , to allow sound to pass through the opening  215  and the opening  800  to the sound-responsive element  316 . In one or more implementations, the inductive vent  600  includes a fluid pathway, such as a serpentine fluid pathway. The fluid pathway in the inductive vent  600  may, in one or more implementations, include a first portion formed on a first side of the opening  215  and a second portion formed on a second side of the opening  215 . In one or more implementations, the fluid pathway may extend around the opening  800 . For example in a serpentine fluid pathway, two or more segments of the serpentine fluid pathway may be spaced apart by a distance that is wider than a width of the opening  800 , or one or more segments of the serpentine fluid pathway may include a curve or a bend that passes around the opening  800  without fluidly coupling to the opening  800 . In one or more implementations, a port or a segment of the serpentine fluid pathway may fluidly couple to the opening  800 . 
     As shown in  FIG.  8   , in one or more implementations, the inductive vent  600  may be formed from a substrate  802  and a cover layer. For example, the substrate  802  may be a patterned substrate in which an etched channel partially defines a fluid pathway, such as a serpentine fluid pathway. For example, the etched channel may define two opposing sidewalls and a bottom wall that extends between the two opposing sidewalls, and the substrate  802  (e.g., prior to attachment to the substrate  204 ) may define an open channel without a top wall. As shown in  FIG.  8   , an adhesive layer  804  may attach the substrate  802  of the inductive vent  600  to the substrate  204  of the microphone module  202 . In this way, the substrate  204  and/or the adhesive layer  804  can form a cover layer for the inductive vent  600 . In one or more implementations, the adhesive layer  804  may cover the fluid pathway and (e.g., in combination with the substrate  204 ) define a wall, such as a top wall of the fluid pathway formed by the etched pattern in the substrate  802 . The adhesive layer  804  may be formed, for example, from a heat activated film, a pressure-sensitive adhesive, a curable liquid adhesive, or another adhesive material. In one or more other implementations described herein, the cover layer that forms the top wall of an etched pattern in the substrate of an inductive vent can include or incorporate a polymer layer such as a polyimide tape that is adhesively attached to the substrate of the inductive vent. As shown in  FIG.  8   , the adhesive layer  804  may adhesively attach the substrate  204  to the side  313  of the substrate  204 , within the recess  214 . In this example, the non-porous membrane  216  is attached to the substrate  204  of the inductive vent  600 . 
     In the example of  FIG.  8   , the inductive vent  600  is disposed on the side  313  of the substrate  204 , and the microphone module  202  is provided without a resistive vent. However, in one or more other implementations, the microphone module  202  may include the inductive vent  600  disposed on the side  313  of the substrate  204  and a resistive vent over the opening  209 . 
     For example,  FIG.  9    illustrates an example implementation of the microphone module  202  in which the microphone module  202  includes an inductive vent  600  disposed over the opening  209  on the side  313  of the substrate  204 , and a resistive vent  400  over the opening  209  on the side  311  of the substrate  204 . In this example, the airflow  333  passes directly through the resistive vent  400 , through the opening  209 , and laterally through the inductive vent  600  in a direction substantially parallel to a surface of the substrate  204 . In this example, the non-porous membrane  216  is attached to the inductive vent  600 . 
       FIG.  10    illustrates another example implementation in which the microphone module  202  includes a resistive vent over the opening  209  on the side  311  of the substrate  204 . In the example, of  FIG.  10   , a circuitry block  1000  (e.g., an input/output (I/O) block) is disposed over the opening  209  on the side  311  of the substrate  204 . In this example, the circuitry block  1000  includes a conductive via  1002  extending from the conductive contact  312  to a conductive contact  1004  on a top surface of the circuitry block  1000 . In this example, the circuitry block  1000  also forms a resistive vent over the opening  209 . In this example, the resistive vent is disposed in the circuitry block. For example, the resistive vent may be formed by a membrane  1006  (e.g., a porous membrane) that spans across a central opening  1008  in the circuitry block  1000 . 
     In the example of  FIG.  10   , the circuitry block  1000  is disposed on the side  311  of the substrate, and the microphone module  202  may be provided without an inductive vent  600 , or may include an inductive vent  600  (e.g., an inductive vent as shown in  FIG.  7    or an inductive vent that spans the cavity  214  as in  FIG.  8   ) over the opening  209  on the side  313  of the substrate  204 . For example, in one or more implementations, the microphone module  202  may include a circuitry block  1000  including a resistive vent mounted over the opening  209  on the side  313  of the substrate  204 , and an inductive vent  600  over the opening  209  on the side  313  of the substrate  204 . In the example of  FIG.  10   , the microphone module  202  may be provided with the circuitry block  1000  over the opening  209  and without the circuitry block  308  (see, e.g.,  FIG.  3   ), or may include both the circuitry block  1000  over the opening  209  and the circuitry block  308  on the side  311  of the substrate  204 . For example, in an implementation in which the microphone module  202  includes both the circuitry block  1000  over the opening  209  and the circuitry block  308  on the side  311  of the substrate  204 , the circuitry block  1000  may be used to route electrical signals from the microphone circuitry to the conductive contact(s)  1004  on the top of the circuitry block  1000  (e.g., for transmission to other device circuitry, such as a processor, via an interface, such as a flexible printed circuit), and the circuitry block  308  may provide an additional input/output (I/O) block for embedding functional silicon die (e.g., to provide RF filtering or other processing for the microphone signals from the microphone module  202 . 
     Referring back to the example of  FIG.  9   , the microphone module  202  includes an inductive vent  600  disposed over the opening  209  on the side  313  of the substrate  204 , a resistive vent  400  over the opening  209  on the side  311  of the substrate  204 , and the non-porous membrane  216  is attached to the inductive vent  600  (e.g., to the substrate  802  of the inductive vent  600 ). In another example,  FIG.  11    illustrates an implementation in which the microphone module  202  includes an inductive vent  600  disposed over the opening  209  on the side  313  of the substrate  204 , a resistive vent  400  over the opening  209  on the side  311  of the substrate  204 , and the non-porous membrane  216  is attached directly to the substrate  204  (e.g., laterally outward of the location at which the inductive vent  600  is attached to the substrate  204 ). 
