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| I claim: 1. An encoder of one or more channels of input signals comprising signal samples, said ... |
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| Montgomery reduction apparatus |
| OF THE INVENTION A Montgomery reduction apparatus and method of the present invention aim at more ... |
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| Audio system for vehicular application |
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| Medium having photographically recorded digital audio bits |
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| Digital hearing aid |
| Therefore, it is an object of the present invention to provide a digital hearing aid which can ... |
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| Apparatus for creating 3D audio imaging over headphones using binaural synthesis |
| Accordingly, it is an object of the present invention to provide an apparatus for creating three-... |
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| System, apparatus, and method for improving speech quality in multi-party devices |
| A method, system, and apparatus are provided, such that cross talk terms may be removed from speech ... |
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| Speaker excursion control system |
| OF THE PREFERRED EMBODIMENT Referring initially to FIG. 1, there is shown a sound system which may ... |
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| Portable information terminal device with radio selective-calling receiver |
| In view of the foregoing, it is an object of the present invention to provide a portable ... |
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Integrated circuit for audio enhancement system
| Details |
Inventors: Katz, Joel; Kath, Miles;
Assignee: HDA Entertainment, Inc. (Timonium, MD)
Primary Examiner: Isen; Forester W.
Assistant Examiner:
Attorney, Agent or Firm: de Angeli; Michael
An integrated circuit for use as a building block in different embodiments of systems for enhancing audio performance by providing group delay to various frequency components of the signal. The integrated circuit includes four op amps and associated circuitry. Using external connections, the device can be configured as a two-channel stereo device, or can be cascaded for monaural applications. Two of the chips may be cascaded together for stereo applications. External capacitances and resistances are used to control the degree of group delay provided to the signal to realize desired audio enhancement. |
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DETAILED DESCRIPTION It is therefore an object of the invention to provide an improved system for enhancement of the aesthetic qualities of reproduced audio, particularly music.
It is a further object of the invention to provide an integrated circuit for use as a building block in audio enhancement processor devices whereby the same basic integrated circuit can be used in a monaural, cascaded monaural, stereo or cascaded stereo configuration at minimal cost and with minimal external components, such that audio enhancement devices can be made readily and economically available, and so that the same integrated circuit can be employed for sound enhancement in numerous different applications, including recording studios, broadcast studios, and home and mobile audio systems.
It is a further object of the invention to provide an integrated circuit for use in audio enhancement systems, wherein a group delay is applied to the audio signal to be enhanced, whereby the individual frequency components of the audio signal are delayed in substantially an inverse-square relationship to their frequency.
It has been found by the present inventors that the various approaches to enhancement of recorded audio material represented by the above prior art disclosures can be further improved.
More specifically, the present inventors have found that superior results may be obtained by mixing the individual frequency components of the input audio signal under appropriate processing conditions such that various sum and difference components are obtained.
Preferably, this is done in a system whereby the additional signals thus produced are added to the input signal with a group phase delay, such that the additional signals resulting from the sum and difference mixing are heard by the listener some little time after the input signal, that is, are delayed with respect to the portion of the input signal from which the sum and difference signals are derived.
More specifically, the group delay imparted to the audio signal should be substantially an inverse-square function of the frequency of the various components of the input signal
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Audio Signal Processing 
