Eric L Shumard

US Patent:

8249265, Aug 21, 2012

Filed:

Sep 17, 2007

Appl. No.:

11/856406

Inventors:

Eric L. Shumard - Indianapolis IN, US

International Classification:

A61F 11/06

US Classification:

381 711, 381 941, 381 95

Abstract:

A system and method for actively changing the sound perceived by listeners in an audio environment. A single transducer is used as both a sensing microphone and as an output driver. In one embodiment, the invention is implemented as an active noise cancellation system. The sensed noise signals are phase shifted to provide a cancellation effect, combined with the desired audio program signals, and output to the transducer, thereby reducing the level of unwanted noise heard by they listener. In other embodiments, the system can be used to sense the frequency response of a listening room and make appropriate equalization adjustments to the output.

US Patent:

59516259, Sep 14, 1999

Filed:

Jun 30, 1997

Appl. No.:

8/885249

Inventors:

Victor J. Duvanenko - Indianapolis IN
Eric Shumard - Indianapolis IN

Assignee:

Truevision, Inc. - Santa Clara CA

International Classification:

G06F 738

US Classification:

708290

Abstract:

An interpolated lookup table circuit includes an input port for receiving an input signal having a first plurality of bits (N bits) including a first portion (Q bits) and a second portion (N-Q bits), a lookup table (LUT) having a plurality of entries wherein each of the plurality of entries has a second plurality of bits including a third portion (V bits) and a fourth portion (D bits), selection means operatively coupled to the input port and responsive to at least the first portion of the input signal which selects one of the plurality of LUT entries based on the first portion of the lookup table input signal. The interpolated LUT circuit also includes a combiner operatively coupled to the input port and the LUT wherein the combiner combines the second portion of the input signal, the fourth portion of the selected LUT entry, and the third portion of the second plurality of bits of the selected LUT entry to provide an interpolated LUT output signal which is input to a rounding circuit wherein the interpolated LUT output signal is rounded or truncated to provide a rounded interpolated LUT output signal.