     In the example of  FIG.  11   , the resistive vent  400  is disposed on the side  311  of the substrate  204  (e.g., within the environment on that side of the substrate  204 , such as within the internal volume  222  of the electronic device  100 ) and the inductive vent  600  is disposed on the side  313  of the substrate  204  (e.g., within the sealed volume  301 ). In the examples of  FIGS.  9  and  11   , the microphone module  202  includes a resistive vent  400  over the opening  209  on the side  311  of the substrate  204 , and an inductive vent  600  over the opening  209  on the side  313  of the substrate  204 . In the examples of  FIGS.  9  and  11   , a venting path (e.g., a barometric equalization path) through the inductive vent  600  and the resistive vent  400  is illustrated by the airflow  333  that flows between the front volume  300 , through a channel in the inductive vent  600  and through a porous membrane in the resistive vent  400 , and the environment external to the microphone module on the side  311  of the substrate (e.g., an air reservoir formed by the internal volume  222  within the housing  106  of electronic device  100 ). 
       FIG.  12    illustrates another implementation of the microphone module  202 , in which the resistive vent  400  is disposed over the opening  209  on the side  313  of the substrate  204  (e.g., within the sealed volume  301 ) and the inductive vent  600  is disposed over the opening  209  on the side  311  of the substrate  204  (e.g., within the environment external to the microphone module on the side  311  of the substrate such as within the internal volume  222  within the housing  106  of electronic device  100 ). In the example of  FIG.  12   , the microphone module  202  includes an inductive vent  600  over the opening  209  on the side  311  of the substrate  204  and a resistive vent  400  over the opening  209  on the side  313  of the substrate  204 . 
     In various examples described herein, a resistive vent  400  is disposed on one side of the substrate  204 , and an inductive vent  600  is disposed on an opposing side of the substrate  204 . In one or more other implementations, an inductive vent and a resistive vent may be formed on the same side of the substrate  204 . For example,  FIG.  13    illustrates an implementation in which the inductive vent  600  is attached to the substrate  204  on the side  311  of the substrate  204 , and a resistive vent  400  is attached to the inductive vent  600  (e.g., on a side of the inductive vent that is opposite to the side of the inductive vent  600  that is attached to the substrate  204 ). As illustrated, in this arrangement, the airflow  333  may flow between the sealed volume  301  on the side  313  of the substrate  204  and the environment (e.g., internal volume  222  of the electronic device  100 ) on the side  311  of the substrate via the opening  209 , via a first port on the bottom of the inductive vent  600  adjacent the opening  209 , a fluid channel within the inductive vent  600  (e.g., including a portion that extends in a direction parallel to the surface of the substrate  204 ), a port on the top surface of the inductive vent  600 , and the resistive vent  400 . In this arrangement, the inductive vent  600  may be adhesively attached to the substrate  204  and the resistive vent  400  may be (e.g., adhesively) attached to the inductive vent  600 . In this arrangement, the inductive vent  600  may have a first port on a first side and fluidly coupled to the opening  209 , and a second port on an opposing second side and fluidly coupled to the resistive vent  400 . In the example of  FIG.  13   , the microphone module  202  includes an inductive vent  600  mounted over the opening  209  on the side  313  of the substrate  204 , and a resistive vent  400  mounted on the inductive vent  600 . 
       FIG.  14    illustrates another implementation in which an inductive vent and a resistive vent are formed on the same side of the substrate  204 . In the example of  FIG.  14   , the microphone module  202  includes the circuitry block  1000  having the central opening  1008  and the membrane  1006  on the side  311  of the substrate, and also includes an inductive vent  600  disposed over the opening  209  on the side  311  of the substrate. In this example, the inductive vent  600  is disposed within the central opening  1008  in the circuitry block  1000 . In the example of  FIG.  14   , the microphone module  202  includes a circuitry block  1000  mounted over the opening  209  on the side  311  of the substrate  204 , a resistive vent spanning opening (e.g., the central opening  1008 ) in the circuitry block, and an inductive vent  600  mounted over the opening  209  on the side  311  of the substrate  204  and within the opening in the circuitry block  1000 . 
     In various examples described herein in connection with  FIGS.  2 - 14   , the microphone module  202  includes an opening  215  (e.g., a first opening) that may be an acoustic port for the microphone module), and an opening  209  (e.g., a second opening) that provides a leak port from the front volume  300  to an environment on the side  311  of the substrate  204  (e.g., an internal volume  222  of the electronic device  100  outside of and fluidly separated from the back volume  210  of the microphone module). In one or more implementations, the microphone module may include another leak port between the front volume  300  and the back volume  210 . The other leak port may be formed by another opening (e.g., a third opening) in the substrate  204 , such as substantially between the opening  215  and the opening  209 . 
     For example,  FIG.  15    illustrates an implementation in which the microphone module  202  includes an inductive vent  600  mounted over the opening  209  on the side  313  of the substrate  204 , and an opening  1500  (e.g., a third opening) in the substrate  204 . In the example of  FIG.  15   , the inductive vent  600  also includes an opening  1502 . As shown, the opening  1502  in the inductive vent  600  may be aligned with the opening  1500  in the substrate  204  to fluidly couple the front volume  300  and the back volume  210 . In one or more implementations, the opening  1502  extends through the inductive vent  600  and the inductive filter also includes a fluid pathway (e.g., a serpentine fluid pathway) therewithin that extends around the opening  1502  without fluidly coupling with the opening  1502 . In this way, the substrate  204  can include an opening  209  that is covered by an inductive vent  600  and an opening  1502  that is uncovered. As illustrated in  FIG.  15   , the microphone module  202  may include an airflow pathway  1501  that includes a portion that flows directly between the sealed volume  301  and the back volume  210  (e.g., to provide the other leak port between the front volume  300  and the back volume  210 , such as to enable a linear frequency response for the microphone module), and a portion that flows within the inductive vent  600  (e.g., within a serpentine fluid pathway that extends around the opening  215  and the opening  1502 ) and between the sealed volume  301  and the environment on the side  311  of the substrate via the opening  209 . 
