Justin M Allen

US Patent:

6847930, Jan 25, 2005

Filed:

Jan 25, 2002

Appl. No.:

10/057104

Inventors:

Justin L. Allen - Mesa AZ, US
Steven M. Domer - Mesa AZ, US

Assignee:

Acoustic Technologies, Inc. - Mesa AZ

International Classification:

G10L 1102

US Classification:

704233, 704215

Abstract:

Voice activity is detected by comparing an analog signal with two voltage thresholds and producing data representing the energy of the signal. The data, in binary form, is compared with thresholds to determine voice activity. In accordance with another aspect of the invention, the thresholds are adjusted based upon statistical information. In accordance with another aspect of the invention, the data can be weighted to provide an indication of the quasi-RMS energy of an input signal. The input signal itself is not converted into digital form yet the data derived from the input signal has high resolution.

US Patent:

7295976, Nov 13, 2007

Filed:

Jan 25, 2002

Appl. No.:

10/056826

Inventors:

Steven M. Domer - Mesa AZ, US
Justin L. Allen - Mesa AZ, US
Franklyn H. Story - Chandler AZ, US
Kellie Michele Vanda - Chandler AZ, US

Assignee:

Acoustic Technologies, Inc. - Mesa AZ

International Classification:

G10L 15/00

US Classification:

704233, 704200

Abstract:

Voice activity is detected by comparing a signal with two thresholds and producing data representing the energy of the signal. The data, in binary form, is compared with thresholds to determine voice activity. In accordance with another aspect of the invention, the thresholds are adjusted based upon statistical information. In accordance with another aspect of the invention, the data can be weighted to provide an indication of the quasi-RMS energy of an input signal.

US Patent:

7561864, Jul 14, 2009

Filed:

Dec 3, 2006

Appl. No.:

11/566222

Inventors:

Ghassan Chehade Maalouli - Scottsdale AZ, US
Justin Lamar Allen - Mesa AZ, US
Keith Charles Palermo - Higley AZ, US

Assignee:

General Dynamics C4 Systems, Inc. - Scottsdale AZ

International Classification:

H04B 1/10

US Classification:

455286, 455 6713, 455296, 455310

Abstract:

An RF receiver () includes a channel estimator (). The channel estimator () includes a channel estimation filter (), error signal generator (), and normalized Least-Mean-Square (NLMS) filter-definition generator. The filter (), error generator () and NLMS filter-definition generator () function together as an adaptive estimator. An error signal () is formed with a received signal (). The filter () filters an estimated transmit signal () constructed from lower confidence decision data () and higher confidence known preamble data (). An adaptive filter definition () is formed in a feedback, loop which minimizes correlation between the estimated transmit signal () and the error signal (). A convergence signal () is modulated in synchronism with the changes between lower and higher confidence data in the estimated transmit signal ().

US Patent:

7649988, Jan 19, 2010

Filed:

Jun 15, 2004

Appl. No.:

10/868989

Inventors:

Seth Suppappola - Tempe AZ, US
Samuel Ponvarma Ebenezer - Tempe AZ, US
Justin L. Allen - Mesa AZ, US

Assignee:

Acoustic Technologies, Inc. - Mesa AZ

International Classification:

H04M 9/08

US Classification:

37940603

Abstract:

A background noise estimate based upon a modified Doblinger noise estimate is used for modulating the output of a pseudo-random phase spectrum generator to produce the comfort noise. The circuit for estimating noise includes a smoothing filter having a slower time constant for updating the noise estimate during noise than during speech. Comfort noise is smoothly inserted by basing the amount of comfort noise on the amount of noise suppression. A discrete inverse Fourier transform converts the comfort noise back to the time domain and overlapping windows eliminate artifacts that may have been produced during processing.

US Patent:

8565414, Oct 22, 2013

Filed:

Dec 30, 2010

Appl. No.:

12/930171

Inventors:

Justin L. Allen - Mesa AZ, US
Franklyn H. Story - Chandler AZ, US
Seth Suppappola - Tempe AZ, US

Assignee:

Acoustic Technologies, Inc. - Mesa AZ

International Classification:

H04M 1/00

US Classification:

379392, 37938702, 37938802, 37939001, 37940601

Abstract:

A telephone includes a transmit channel and a receive channel, each including a bank of sub-band filters having a VAD coupled one to each sub-band filter. Each VAD measures the spectral energy in a sub-band, compares the spectral energy to a first threshold, and produces an output signal representative of whether or not the first threshold is exceeded. The voice activity detector also includes a threshold circuit for calculating a dynamically adjustable noise threshold based upon averaged measured spectral energy. A wide band or system VAD monitors echo canceling circuitry to detect voice activity and double talk.

US Patent:

20020000875, Jan 3, 2002

Filed:

Jan 13, 2000

Appl. No.:

09/482293

Inventors:

Justin Allen - Mesa AZ, US
Samuel Thomasson - Gilbert AZ, US

International Classification:

H03B001/00

US Classification:

327/557000

Abstract:

The separation of a adjacent band pass filters is improved, without changing the filters, by inverting the output signals from alternate filters and not inverting the remaining output signals. All the output signals are then summed. The result is a deeper notch in the frequency response of adjacent filters.

US Patent:

20020097861, Jul 25, 2002

Filed:

Jan 25, 2001

Appl. No.:

09/769564

Inventors:

Franklyn Story - Chandler AZ, US
Samuel Thomasson - Gilbert AZ, US
Justin Allen - Mesa AZ, US
Judy Fong - Chandler AZ, US
Scott Harrow - Scottsdale AZ, US

Assignee:

Acoustic Technologies, Inc.

International Classification:

H04M001/00
H04M009/00

US Classification:

379/387020

Abstract:

An audio signal is divided into a plurality of bands prior to generating a shadow. The shadow is created by delaying the portion of the audio signal in at least one band by less than fifty milliseconds and combining the shadow signal with the portion of the audio signal. The portions, with any shadows, are combined to produce a reconstructed audio signal. The presence or absence of a shadow signal represents data or the data is represented by two or more shadow signals, in one or more bands. The period of delay of a portion in a band should not equal the period of the center frequency of that band. Preferably, the period of delay of a portion in a band does not equal the period of any frequency within the pass band.

US Patent:

20020141568, Oct 3, 2002

Filed:

Apr 2, 2001

Appl. No.:

09/824359

Inventors:

Samuel Thomasson - Gilbert AZ, US
Franklyn Story - Chandler AZ, US
Scott Harrow - Scottsdale AZ, US
Judy Fong - Chandler AZ, US
Justin Allen - Mesa AZ, US

Assignee:

Acoustic Technologies, Inc.

International Classification:

H04M001/00
H04M003/00

US Classification:

379/350000

Abstract:

Correlation is improved by comparing the output of a multiplier and low pass filter to a first threshold and incrementing a counter when the output from the filter exceeds the first threshold; comparing the output of the filter to a second threshold and decrementing the counter when the output is below a second threshold. Correlation is indicated by the count in the counter exceeding a predetermined amount.