Plantronics, Inc.

Octiv, Inc.

Richard Hodges

Keith A McMillen

David M Roberts

Keith Edwards

Gordon Scott Simmons

Leif Hakan Claesson

Sreevathsa G Sreenivasa Reddy

A speakerphone having improved echo cancellation and sound output includes at least one directional microphone having at least one axis of sensitivity and at least one zone of insensitivity, and a speaker disposed in the zone of insensitivity of the microphone to radiate sound away from the microphone and towards a reflective surface, such as a desktop or wall, against which the speakerphone is disposed. A baseplate disposed adjacent to the speaker outlet can combine with the housing of the phone to form a flaring, right-angled horn having an inlet coupled to the outlet of the speaker and an outlet terminating at a periphery of the housing. A wall-mounting embodiment incorporates a unidirectional microphone with an axis of sensitivity oriented perpendicular to the wall, and a desktop-mounting embodiment includes an array of at least two bi-directional microphones having respective axes of sensitivity oriented parallel to the desktop.

Speakerphone with downfiring speaker and directional microphones

Methods and apparatus are described for use with a near-end telephone. The near-end telephone is operable to generate an outgoing signal directed to a far-end telephone and to receive an incoming signal generated at least in part by the far-end telephone. A first signal processor is operable to dynamically adjust a first signal level associated with the outgoing signal with reference to the first signal level. A second signal processor is operable to dynamically adjust a second signal level associated with the incoming signal with reference to the second signal level. The first and second signal processors are further operable to control a loop gain to inhibit loop instability.

Techniques for improving telephone audio quality

Various methods and apparatus are described for implementing effective echo suppression in a wide variety of telephony system architectures. These methods and apparatus include broadband and multi-band techniques for speech detection, estimation of near-end transmission path attenuation, and estimation of far-end transmission path attenuation and delay.

Echo suppression and speech detection techniques for telephony applications

Methods and apparatus are described for performing a variable sample rate conversion. A difference between a first sample rate associated with a first signal and a second sample rate associated with a second signal is tracked. A sample rate conversion ratio is adjusted in response to the difference. One of the first and second sample rates is converted using the conversion ratio.

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Oakland, CA, United States of America

Richard Hodges