Abstract: A method for transcoding a bit stream encoded according to a mixed-excitation linear prediction (MELP) standard to a bit stream encoded according to a linear predictive coding (LPC) standard, including: decoding a bit stream into a first set of vocoder parameters compatible with the MELP standard; transforming the first set of vocoder parameters into a second set of vocoder parameters compatible with the LPC standard without converting the first set of vocoder parameters to an analog or digital waveform representation; and encoding the second set of vocoder parameters into a bit stream compatible with the LPC vocoder standard.

Abstract: A method for transcoding a bit stream encoded according to a linear predictive coding (LPC) standard to a bit stream encoded according to a mixed-excitation linear prediction (MELP) standard, including: decoding a bit stream into a first set of vocoder parameters compatible with the LPC standard; transforming the first set of vocoder parameters into a second set of vocoder parameters compatible with the MELP standard without converting the first set of vocoder parameters to an analog or digital waveform representation; and encoding the second set of vocoder parameters into a bit stream compatible with the MELP vocoder standard.

Abstract: A method for enhancing speech prediction coefficient signals, including: a) receiving a set of prediction coefficient signals; b) calculating a set of amplitude spectrum coefficient signals based on the prediction coefficient signals; c) calculating a set of enhancement coefficient signals based on the amplitude spectrum coefficient signals; d) calculating a set of enhanced autocorrelation coefficient signals based on the enhancement coefficient signals; e) converting at least some of the enhanced autocorrelation coefficient signals into reflection coefficient signals; f) testing the range of values of the reflection coefficient signals; and g) converting at least some of the tested reflection coefficient signals into prediction coefficient signals.

Abstract: The system and method of the present invention comprises a compressed domain conference bridge. The method includes maintaining full intelligibility for all users even when there are multiple simultaneous talkers. The bridge also allows a user to hear a plurality of talkers over a single channel.

Abstract: The system and method of the present invention comprises a compressed domain voice activity detector that detects the presence or absence of voice activity in a digital input signal. The method includes converting a digital input signal into parametric data. The parametric data is subsequently analyzed, and then compared against a background noise threshold to determine if voice activity is present.

Abstract: The system and method of the present invention comprises a compressed domain universal transcoder that transcodes a bit stream representing frames of data encoded according to a first compression standard (TDVC coding standard) to a bit stream representing frames of data according to a second compression standard (MELP coding standard). The method includes decoding a bit stream into a first set of parameters compatible with a first compression standard. Next, the first set of parameters are transformed into a second set of parameters compatible with a second compression standard without converting the first set of parameters to an analog or digital waveform representation. Lastly, the second set of parameters are encoded into a bit stream compatible with the second compression standard.

Abstract: An improvement in an apparatus used to retain a plastic guide that guides the post of a vehicle head restraint during vertical adjustment. The improved head restraint support tube formed from a flat sheet having two interlocking sides. The sheet formed into a tubular body that retains a plastic guide. The plastic guide used to guide the head restraint post within the hollow tube. The tubular body further having a necked down region with a smaller inner diameter when compared to the remainder of the tube to improve its retaining capability. Additionally, the improved head restraint support tube has a series of lances located at one or both ends to further retain the plastic guide and reduce lateral movement.

Abstract: The system and method of the present invention comprises a compressed domain universal transcoder that transcodes a bit stream representing frames of data encoded according to an LPC coding standard to a bit stream representing frames of data according to a MELP coding standard. The method includes decoding a bit stream into a first set of parameters compatible with the LPC coding standard. Next, the LPC set of parameters are transformed into a MELP set of parameters compatible with the MELP coding standard without converting the LPC set of parameters to an analog or digital waveform representation. Lastly, the MELP set of parameters are encoded into a bit stream compatible with the MELP coding standard.

Abstract: The present invention comprises a system and method for correlation domain formant enhancement. The method includes attenuating an output speech signal in areas of low spectral amplitude. The attenuated signals are subsequently analyzed, and then converted to a format suitable for transmission.

Abstract: The system and method of the present invention comprises a compressed domain universal transcoder that transcodes a bit stream representing frames of data encoded according to a first compression standard (MELP coding standard) to a bit stream representing frames of data according to a second compression standard (TDVC coding standard). The method includes decoding a bit stream into a first set of parameters compatible with a first compression standard. Next, the first set of parameters are transformed into a second set of parameters compatible with a second compression standard without converting the first set of parameters to an analog or digital waveform representation. Lastly, the second set of parameters are encoded into a bit stream compatible with the second compression standard.

