U.S. Philips Corporation

U.S. Phillips Corporation

Paul A Beijer

Ronaldus Maria Aarts

Peter Sofrides Viet

Adriaan Johannes Rijnberg

Jan Tiesinga

Johannes At Driessen

Robertus T Toonen Dekkers

A stereophonic audio signal processing arrangement for variably enhancing a stereo image, wherein the stereo image enhancement is reduced at high signal levels so as to reduce distortion. The arrangement is used in a stereophonic audio reproduction system for enhancing the stereo image, which system may be part of an audio-visual reproduction system.

Arrangement, a system, a circuit and a method for enhancing a stereo

Known is a telecommunications system comprising a near end and a far end subscriber unit communicating with each other via a transmission channel, at least the near end subscriber being arranged for handsfree communication. In the known system, the near end subscriber unit comprises a duplex controller controlling the near end subscriber unit to three stable modes, a transmit mode, a receive mode, and an idle mode. The known subsciber unit operates in half-duplex mode and has speech and noise detectors for the transmit and receive paths, and a speech level comparator controlling the mode switching. At mode switching, suitable gain adaptation is done in the transmit and receive path so as to prevent howling in handsfree mode. The known duplex controller does not operate satisfactorily if the near end speaker is at a relatively large distance from the microphone. A telecommunications system is provided that satisfactorily operates when the near end speaker is a relatively large distance from the microphone. Time constants of the system are influenced when the far end speaker stops talking and the near end speaker takes over such that no speech loss occurs at the far end.

Telecommunications system, a subscriber unit, and a television set

Power-supply and communication

An audio amplifier having a volume-dependent tone control which is inexpensive and hardly distorts the audio signal. A filter in the signal path of the audio amplifier determines the tone control at low volumes. The bass tones and possibly treble tones are then amplified to a greater extent than the mid-range tones. With an increasing volume, a continuously controllable amplifier stage increasingly compensates this tone control. To this end a linear feedback path is arranged across this amplifier stage, with a pole in or near the frequency range of the bass and mid-range tones.

Audio amplifier arrangement having a volume dependent tone control

Growing community of inventors

Eindhoven, Netherlands

Paul A Beijer