Mwm Acoustics, LLC

Harman International Industries, Inc.

Other

Mwm Mobile Products, LLC

Christopher Todd Welsh

Alan Dean Michel

John C Baumhauer, Jr

Jeffrey Phillip McAteer

Medford Alan Dyer

Larry Allen Marcus

Joshua R Barber

Joshua James Barr

Michael Thomas Frank

A passive sound pressure level (SPL) limiter is provided that can be used with audio sources of varying drive levels and headphones or earphones of varying sensitivity. The SPL limiter includes a control circuit and left and right channel limiting circuits, each of which includes a pair of FETS. The SPL limiter may include a balancing circuit that separates the control signal output by the control circuit into left and right channel control signals. The SPL limiter may also include a microphone, for example integrated into an earpiece cable.

Passive sound pressure level limiter with balancing circuit

A passive sound pressure level (SPL) limiter is provided that can be used with audio sources of varying drive levels and headsets, earbuds, etc. of varying sensitivity. The SPL limiter includes a control circuit that includes a rectifier and, in most configurations, a step-up transformer. The SPL limiter also includes a limiting circuit that utilizes a transistor to shunt current from the audio source in proportion to a control signal output by the control circuit. The control circuit may further include a low pass filter, for example an RC filter, and one or more fast limit diode paths. The limiting circuit may further include a feedback network to increase the linear behavior of the limiting circuit.

Passive sound pressure level limiter

An earphone device capable of achieving sound bandwidths beyond the 150-7000 Hz wideband range, and configured for supra-concha or supra-aural placement. The earphone comprises at least two frequency range receivers positioned within a housing. In at least one embodiment, the earphone is capable of achieving a super-wideband range by physically combining a low frequency range receiver and a high frequency range receiver in a space-efficient and acoustically advantageous manner.

Earphone for wideband communication

A surface mountable package for use with an audio transducer is provided. In addition to the audio transducer, the surface mountable package includes a substrate, a cover, and a transducer support frame mounted within, and attached to, the substrate and cover. The support frame includes one or more cavities that, in combination with the audio transducer, substrate and cover, define the front and rear acoustic cavity volumes.

Transducer package with interior support frame

An omnidirectional electret condenser microphone element with improved low frequency background ambient acoustical noise rejection is provided. The omnidirectional electret condenser microphone element includes a plurality of passageways in acoustic series that couple at least one acoustic aperture of the microphone element to an acoustic cavity formed within the microphone element. At least one of said plurality of passageways is of a predefined size that is determined to provide the desired response roll-off within a predefined frequency range. In at least one preferred configuration, the roll-off resulting from the plurality of passageways is greater than 2.0 dB between 300 and 100 Hz. In at least one alternate preferred configuration, the roll-off resulting from the plurality of passageways is greater than 3.0 dB between 300 and 100 Hz.

Controlled leakage omnidirectional electret condenser microphone element

A surface mountable transducer package is provided, the design of which allows a thin package profile to be achieved. An encapsulation layer bonds to a surface of each of the terminal pads and encapsulates a portion of the transducer and at least a portion of the signal processing IC.

Transducer package with transducer die unsupported by a substrate

A transducer package fabrication process is provided, the completed transducer package achieving a thin package profile. The fabrication process utilizes an encapsulation material to eliminate the need for a transducer support substrate, the encapsulation material isolating the terminal pads from one another while holding the transducer and signal processing IC in position.

Method for fabricating a transducer package with the transducer die unsupported by a substrate

The microphone system for communication devices that comprises an electric circuit comprising two microphone elements connected to a signal flow processor. This processor uses a digital signal processor or comparable analog circuitry to provide a particular electrical time delay (&#x3c4;) to one of the microphone elements (nearest the ear or loudspeaker) and a compatible amplitude gain (Gm) to the other microphone element (nearest the user's mouth) in order to substantially reduce the external acoustic coupling and echo of communication devices in the receive and doubletalk state. Further, this processing system allows the microphone system to reduce the pickup of ambient noise in the send and idle state, while still being sensitive to the user's speech.

Microphone system for communication devices

A telephone handset that includes both a speaker and a secondary flux coil is provided. The secondary flux coil provides improved inductive coupling between the handset and a hearing aid. Due to the wiring configuration of the handset, the speaker and the secondary flux coil can be independently filtered, thus providing means for independently optimizing the performance of both the speaker and the secondary flux coil. Suitable filters include both passive circuits and digital signal processors.

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Fishers, IN, United States of America

Christopher Todd Welsh