Patents by Inventor William R. Morrell

William R. Morrell has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9008319
    Abstract: Sound pressure level limiter with anti-startle feature for audio systems are disclosed. The anti-startle feature may be implemented with a delta incident detector for detecting delta acoustic incidents that exceed a predetermined acoustic startle boundary, a delta limiter for determining an anti-startle gain, and an amplifier to apply the anti-startle gain to the input signal. The delta incident detector may detect delta incidents based on an estimated true SPL delivered by a transducer to a predetermined datum point. The estimated true SPL may be determined by based on a measured receiving frequency response of the transducer. An SPL limiter may also determine an SPL gain in response to detecting an SPL acoustic incident that exceeds a predetermined SPL threshold, and an amplifier may apply the SPL gain to the input signal to reduce it below the threshold.
    Type: Grant
    Filed: December 30, 2004
    Date of Patent: April 14, 2015
    Assignee: Plantronics, Inc.
    Inventors: Antony M W. Bayley, William R. Morrell, Iain J. McNeill, Kwangsee A. Woo
  • Patent number: 7242783
    Abstract: An audio limiting circuit capable of satisfying frequency dependent limits and time domain constraints, is disclosed. In one illustrative embodiment, an input node receives an unattenuated input signal and a system modeling filter predicts the amount, if any, by which the sound pressure level that would be generated by an acoustic transducer in response to the unattenuated input signal, would exceed one or more predetermined limits. In that embodiment, an energy detector separates the excess predicted sound pressure level into one or more frequency bands and calculates the average acoustic energy associated with each band. A gain logic block determines an attenuation factor based on whether one or more of the predetermined limits has been exceeded and the attenuation factor values are smoothed to minimize abrupt changes to the unattenuated input signal. A delay buffer delays the unattenuated input signal values.
    Type: Grant
    Filed: January 25, 2006
    Date of Patent: July 10, 2007
    Assignee: Plantronics, Inc.
    Inventors: William A. Weeks, William R. Morrell
  • Patent number: 7013011
    Abstract: An audio limiting circuit capable of satisfying frequency dependent limits and time domain constraints, is disclosed. In one illustrative embodiment, an input node receives an unattenuated input signal and a system modeling filter predicts the amount, if any, by which the sound pressure level that would be generated by an acoustic transducer in response to the unattenuated input signal, would exceed one or more predetermined limits. In that embodiment, an energy detector separates the excess predicted sound pressure level into one or more frequency bands and calculates the average acoustic energy associated with each band. A gain logic block determines an attenuation factor based on whether one or more of the predetermined limits has been exceeded and the attenuation factor values are smoothed to minimize abrupt changes to the unattenuated input signal. A delay buffer delays the unattenuated input signal values.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: March 14, 2006
    Assignee: Plantronics, Inc.
    Inventors: William A. Weeks, William R. Morrell
  • Patent number: 6252909
    Abstract: A communication system for sending a sequence of symbols on a communication link. The system includes a transmitter for placing information indicative of the sequence of symbols on the communication link and a receiver for receiving the information placed on the communication link by the transmitter. The transmitter includes a clock for defining successive frames, each of the frames including M time intervals, where M is an integer greater than 1. A modulator modulates each of M carrier signals with a signal related to the value of one of the symbols thereby generating a modulated carrier signal corresponding to each of the carrier signals. The modulated carriers are combined into a sum signal which is transmitted on the communication link. The carrier signals include first and second carriers, the first carrier having a different bandwidth than the second carrier.
    Type: Grant
    Filed: February 25, 1997
    Date of Patent: June 26, 2001
    Assignee: Aware, Inc.
    Inventors: Michael A. Tzannes, Peter Niels Heller, John P. Stautner, William R. Morrell, Sriram Jayasimha
  • Patent number: 5606642
    Abstract: An audio decompression system is disclosed. The corresponding compression system utilizes sub-band analysis filters whose bandwidths are chosen to approximate the critical bands of the human auditory system while avoiding the aliasing problems encountered in QMF filter banks designed to provide similar band splitting. One embodiment of the invention may be implemented on a digital computer. The computational requirements of the synthesis filters may be varied in response to the available computational resources of the computer, thereby allowing a single compressed audio signal to be played back in real time on a variety of platforms by trading off audio quality against available computational resources. Similar trade offs can be made in compressing an audio signal, thereby allowing a platform having limited computational capacity to compress a signal in real time.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: February 25, 1997
    Assignee: Aware, Inc.
    Inventors: John P. Stautner, William R. Morrell, Sriram Jayasimha
  • Patent number: 5408580
    Abstract: The compression system utilizes sub-band analysis filters whose bandwidths are chosen to approximate the critical bands of the human auditory system while avoiding the aliasing problems encountered in QMF filter banks designed to provide similar band splitting. One embodiment of the invention may be implemented on a digital computer. The computational requirements of the synthesis filters may be varied in response to the available computational resources of the computer, thereby allowing a single compressed audio signal to be played back in real time on a variety of platforms by trading off audio quality against available computational resources. Similar trade offs can be made in compressing an audio signal, thereby allowing a platform having limited computational capacity to compress a signal in real time.
    Type: Grant
    Filed: September 21, 1992
    Date of Patent: April 18, 1995
    Assignee: Aware, Inc.
    Inventors: John P. Stautner, William R. Morrell, Sriram Jayasimha
  • Patent number: RE40281
    Abstract: A communication system for sending a sequence of symbols on a communication link. The system includes a transmitter for placing information indicative of the sequence of symbols on the communication link and a receiver for receiving the information placed on the communication link by the transmitter. The transmitter includes a clock for defining successive frames, each of the frames including M time intervals, where M is an integer greater than 1. A modulator modulates each of M carrier signals with a signal related to the value of one of the symbols thereby generating a modulated carrier signal corresponding to each of the carrier signals. The modulated carriers are combined into a sum signal which is transmitted on the communication link. The carrier signals include first and second carriers, the first carrier having a different bandwidth than the second carrier.
    Type: Grant
    Filed: November 23, 2004
    Date of Patent: April 29, 2008
    Assignee: Aware, Inc.
    Inventors: Michael A. Tzannes, Peter N. Heller, John P. Stautner, William R. Morrell, Sriram Jayasimha
  • Patent number: RE42949
    Abstract: A communication system for sending a sequence of symbols on a communication link. The system includes a transmitter for placing information indicative of the sequence of symbols on the communication link and a receiver for receiving the information placed on the communication link by the transmitter. The transmitter includes a clock for defining successive frames, each of the frames including M time intervals, where M is an integer greater than 1. A modulator modulates each of M carrier signals with a signal related to the value of one of the symbols thereby generating a modulated carrier signal corresponding to each of the carrier signals. The modulated carriers are combined into a sum signal which is transmitted on the communication link. The carrier signals include first and second carriers, the first carrier having a different bandwidth than the second carrier.
    Type: Grant
    Filed: September 14, 2007
    Date of Patent: November 22, 2011
    Assignee: Hybrid Audio LLC
    Inventors: Michael A. Tzannes, Peter N. Heller, John P. Stautner, William R. Morrell, Sriram Jayasimha