     In the implementation illustrated in of  FIG.  15   , the microphone module  202  having the opening  1500  in the substrate  204  and the opening  1502  in the inductive vent  600  may be provided without a resistive vent over the opening  209 , or may include a resistive vent  400 , a circuitry block  1000  including a resistive vent, and/or a circuitry block  308 , as described herein in connection with any of the implementations of  FIGS.  3 ,  4 ,  5 ,  8 ,  9 ,  10   , and/or  11 . For example, in one or more implementations, the microphone module  202  having the opening  1500  in the substrate  204  and the opening  1502  in the inductive vent  600  may include a resistive vent  400  over the opening  209  on the side  311  of the substrate  204 . As another example, in one or more implementations, the microphone module  202  having the opening  1500  in the substrate  204  and the opening  1502  in the inductive vent  600  may include a resistive vent that is disposed within a circuitry block  1000  attached to the side  311  of the substrate  204 . 
     In the examples of  FIGS.  6 - 14   , the microphone module  202  may include an inductive vent that is attached to the substrate  204 , such as by an adhesive material (e.g., an adhesive material that attaches a cover layer of the inductive vent to the substrate  204 . In one or more other implementations, the microphone module  202  may include an inductive filter that is formed, at least in part, within the substrate  204  (also referred to herein as a microphone substrate) of the microphone. For example,  FIG.  16    illustrates an implementation in which an inductive filter  1600  (also referred to herein as an inductive vent) is disposed in the substrate  204  and extends from the opening  215  to the opening  209 . 
     As shown in  FIG.  16   , the inductive filter  1600  may include a channel  1602  formed in the substrate  204 . For example, the channel  1602  may be an etched channel (e.g., a laser etched channel, a chemically etched channel, or the like) that follows a path, such as a serpentine path, within the substrate  204 . In one or more implementations, the channel  1602  may be an open channel having three sides formed by a groove in the substrate  204 , and may be closed by a cover layer attached to the substrate  204 . For example, the cover layer may include a cover  1604  (e.g., an outer layer, or outer cover layer, such as polyimide or other polymer layer) that is attached to the substrate  204  by an adhesive layer  1606 . For example, the adhesive layer  1606  may be a heat activated film, a pressure sensitive adhesive, a curable liquid adhesive, or other adhesive material. The channel  1602  may be, for example, a serpentine channel having one or more switchback segments, and may have a channel width and an channel length that is substantially larger (e.g., many times larger) than the channel width, as discussed in further detail hereinafter. 
     In the implementation of  FIG.  16   , the microphone module  202  having the inductive filter  1600  disposed in the substrate  204  may be provided without a resistive vent over the opening  209 , or may include a resistive vent  400 , a circuitry block  1000  including a resistive vent, and/or a circuitry block  308 , as in any of the implementations of  FIGS.  3 ,  4 ,  5 ,  8 ,  9 ,  10   , and/or  11 . For example, the microphone module  202  having the inductive filter  1600  disposed in the substrate  204  may include a resistive vent  400  over the opening  209  on the side  311  of the substrate  204 . In one or more implementations, the resistive vent may be a resistive vent that is disposed in a circuitry block  1000  mounted to the side  311  of the substrate  204 . 
     In the example of  FIG.  16   , the non-porous membrane  216  is mounted to the cover  1604  for the inductive filter  1600 . In other examples, the non-porous membrane  216  may be mounted directly to the side  313  of the substrate  204 . For example, the inductive filter  1600  may substantially span the width of the recess  214  as in the example of  FIG.  16   , or the inductive filter  1600  may have shorter lateral extent within the substrate  204 , and the non-porous membrane  216  may be attached directly to the substrate  204  laterally outward of the distal ends of the cover  1604  of the inductive filter  1600 . 
     In the example of  FIG.  16   , the substrate  204  is provided without an additional opening between the front volume  300  and the back volume  210 . However, in other implementations, the microphone module  202  having the inductive filter  1600  disposed in the substrate  204  and/or having a resistive vent and/or a circuitry block disposed thereon may include an additional opening, such as the opening  1500  of  FIG.  15    that extends between the sealed volume  301  and the back volume  210 . In these implementations, the opening  1500  may pass through the inductive filter  1600  without fluidly coupling to the channel  1602 . For example, one or more segments of the channel  1602  may be spaced apart, curved, and/or bent to pass around the opening  1500  without fluidly coupling to the channel  1602 . 
       FIG.  17    illustrates a cross-sectional side view of a resistive vent  400  in accordance with one or more implementations. As shown in  FIG.  17   , the resistive vent  400  may include a frame  1700  having a central opening  1701 . In one or more implementations, the central opening  1701  may be aligned with the opening  209  in the substrate  204  of the microphone module  202 . As shown, the resistive vent  400  may also include a membrane  1702 , such as a porous membrane (e.g., an expanded PTFE membrane) spanning the central opening  1701  in the frame  1700 . For example, the membrane  1702  may be a porous membrane which allows airflow therethrough but has a large acoustic impedance. When implemented in the microphone module  202 , the porous membrane  1702  may extend over the opening  209  in the substrate  204  as described herein in connection with various examples. Depending on the direction of airflow (e.g., airflow  333 ) through the membrane  1702  when installed over the opening  209 , a portion of the central opening  1701  on a first side of the membrane  1702  may form a first ingress or egress aperture  1706 , and a portion of the central opening  1701  on a second side of the membrane  1702  may form a second ingress or egress aperture  1708 . In one or more implementations, the frame  1700  may be formed from plastic, or another substrate, such as a printed circuit substrate material (e.g., a glass-reinforced epoxy such as FR4). 