Abstract: The system and method of the present invention comprises a hybrid dual/single talker speech synthesizer that produces a digital audio stream. The method includes decoding a compressed bit stream that contains encoded parameters. The encoded parameters describe either a single talker's voice input or encoded parameters describing two simultaneous talker's voice inputs. The dual synthesizer is able to decode such dual talker bit streams and handle transitions from dual talker to single talker modes and vice versa without introducing objectionable artifacts in the output audio.

Abstract: The system and method of the present invention comprises a compressed domain voice activity detector that detects the presence or absence of voice activity in a digital input signal. The method includes converting a digital input signal into parametric data. The parametric data is subsequently analyzed, and then compared against a background noise threshold to determine if voice activity is present.

Abstract: The system and method of the present invention comprises a compressed domain conference bridge. The method includes maintaining full intelligibility for all users even when there are multiple simultaneous talkers. The bridge also allows a user to hear a plurality of talkers over a single channel.

Abstract: The system and method of the present invention comprises an apparatus and method for ultra-low rate encoding of sound parameters. The method includes encoding a plurality of frames of pitch and gain information based on a predetermined quantizer table. After the pitch and gain frames are encoded, the frames are analyzed to determine which frames have the lowest distortion value. The frames with the lowest distortion value are subsequently transmitted.

Abstract: The system and method of the present invention comprises a compressed domain universal transcoder that transcodes a bit stream representing frames of data encoded according to a first compression standard (MELP coding standard) to a bit stream representing frames of data according to a second compression standard (LPC coding standard). The method includes decoding a bit stream into a first set of parameters compatible with a first compression standard. Next, the first set of parameters are transformed into a second set of parameters compatible with a second compression standard without converting the first set of parameters to an analog or digital waveform representation. Lastly, the second set of parameters are encoded into a bit stream compatible with the second compression standard.

Abstract: An improvement in an apparatus used to retain a plastic guide that guides the post of a vehicle head restraint during vertical adjustment. The improved head restraint support tube formed from a flat sheet having two interlocking sides. The sheet formed into a tubular body that retains a plastic guide. The plastic guide used to guide the head restraint post within the hollow tube. The tubular body further having a necked down region with a smaller inner diameter when compared to the remainder of the tube to improve its retaining capability. Additionally, the improved head restraint support tube has a series of lances located at one or both ends to further retain the plastic guide and reduce lateral movement.

Abstract: The system and method of the present invention comprises a compressed domain universal transcoder that transcodes a bit stream representing frames of data encoded according to a first compression standard (TDVC coding standard) to a bit stream representing frames of data according to a second compression standard (LPC coding standard). The method includes decoding a bit stream into a first set of parameters compatible with a first compression standard. Next, the first set of parameters are transformed into a second set of parameters compatible with a second compression standard without converting the first set of parameters to an analog or digital waveform representation. Lastly, the second set of parameters are encoded into a bit stream compatible with the second compression standard.

Abstract: The system and method of the present invention comprises a compressed domain universal transcoder that transcodes a bit stream representing frames of data encoded according to a first compression standard (LPC coding standard) to a bit stream representing frames of data according to a second compression standard (TDVC coding standard). The method includes decoding a bit stream into a first set of parameters compatible with a first compression standard. Next, the first set of parameters are transformed into a second set of parameters compatible with a second compression standard without converting the first set of parameters to an analog or digital waveform representation. Lastly, the second set of parameters are encoded into a bit stream compatible with the second compression standard.

Abstract: The present invention comprises a system and method for frequency domain formant enhancement. The method includes attenuating an output speech signal in areas of low spectral amplitude. The attenuated signals are subsequently analyzed, and then converted to a format suitable for transmission.

Abstract: The system and method of the present invention comprises a compressed domain universal transcoder that transcodes a bit stream representing frames of data encoded according to a first compression standard to a bit stream representing frames of data according to a second compression standard. The method includes decoding a bit stream into a first set of parameters compatible with a first compression standard. Next, the first set of parameters are transformed into a second set of parameters compatible with a second compression standard without converting the first set of parameters to an analog or digital waveform representation. Lastly, the second set of parameters are encoded into a bit stream compatible with the second compression standard.