4,066,842

43.88.Tj METHOD AND APPARATUS FOR CANCEL- LING ROOM REVERBERATION AND NOISE PICKUP

Jont Brandon Allen, assignor to Bell Telephone Laboratories, In corporated

3 January 1978 (Class 179/1 P); filed 27 April 1977

The invention is a signal processing unit that can discriminate between desired speech signals in a room and the unwanted distor- tion introduced by reverberation and noise. Two separated micro- phones are employed with their outputs filtered into very narrow bands. "Early and late echo signals are separated by employing... fundamental cross-correlation difference between the echo signals,

and reverberations are removed by equalizing the early echo signals through a co-phase and add operation and by attenuating the late echo signals." Your reviewer does not pretend to be competent to understand the subsequent analysis and functional description. However, the patent is written in clear, declarative English and should be studied by anyone interested in speech communication and sound reinforcement.-GLA

4,107,462

43.88.Tj ELECTROVENTRILOQUIST

Satya Pal Asija, St. Paul, Minnesota 15 August 1978 (Class 179/1 VC); filed 9 June 1977

This is a speech amplification system in which a throat micro- phone is worn by the ventriloquist and the loudspeaker is mounted in the lifelike dummy. A foot switch is provided for turning the microphone channel on and off. A magnetic tape player plays prerecorded dialogue material through the system with time gaps for the ventriloquist to fill in. The physical features of the dummy are illuminated by interior lamps responding to peaks in the audio signal supplied to the 1oudspeaker.-DWM

4,107,461

43,88,Vk ENVIRONMENT FOR DEMONSTRATING A

STEREO LOUDSPEAKER SYSTEM

Amar G. Bose, assignor to Bose Corporation 15 August 1978 (Class 179/1 GA); fried 9 June 1977

The invention is a semicubicle for demonstrating loudspeaker systems.-GLA

4,112•55

43.88.Vk ROTA-PHONIC SYSTEM FOR STEREO

QUADROPHONIC SOUND SYSTEM

Warren A. Draw, assignor to Elizabeth Draw 5 September 1978 (Class 179/1 GQ); filed 18 May 1977

This is the third patent in this general category that your review- er has seen in the past year. What is this strange fascination with loudspeakers connected to motorized commutators? One can only assume that the disco craze is responsible.-GLA

4,118,599

43.88.Vk STEREOPHONIC SOUND REPRODUCTION

SYSTEM

Makoto lwahara and Toshinori Mori, assignors to Victor Company of Japan, Limited

3 October 1978 (Class 179/1.G); filed 25 February 1977

This is an interesting patent, full of matrix diagrams and transfer functions. "The invention relates to reproduction of original sound sources by utilizing a monaural-to-binaural signal converter to local- ize the virtual sound sources at desired location in a listening area, in combination with a crosstalk cancellation converter to minimize

the effect of crosstalk when the binaural signals are reproduced in the listening area."-GLA

3,987,258

43.88.Wrn WATER-PROOF SOUND APPARATUS

Katsumi Tsutsui, and Takeuki Yamamoto, assignors to Matsushita Electric Industrial Company

19 October 1976 (Class 179/179); filed 24 April 1975

A waterproof miniature radio receiver has a sealed case, a moisture-resistant diaphragm mounted in front of the loudspeaker, and a pressure equalizing valve which makes use of a fine-pore filter to keep out liquids.-GLA

1097 J. Acoust. Soc. Am. 65(4), Apr. 1979; 0001-4966/79/041097-01500.80; ̧ 1979 Acoust. Soc. Am.; Patent Reviews 1097

Redistribution subject to ASA license or copyright; see http://acousticalsociety.org/content/terms. Download to IP: 140.254.87.149 On: Sat, 20 Dec 2014 19:59:11