       FIG.  18    illustrates a cross-sectional side view of the circuitry block  1000 , in accordance with one or more implementations. A top view of the circuitry block  1000  is also shown in  FIG.  18   . As shown in  FIG.  18   , the circuitry block  1000  may include a frame  1800 . In one or more implementations, the frame  1800  may be formed from plastic, or another substrate, such as a printed circuit substrate (e.g., a glass-reinforced epoxy such as FR4). As shown, the membrane  1006  may span a central opening  1008  in the frame  1800 . As shown, conductive vias  1002  may be formed in the frame  1800 . The conductive vias  1002  may each extend from a conductive contact (e.g., a solder pad)  1806  on a first side of the frame  1800  to a conductive contact  1004  (e.g., a solder pad) on an opposing second side of the frame  1800 . In the cross-sectional view of  FIG.  18   , two conductive vias  1002  can be seen. However, in the top view, six conductive contacts  1004  are shown indicating six respective conductive vias within the frame. However, this is merely illustrative, and the circuitry block  1000  can be provided with any suitable number of conductive vias and corresponding contact pads. Depending on the direction of airflow (e.g., airflow  333 ) through the membrane  1006  when installed over the opening  209 , a portion of the central opening  1008  on a first side of the membrane  1006  may form a first ingress or egress aperture  1802 , and a portion of the central opening  1008  on a second side of the membrane  1006  may form a second ingress or egress aperture  1804 . 
     As illustrated in the example of  FIG.  18   , in one or more implementations, when implemented in the microphone module  202 , the circuitry block  1000  may include at least one conductive via  1002  extending from a first contact pad (e.g., a conductive contact  312 ) on the first side (e.g., side  311 ) of the substrate  204 , away from the substrate  204  to a second contact pad (e.g., a conductive contact  1004 ) on a top surface of the circuitry block  1000 . In this example, the circuitry block  1000  includes a main body that forms the frame  1800  of a resistive filter and encompasses the at least one conductive via  1002 . 
       FIGS.  19 - 21    illustrate various simplified cross-sectional side views of an inductive filter  1900 . As examples, the inductive filters  1900  of  FIG.  19 ,  20   , or  21  may be implementations of the inductive vent  600  or the inductive filter  1600  described herein. As indicated in  FIG.  19   , an inductive filter  1900  may include a first port  1902  formed on a side  1903  (e.g., a first side) of the inductive filter  1900 , and a second port  1904  formed on a side  1905  (e.g., an opposing second side) of the inductive filter  1900 . As shown, a channel  1906  (e.g., an implementation of the channel  1602  of  FIG.  16    or an implementation of a channel within a separate substrate as in the examples of  FIGS.  6 ,  7 ,  8 ,  9 ,  10 ,  11 ,  12 ,  13 ,  14   , and/or  15 ) extends through a substrate  1909  (e.g., the substrate  204  or a separate inductive filter substrate) between the first port  1902  and the second port  1904 . For example, the first port  1902  may couple to the front volume  300  of the microphone module, and the second port  1904  may couple to the opening  209  in the substrate  204 . 
     In the example of  FIG.  20   , the first port  1902  and the second port  1904  of the inductive filter  1900  are both formed on a common side (e.g., side  1905  in this example) of the inductive filter  1900 . In the example of  FIG.  21   , the first port  1902  of the inductive filter  1900  is formed on an edge  2100  of the inductive filter  1900 , and the second port  1904  of the inductive filter is formed on a side  1905  of the inductive filter  1900 . The inductive filters of  FIGS.  19 ,  20 , and  21    may be implemented as the inductive vent/filter of any of the examples of  FIGS.  6 ,  7 ,  8 ,  9 ,  10 ,  11 ,  12 ,  13 ,  14   , and/or  15 . Although the channel  1906  is shown as a single linear channel segment in the examples of  FIGS.  19 - 20   , it is understood that the channel  1906  may be a serpentine channel or a channel having any other arrangement that extends the channel length relative to the width of the channel. 
     For example,  FIG.  22    illustrates a cross-sectional top view of the inductive filter  1900  in the arrangement of  FIG.  20   , in which the first port  1902  and the second port  1904  of the inductive filter  1900  are both formed on a side (e.g., both commonly formed on a side such as side  1905  or formed on opposing sides, such as sides  1903  and  1905 ) of the inductive filter  1900 .  FIG.  23    illustrates a cross-sectional top view of an example in which the first port  1902  of the inductive filter  1900  is formed on an edge  2100  of the inductive filter  1900 , and the second port  1904  of the inductive filter is formed on a side  1905  of the inductive filter  1900 . 
     As shown in  FIGS.  22  and  23   , the channel  1906  may be a serpentine channel that includes multiple parallel segments  2200  that extend between a bend  2202  and/or a bend  2204  to form switchback segments within the substrate  1909 . In the example of  FIGS.  22  and  23   , the first port  1902  may be an ingress port configured to fluidly couple to the opening  215  in the substrate  204  of the microphone module  202 . In the examples of  FIGS.  22  and  23   , the second port  1904  may be an egress port configured to fluidly couple to the opening  209  in the substrate  204  of the microphone module  202 . As shown in the example of  FIG.  22   , the first port  1902  may include multiple input channels  2206  that are each fluidly between the channel  1906  and the first port  1902 . As shown in the examples of  FIGS.  22  and  23   , the second port  1904  may include multiple output channels  2208  that are each fluidly coupled between the channel  1906  and the second port  1904 . 
       FIG.  24    illustrates a side view of the inductive filter  1900  of  FIGS.  21  and  23   , with the channel  1906  represented simply as a dashed line. The side view of  FIG.  24    shows how the inductive filter  1900  may be formed from the substrate  1909  in which the channel  1906  is formed, and a cover  2400 . As examples, the cover  2400  may be an implementation of the cover layer described above in connection with  FIG.  8    or the cover  1604  of  FIG.  16   . As shown, the cover  2400  may be attached to the side  1905  of the substrate  1909  by an adhesive material  2401 . As examples, the adhesive material  2401  may be an implementation of the adhesive layer  1606  of  FIG.  16   . 
