Abstract: An apparatus comprising: a microelectromechanical systems (MEMS) chip having a movable member coupled to a front chamber; and an attenuator chip coupled to the MEMS chip and having an array of attenuators arranged around a port that is open to the front chamber.

Abstract: A portable electronic device comprising: an enclosure having an enclosure wall that defines a first chamber, a second chamber and an acoustic opening from the first chamber or the second chamber; and an electroosmotic flow valve operable to open and close the acoustic opening.

Abstract: An acoustic device comprising: an enclosure defining an acoustic port and an acoustic pathway between the acoustic port and a transducer coupled to the enclosure; and an array of attenuators acoustically coupled to the acoustic pathway to absorb ultrasonic acoustic waves.

Abstract: A portable electronic device comprising: an enclosure having an enclosure wall that forms an interior chamber and a sound output port to an ambient environment; a transducer positioned within the interior chamber and dividing the interior chamber into a front volume chamber coupling a first side of the transducer to the sound output port and a back volume chamber coupled to a second side of the transducer; and an electromechanical valve comprising a number of flaps operable to open and close a vent to the interior chamber, the front volume chamber or the back volume chamber.

Abstract: A portable electronic device comprising: an enclosure having an enclosure wall that forms an interior chamber and a sound output port to an ambient environment; a transducer positioned within the interior chamber and dividing the interior chamber into a front volume chamber coupling a first side of the transducer to the sound output port and a back volume chamber coupled to a second side of the transducer; and an electromechanical valve comprising a number of flaps operable to open and close a vent to the interior chamber, the front volume chamber or the back volume chamber.

Abstract: A portable electronic device comprising: an enclosure having an enclosure wall that forms an interior chamber and an opening to an environment surrounding the enclosure wall; and a valve comprising a number of sliding actuators operable to open and close the opening to the environment surrounding the enclosure wall.

Abstract: A portable electronic device comprising: an enclosure having an enclosure wall that forms an interior chamber containing a transducer and a valve operable to open or close a vent to the interior chamber; and a particle removal mechanism coupled to the valve that is operable to drive particles away from the valve upon application of a current.

Abstract: Aspects of the subject technology relate to electronic devices having speakers such as microelectromechanical systems (MEMS) speakers. A MEMS speaker can include an electrostatically driven, corrugated MEMS structure to move air without a magnet, coil, or traditional speaker membrane, and thus provide a low-power, compact speaker with a large acoustically active area in a small volume. Neighboring folds in the corrugated MEMS structure may form pairs of MEMS electrodes that can be pushed together and/or pulled apart to deform the MEMS structure in a breathing motion that generates pressure differentials on opposing sides of the corrugated MEMS structure to generate sound. Additional modes of operation are described.

Abstract: Aspects of the subject technology relate to inductive acoustic filters for acoustic devices. An inductive filter may include a substrate, an etched serpentine channel in a surface of the substrate and extending within the substrate from a first port in the substrate to a second port in the substrate. The inductive filter may also include a polymer cover layer adhesively attached to the surface of the substrate over the etched serpentine channel. The inductive filter may be positioned over an opening in a substrate of an acoustic module, such as a microphone module or a speaker module.

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.

Abstract: A portable electronic device comprising: an enclosure having an enclosure wall that defines a first chamber, a second chamber and an acoustic opening from the first chamber or the second chamber; and an electroosmotic flow valve operable to open and close the acoustic opening.

Abstract: A portable electronic device comprising: an enclosure having an enclosure wall that forms an interior chamber and a sound output port to an ambient environment; a transducer positioned within the interior chamber and dividing the interior chamber into a front volume chamber coupling a first side of the transducer to the sound output port and a back volume chamber coupled to a second side of the transducer; and an electromechanical valve comprising a number of flaps operable to open and close a vent to the interior chamber, the front volume chamber or the back volume chamber.