       FIG.  25    illustrates a cross-sectional side view of the inductive filter  1900  in any of the implementations of  FIGS.  19 - 24   , in which the cross sections of several segments  2200  of the channel  1906  can be seen. For example, the cross-sectional view of  FIG.  25    may be taken along the cross section A-A of either of  FIG.  22  or  23   . Although not visible in the cross-section of  FIG.  25   , the substrate  1909  includes at least one ingress aperture (e.g., first port  1902 ) and at least one egress aperture (e.g., second port  1904 ), on the same face, different faces, and/or edges of the substrate  1909  (e.g., as indicated in  FIGS.  19 - 21   ). The adhesive material  2401  may be patterned such that ingress and egress ports from the channel  1906  are not blocked by the adhesive material. In one or more implementations, the channel  1906  may have a cross-sectional width  2409  (e.g., between two opposing sidewalls  2500 ) of between 10 microns and 100 microns, and may have a depth (e.g., between a side  1905  of the substrate  1909  and a floor  2502  of the channel  1906 ) of between 10 and 100 microns. In one or more implementations, the total length of the channel  1906  may be between 10 mm and 50 mm. In the example of  FIG.  25   , the inductive filter  1900  includes a patterned substrate (e.g., substrate  1909 ) and a cover layer attached to the patterned substrate, the cover layer defining a surface of a serpentine fluid pathway defined by the channel  1906 . In one or more implementations, the cover layer includes an outer layer (e.g., cover  2400 ) and an adhesive material  2401 , and the adhesive material  2401  extends into and partially defines a portion of the serpentine fluid pathway. In the example of  FIG.  25   , a portion of the adhesive material  2401  is in contact with the surface of the substrate  1909  on the side  1905 , and a portion  2503  of the adhesive material  2401  extends partially into the segments  2200  of the channel  1906 . 
       FIG.  26    illustrates a perspective view of a fluid pathway, including the channel  1906 , of the inductive filter  1900 , with the substrate  1909 , the cover  2400 , and the adhesive material  2401  removed for clarity, in accordance with one or more implementations. As shown in  FIG.  26   , the channel  1906  may form a serpentine fluid pathway having multiple switchbacks formed by segments  2200 , each extending between a bend  2202  and a bend  2204 . As shown, multiple input channels  2206  may extend in parallel between the first port  1902  and the channel  1906 . As shown, a portion  2600  of the channel  1906  may extend around the first port  1902  (e.g., an consequently around the opening  800  of  FIG.  8   ) without fluidly coupling to the first port  1902 . In one or more implementations, the first port  1902  may correspond to the opening  800  of  FIG.  8   . In the example of  FIG.  26   , the segments  2200  of the serpentine portion of the channel  1906  are evenly spaced and linear. However, in one or more implementations in which the inductive filter  1900  is provided with another opening, such as the opening  1502  of  FIG.  15   , one or more of the segments  2200  may have a different spacing and/or may include a curve or a bend around that other opening  1502 , without fluidly coupling to that opening  1502 . In the example of  FIG.  26   , the first port  1902  may fluidly couple to the opening  215  of the substrate  204  of a microphone module  202 , and the second port  1904  may fluidly couple to the opening  209  in the substrate  204 . It is appreciated that the number of segments  2200  illustrated in  FIG.  26    is illustrative, and more or fewer segments  2200  may be used. 
     As discussed herein in connection with various examples, such as the example of  FIG.  16   , in one or more implementations, an inductive filter (e.g., inductive vent  600 , inductive filter  1600 , and/or inductive filter  1900 ) may be at least partially defined in the substrate  204  of microphone module  202 .  FIG.  27    illustrates a cross-sectional side view of the substrate  204  in an implementation in which an inductive filter  1600  is partially defined in the substrate  204 , in accordance with one or more implementations. 
     As shown in  FIG.  27   , the substrate  204  may be a multi-layer substrate having one or more metal layers  2700 , one or more insulating layers  2702 , an insulating layer  2706 , and a metal layer  2704 . For example, the metal layers  2700  may be interconnected with each other (e.g., by one or more internal vias in the substrate) to form conductive pathways for operation of the microphone module  202 . In one or more implementations, the metal layer  2704  may be electrically isolated from the metal layers  2700  by the insulating layer  2706 , and may form a mask for formation of the channel  1906  in the insulating layer  2706 . For example, the metal layer  2704  may be a patterned metal layer that forms an etch mask for etching (e.g., laser etching) the channel into the insulating layer  2706 . As illustrated by the example of  FIG.  26   , in one or more implementations, the substrate  204  may be formed by a combination of patterning and laminating printed circuit board materials together so that the channel  1906  (e.g., an embedded serpentine channel) is formed therein. For example, the channel  1906  may be formed by a combination of patterning and laminating PCB materials together so that an embedded serpentine channel is formed in the resulting substrate. For example, the metal layer  2704  may be patterned and used as a mask for an etching process (e.g., laser etching or other etching process) that removes unmasked portions of the insulating layer  2706  and/or insulating layers  2702 . 
     As shown, the cover  2400  (which may be an implementation of the cover  1604 ) may be attached to the metal layer  2704 . For example, the adhesive material  2401  (which may be an implementation of the adhesive layer  1606 ) may be attached to the metal layer  2704  of the substrate  204  and may attach the cover  2400  thereto. In one or more implementations, the adhesive material  2401  may extend partially into the channel  1906  that is formed in the metal layer  2704  and the insulating layer  2706 , as illustrated, for example, in  FIG.  25   . As shown, the opening  215  and the opening  209  in the substrate  204  may pass through the one or more metal layers  2700 , the one or more insulating layers  2702 , the metal layer  2704 , and the insulating layer  2706 . In one or more implementations, the insulating layers  2702  and/or the insulating layer  2706  may be formed, for example, from a glass-reinforced epoxy laminate material, such as FR4. In the example of  FIG.  27   , the first port  1902  is fluidly coupled to the opening  215  and the second port  1904  is fluidly coupled to the opening  209 . 
       FIG.  28    illustrates an example of a partially manufactured state  204 ′ of the substrate  204 , at a stage when the insulating layers  2702  have not yet been removed to form the opening  215  and the opening  209 . In  FIG.  28   , a bottom view of the metal layer  2704  is also shown, highlighting openings  2800  in the metal layer  2704  that form the openings in the channel  1906  that can be covered by the cover  2400 . As shown, the metal layer  2704  of the substrate  204  may further define the multiple parallel input channels  2206  extending from the first port  1902  to the a serpentine fluid pathway formed by the channel  1906 . In the example of  FIG.  28   , a bottom view of the insulating layer  2706  is also shown, and a portion of a metal layer  2802  of the substrate  204  is visible through the etched channel in the insulating layer  2706 . 
     In accordance with one or more implementations, an inductive acoustic filter (e.g., inductive vent  600 , inductive filter  1600 , or inductive filter  1900 ) is provided that includes a substrate (e.g., substrate  204  or substrate  1909 ), an etched serpentine channel (e.g., channel  1602  or channel  1906 ) in a surface of the substrate and extending within the substrate from a first port  1902  in the substrate  204  to a second port  1904  in the substrate  204 , and a polymer cover layer (e.g., cover  1604 , or cover  2400 ) adhesively attached to the surface of the substrate over the etched serpentine channel. In one or more implementations, the polymer cover layer is adhesively attached to the surface of the substrate by an adhesive material (e.g., adhesive layer  1606  or adhesive material  2401 ) that includes a first portion that contacts the surface (e.g., the surface on side  1905 ) of the substrate and a second portion that extends into a portion of the etched serpentine channel (e.g., as shown in  FIG.  25   ). In one or more implementations, the adhesive material includes a heat activated film. In one or more implementations, the polymer cover layer is formed from polyimide. In one or more implementations, the etched serpentine channel has a cross-sectional width  2409  and a length that is substantially larger than the cross-sectional width  2409 . In this way, the inductive filter  1900  may act as a low pass acoustic filter. 
     In one or more implementations, the polymer cover layer includes an opening fluidly coupled to second port  1904  in the substrate. In one or more implementations, the polymer cover layer is configured for attachment to a microphone substrate (e.g., substrate  204 ) of a microphone module  202  with the opening in alignment with a leak port (e.g., opening  209 ) in the microphone substrate. In one or more other implementations, the substrate is the microphone substrate (e.g., substrate  204 ) of a microphone module  202 . In one or more implementations, the inductive acoustic filter also includes multiple parallel input channels  2206  extending from the first port  1902  to the etched serpentine channel. 
     In one or more implementations, an electronic device  100  includes a housing  106  defining an internal volume  222 , a microphone module  202  disposed within the internal volume  222 . In one or more implementations, the microphone module  202  includes a substrate  204 , a cover  208  mounted to the substrate  204 , where the cover  208  separates a back volume  210  of the microphone module  202  from the internal volume  222 . In one or more implementations, the microphone module  202  also includes a front volume  300  that is separated from the back volume  210  by a sound-responsive element  316  and that is fluidly coupled to a first opening (e.g., opening  215 ) in the substrate  204 . In one or more implementations, the microphone module also includes a non-porous membrane  216  that defines a sealed volume  301  that is fluidly coupled to the front volume  300  via the first opening, and that provides a liquid-resistant seal between the front volume  300  and an environment  219  external to the housing  106 . In one or more implementations, the microphone module also includes a second opening (e.g., opening  209 ) in the substrate that extends from the sealed volume  301  defined by the non-porous membrane  216 , through the substrate  204 , to the internal volume  222  of the housing  106  external to the cover  208 . In one or more implementations, the electronic device  100  also includes at least one of a resistive filter (e.g., resistive vent  400  or a resistive filter disposed in a circuitry block  1000 ) or an inductive filter (e.g., inductive vent  600 , inductive filter  1600 , or inductive filter  1900 ) mounted over the second opening in the substrate. 
     In one or more implementations, a microphone module  202  includes a substrate  204 , a cover  208  mounted to the substrate  204  and at least partially defining a back volume  210  of the microphone module  202 , and a front volume  300  that is separated from the back volume  210  by a sound-responsive element  316  and that is fluidly coupled to a first opening (e.g., opening  215 ) in the substrate  204 . In one or more implementations, the microphone module  202  also includes a non-porous membrane  216  that defines a sealed volume  301  that is fluidly coupled to the front volume  300  via the first opening, and that provides a liquid-resistant seal between the front volume  300  and a first environment (e.g., environment  219 ) external to the microphone module  202  on a first side (e.g., side  313 ) of the substrate  204 . In one or more implementations, the microphone module  202  also includes a second opening (e.g., opening  209 ) in the substrate  204  that extends from the sealed volume  301  defined by the non-porous membrane  216 , through the substrate  204 , to a second environment (e.g., internal volume  222 ) external to the microphone module on an opposing second side (e.g., side  311 ) of the substrate  204 . In one or more implementations, the microphone module  202  includes an inductive filter (e.g., inductive vent  600 , inductive filter  1600 , or inductive filter  1900 ) disposed between at least a portion of the non-porous membrane  216  and at least a portion of the substrate  204 , the inductive filter having a first port  1902  coupled to the front volume  300 , a second port  1904  coupled to the second opening in the substrate  204 , and a serpentine fluid pathway (e.g., formed by the channel  1906 ) from the first port  1902  to the second port  1904 . 
     In one or more implementations, the inductive filter is attached to the opposing second side (e.g., side  311 ) of the substrate by an adhesive material (e.g., adhesive material  2401 ). In one or more implementations, the inductive filter is entirely disposed within the sealed volume  301  defined by the non-porous membrane  216  (e.g., as shown in  FIGS.  7  and  11   ). In one or more implementations, the substrate  204  includes a recess  214 , the inductive filter is attached to the substrate  204  within the recess  214 , and the inductive filter spans substantially an entire width of the recess  214  (e.g., as in the examples of  FIGS.  8 ,  9 ,  15 ,  16 , and  27   ). In one or more implementations, the inductive filter further includes multiple parallel input channels  2206  extending from the first port  1902  to the serpentine fluid pathway. 
     In one or more implementations, a microphone module  202  may include a substrate  204 , a cover  208  mounted to the substrate  204  and at least partially defining a back volume  210  of the microphone module  202 , a front volume  300  that is separated from the back volume  210  by a sound-responsive element  316  and that is fluidly coupled to a first opening (e.g., opening  215 ) in the substrate  204 , a non-porous membrane  216  that defines a sealed volume  301  that is fluidly coupled to the front volume  300  via the first opening, and that provides a liquid-resistant seal between the front volume  300  and a first environment (e.g., environment  219 ) external to the microphone module on a first side (e.g., side  313 ) of the substrate  204 , a second opening (e.g., opening  209 ) in the substrate  204  that extends from the sealed volume  301  defined by the non-porous membrane  216 , through the substrate  204 , to a second environment (e.g., internal volume  222  of the electronic device  100 ) external to the microphone module  202  on an opposing second side (e.g., side  311 ) of the substrate; and an inductive filter (e.g., inductive filter  1600  or inductive filter  1900 ) at least partially defined in the substrate  204 , the inductive filter having a first port  1902  coupled to the second opening, a second port  1904  coupled to the second environment, and a serpentine fluid pathway (e.g., defined by the channel  1906 ) within the substrate  204  from the first port  1902  to the second port  1904 . 