Abstract: An acoustic device comprising: an enclosure defining an acoustic port and an acoustic pathway between the acoustic port and a transducer coupled to the enclosure; and an array of attenuators acoustically coupled to the acoustic pathway to absorb ultrasonic acoustic waves.

Abstract: A portable electronic device comprising: an enclosure having an enclosure wall that forms an interior chamber and an opening to an environment surrounding the enclosure wall; and a valve comprising a number of sliding actuators operable to open and close the opening to the environment surrounding the enclosure wall.

Abstract: A MEMS speaker can include an electrostatically driven, corrugated MEMS structure to move air without a magnet, coil, or traditional speaker membrane, and thus provide a low-power, compact speaker with a large acoustically active area in a small volume. Neighboring folds in the corrugated MEMS structure may form pairs of MEMS electrodes that can be pushed together and/or pulled apart to deform the MEMS structure in a breathing motion that generates pressure differentials on opposing sides of the corrugated MEMS structure to generate sound.

Abstract: An electronic device has an acoustic transducer with an acoustic diaphragm. The diaphragm has opposed first and second major surfaces. A front volume is positioned adjacent the first major surface. A back volume is positioned adjacent the second major surface. An elongated channel defines a barometric vent and extends from a first end fluidly coupled with the front volume to a second end fluidly coupled with the back volume, fluidly coupling the front volume with the back volume. The elongated channel may have a high aspect ratio (L/D), providing the vent with a substantial air mass. The elongated channel may be segmented to define a higher-order filter. For example, a segmented channel can have a cascade of repeating acoustic-mass and acoustic-compliance units, providing the barometric vent with additional degrees-of-freedom for tuning.

Abstract: An electronic device has an acoustic transducer with an acoustic diaphragm. The diaphragm has opposed first and second major surfaces. A front volume is positioned adjacent the first major surface. A back volume is positioned adjacent the second major surface. An elongated channel defines a barometric vent and extends from a first end fluidly coupled with the front volume to a second end fluidly coupled with the back volume, fluidly coupling the front volume with the back volume. The elongated channel may have a high aspect ratio (L/D), providing the vent with a substantial air mass. The elongated channel may be segmented to define a higher-order filter. For example, a segmented channel can have a cascade of repeating acoustic-mass and acoustic-compliance units, providing the barometric vent with additional degrees-of-freedom for tuning.

Abstract: Aspects of the subject technology relate to low noise microphone assemblies for electronic devices. A microphone assembly may include components for sensing sound, mounted on a substrate, under a cover disposed on the substrate. The components may receive sound through an opening in the substrate. The microphone assembly may include an interposer on the substrate. The interposer includes one or more contacts on a surface that is spatially separated from the surface of the substrate, in a direction perpendicular to the surface of the substrate. A first side of the substrate may be mounted to an inner surface of a housing of the electronic device. The components, the cover, and the interposer may be mounted to an opposing second side of the substrate. A flexible printed circuit may be coupled to the contacts on the surface of the interposer, and mechanically attached to a surface of the cover.

Abstract: A microphone assembly has an interconnect substrate and a microphone transducer coupled with the substrate. A lid overlies the microphone transducer. At least a portion of the lid is spaced from the substrate, defining an acoustic chamber for the microphone transducer. The lid can have a layer of discretized metal or other patterned conductor. The discretized layer of metal or other patterned conductor is configured to inhibit formation of eddy currents, as when exposed to electromagnetic radiation. The lid can be grounded. Microphone modules and electronic devices also are described.

Abstract: A microphone assembly has an interconnect substrate and a microphone transducer coupled with the substrate. A lid overlies the microphone transducer. At least a portion of the lid is spaced from the substrate, defining an acoustic chamber for the microphone transducer. The lid can have a layer of discretized metal or other patterned conductor. The discretized layer of metal or other patterned conductor is configured to inhibit formation of eddy currents, as when exposed to electromagnetic radiation. The lid can be grounded. Microphone modules and electronic devices also are described.