     In one or more implementations, the serpentine fluid pathway is defined, in part, by a cover layer (e.g., cover  1604  or cover  2400 ) that is attached to the substrate  204  by an adhesive material (e.g., adhesive layer  1606  or adhesive material  2401 ). In one or more implementations, the adhesive material extends at least partially into the serpentine fluid pathway (e.g., as shown in  FIG.  25   ). In one or more implementations, the substrate  204  is a multi-layer substrate having a metal layer  2704 , and the adhesive material (e.g., adhesive layer  1606  or adhesive material  2401 ) is attached to the metal layer  2704  of the substrate  204 . In one or more implementations, the metal layer  2704  of the substrate  204  further defines multiple parallel input channels  2206  extending from the first port  1902  to the serpentine fluid pathway. 
     In one or more implementations, an electronic device  100  includes a housing  106  defining an internal volume  222 , a microphone module  202  disposed within the internal volume  222 . In one or more implementations, the microphone module  202  includes a substrate  204 , a cover  208  mounted to the substrate  204 , the cover  208  separating a back volume  210  of the microphone module  202  from the internal volume  222 , a front volume  300  that is separated from the back volume  210  by a sound-responsive element  316  and that is fluidly coupled to a first opening (e.g., opening  215 ) in the substrate  204 , a non-porous membrane  216  that defines a sealed volume  301  that is fluidly coupled to the front volume  300  via the first opening, and that provides a liquid-resistant seal between the front volume  300  and an environment  219  external to the housing  106 , a second opening (e.g., opening  209 ) in the substrate  204  that extends from the sealed volume  301  defined by the non-porous membrane  216 , through the substrate  204 , to the internal volume  222  of the housing external to the cover  208 , and an inductive filter (e.g., inductive vent  600 , inductive filter  1600 , or inductive filter  1900 ) disposed between at least a portion of the non-porous membrane  216  and at least a portion of the substrate  204 , the inductive filter having a first port  1902  coupled to the front volume  300 , a second port  1904  coupled to the second opening in the substrate  204 , and a serpentine fluid pathway (e.g., defined by the channel  1906 ) from the first port to the second port. 
       FIG.  29    illustrates a flow diagram of an example process for operating a vented liquid-resistant microphone of an electronic device, in accordance with one or more implementations. For explanatory purposes, the process  2900  is primarily described herein with reference to the electronic device  100  and the microphone module  202  of  FIGS.  1 - 28   . However, the process  2900  is not limited to the electronic device  100  and the microphone module  202  of  FIGS.  1 - 28   , and one or more blocks (or operations) of the process  2900  may be performed by one or more other components and other suitable devices. Further for explanatory purposes, the blocks of the process  2900  are described herein as occurring in serial, or linearly. However, multiple blocks of the process  2900  may occur in parallel. In addition, the blocks of the process  2900  need not be performed in the order shown and/or one or more blocks of the process  2900  need not be performed and/or can be replaced by other operations. 
     In the example of  FIG.  29   , at block  2902 , sound may be received from an environment (e.g., environment  219 ) external to an electronic device (e.g., electronic device  100 ) at a sound-responsive element (e.g., sound-responsive element  316 ) of the liquid-resistant microphone (e.g., microphone module  202 ) through a non-porous membrane (e.g., non-porous membrane  216 ) of the liquid-resistant microphone and through first opening (e.g., opening  215 ) in a substrate (e.g., substrate  204 ) of the liquid-resistant microphone. 
     At block  2904 , an electronic signal may be generated based on a motion of the sound-responsive element due to the received sound. In one or more implementations, the motion of the sound-responsive element due to the received sound causes airflow (e.g., airflow  333 ) through a second opening (e.g., opening  209 ) in the substrate between a front volume (e.g., front volume  300 ) of the liquid-resistant microphone that is at least partially defined by the non-porous membrane and an interior cavity (e.g., internal volume  222  within the housing  106 ) of the electronic device that is separated from a back volume (e.g., back volume  210 ) of the liquid-resistant microphone by a cover (e.g., cover  208 ) mounted to the substrate. 
     In various implementations, the airflow passes through at least one of a resistive filter (e.g., a resistive vent  400  or a resistive filter mounted in a circuitry block  1000 ) or an inductive filter (e.g., inductive vent  600 , inductive filter  1600 , and/or inductive filter  1900 ) mounted over the second opening in the substrate, as described in, for example, any of  FIGS.  3 - 16   ). In one or more implementations, a portion of the airflow may also pass through a third opening (e.g., opening  1500 ) in the substrate that fluidly couples the back volume and the front volume (e.g., as described in connection with  FIG.  15   ). 
     In accordance with aspects of the subject disclosure, a microphone module is disclosed that includes a substrate having a first side and an opposing second side; a cover mounted to the first side of the substrate and at least partially defining a back volume of the microphone module; a front volume that is separated from the back volume by a sound-responsive element and that is fluidly coupled to a first opening in the substrate; a non-porous membrane that defines a sealed volume fluidly coupled to the front volume via the first opening, and that provides a liquid-resistant seal between the front volume and a first environment external to the microphone module on the opposing second of the substrate; and a second opening in the substrate that extends from the sealed volume defined by the non-porous membrane, through the substrate, to a second environment external to the microphone module on the first side of the substrate. 
     In accordance with other aspects of the subject disclosure, an electronic device is provided that includes a housing defining an internal volume; a microphone module disposed within the internal volume, the microphone module including a substrate; a cover mounted to the substrate, in which the cover separates a back volume of the microphone module from the internal volume; a front volume that is separated from the back volume by a sound-responsive element and that is fluidly coupled to a first opening in the substrate; a non-porous membrane that defines a sealed volume that is fluidly coupled to the front volume via the first opening, and that provides a liquid-resistant seal between the front volume and an environment external to the housing; and a second opening in the substrate that extends from the sealed volume defined by the non-porous membrane, through the substrate, to the internal volume of the housing external to the cover. 
     In accordance with other aspects of the subject disclosure, a method of operating a liquid-resistant microphone of an electronic device is provided, the method including receiving sound from an environment external to the electronic device at a sound-responsive element of the liquid-resistant microphone through a non-porous membrane of the liquid-resistant microphone and through first opening in a substrate of the liquid-resistant microphone; and generating an electronic signal based on a motion of the sound-responsive element due to the received sound. The motion of the sound-responsive element due to the received sound causes airflow through a second opening in the substrate between a front volume of the liquid-resistant microphone that is at least partially defined by the non-porous membrane and an interior cavity of the electronic device that is separated from a back volume of the liquid-resistant microphone by a cover mounted to the substrate. 
     Various functions described above can be implemented in digital electronic circuitry, in computer software, firmware or hardware. The techniques can be implemented using one or more computer program products. Programmable processors and computers can be included in or packaged as mobile devices. The processes and logic flows can be performed by one or more programmable processors and by one or more programmable logic circuitry. General and special purpose computing devices and storage devices can be interconnected through communication networks. 
     Some implementations include electronic components, such as microprocessors, storage and memory that store computer program instructions in a machine-readable or computer-readable medium (alternatively referred to as computer-readable storage media, machine-readable media, or machine-readable storage media). Some examples of such computer-readable media include RAM, ROM, read-only compact discs (CD-ROM), recordable compact discs (CD-R), rewritable compact discs (CD-RW), read-only digital versatile discs (e.g., DVD-ROM, dual-layer DVD-ROM), a variety of recordable/rewritable DVDs (e.g., DVD-RAM, DVD-RW, DVD+RW, etc.), flash memory (e.g., SD cards, mini-SD cards, micro-SD cards, etc.), magnetic and/or solid state hard drives, ultra density optical discs, any other optical or magnetic media, and floppy disks. The computer-readable media can store a computer program that is executable by at least one processing unit and includes sets of instructions for performing various operations. Examples of computer programs or computer code include machine code, such as is produced by a compiler, and files including higher-level code that are executed by a computer, an electronic component, or a microprocessor using an interpreter. 
     While the above discussion primarily refers to microprocessor or multi-core processors that execute software, some implementations are performed by one or more integrated circuits, such as application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). In some implementations, such integrated circuits execute instructions that are stored on the circuit itself. 
     As used in this specification and any claims of this application, the terms “computer”, “processor”, and “memory” all refer to electronic or other technological devices. These terms exclude people or groups of people. As used in this specification and any claims of this application, the terms “computer readable medium” and “computer readable media” are entirely restricted to tangible, physical objects that store information in a form that is readable by a computer. These terms exclude any wireless signals, wired download signals, and any other ephemeral signals. 
     To provide for interaction with a user, implementations of the subject matter described in this specification can be implemented on a computer having a display device as described herein for displaying information to the user and a keyboard and a pointing device, such as a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. 
     Many of the above-described features and applications are implemented as software processes that are specified as a set of instructions recorded on a computer readable storage medium (also referred to as computer readable medium). When these instructions are executed by one or more processing unit(s) (e.g., one or more processors, cores of processors, or other processing units), they cause the processing unit(s) to perform the actions indicated in the instructions. Examples of computer readable media include, but are not limited to, CD-ROMs, flash drives, RAM chips, hard drives, EPROMs, etc. The computer readable media does not include carrier waves and electronic signals passing wirelessly or over wired connections. 
     In this specification, the term “software” is meant to include firmware residing in read-only memory or applications stored in magnetic storage, which can be read into memory for processing by a processor. Also, in some implementations, multiple software aspects of the subject disclosure can be implemented as sub-parts of a larger program while remaining distinct software aspects of the subject disclosure. In some implementations, multiple software aspects can also be implemented as separate programs. Finally, any combination of separate programs that together implement a software aspect described here is within the scope of the subject disclosure. In some implementations, the software programs, when installed to operate on one or more electronic systems, define one or more specific machine implementations that execute and perform the operations of the software programs. 
     A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including as a stand alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network. 
     It is understood that any specific order or hierarchy of blocks in the processes disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes may be rearranged, or that all illustrated blocks be performed. Some of the blocks may be performed simultaneously. For example, in certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the aspects described above should not be understood as requiring such separation in all aspects, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. 
     In one aspect, a term coupled or the like may refer to being directly coupled. In another aspect, a term coupled or the like may refer to being indirectly coupled. 
     Terms such as top, bottom, front, rear, side, horizontal, vertical, and the like refer to an arbitrary frame of reference, rather than to the ordinary gravitational frame of reference. Thus, such a term may extend upwardly, downwardly, diagonally, or horizontally in a gravitational frame of reference. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the subject disclosure. 
     The predicate words “configured to”, “operable to”, and “programmed to” do not imply any particular tangible or intangible modification of a subject, but, rather, are intended to be used interchangeably. For example, a processor configured to monitor and control an operation or a component may also mean the processor being programmed to monitor and control the operation or the processor being operable to monitor and control the operation. Likewise, a processor configured to execute code can be construed as a processor programmed to execute code or operable to execute code 
     A phrase such as an “aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. A phrase such as an aspect may refer to one or more aspects and vice versa. A phrase such as a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A phrase such as a configuration may refer to one or more configurations and vice versa. 
     The word “example” is used herein to mean “serving as an example or illustration.” Any aspect or design described herein as “example” is not necessarily to be construed as preferred or advantageous over other aspects or design 
     All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.” Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim.

Metadata:
Filing Date: 20220211
Publication Date: 20240123
Grant Date: 20240123
Priority Date: 20220211
Inventors: MINERVINI, ANTHONY D.
HRUDEY, PETER C.
HATIPOGLU, Gokhan
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R1/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/086", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2201/003", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01H11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/04", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 87558322