 Automatically switched equalization circuit |
| In the present invention, when an electrical connector is inserted into the subwoofer output jack, ... |
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| Loudspeaker apparatus |
| It is the principal aim of the invention to provide a loudspeaker apparatus which overcomes the ... |
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| Stereo electroacoustic transducing |
| What is claimed is: 1. A stereo loudspeaker system for providing good stereo imaging over a wide ... |
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| Loudspeaker system |
| It is an object of the present invention to provide a loudspeaker system which increases the size ... |
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| Method of simulating a room and/or sound impression |
| OF THE PREFERRED EMBODIMENTS FIG. 1a of the drawing shows a possible method of determining the ... |
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| Acoustic display system and method for ultrasonic imaging |
| The invention provides an ultrasonic imaging system with a three-dimensional acoustic display. In ... |
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| Panel-form microphones |
| What is claimed is: 1. A panel-form microphone for operation in a predetermined frequency range, ... |
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| Audio system for a computer display |
| OF THE INVENTION Referring to the drawing there is shown an essentially rectangular screen S of an ... |
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| Apparatus and method for adjusting audio equipment in acoustic environments |
| The foregoing objects are achieved by this invention in which the signal in each channel of a ... |
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| Method for the authentication of data |
| It is an aim of the invention to increase the possibilities of the method of authentication so that ... |
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Method of transmitting an audio signal
| Details |
Inventors: Schroder, Ernst; Voessing, Walter;
Assignee: Deutsche Thomson-Brandt GmbH (Villingen-Schwenningen, DE)
Primary Examiner: Harkcom; Gary V.
Assistant Examiner: Knepper; David D.
Attorney, Agent or Firm: Spencer & Frank
A method of digital transmission of an audio signal, in which in order to save transmission and/or memory capacity, the digital signal is converted, before transmission, into signals representing the short-term spectrum of time sections of the digital signal and portions of this signal are processed on the basis of psycho-acoustic laws, with portions of this signal lying below given thresholds left unconsidered, with at least one first threshold being defined below which only amplitude values outside of psycho-acoustically differentiable frequency ranges are left unconsidered. |
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DETAILED DESCRIPTION What is claimed is: 1.
A method of transmitting an analog audio signal in digital form to be reconverted to analog form, comprising the steps of: converting an analog audio signal to a first digital signal; dividing the first digital signal in time segments; converting divided portions of the first digital signal in the respective time segments into respective second digital signals representing the respective short-term spectrums of the time segments; encoding the second digital signals for transmission while omitting from encoding portions of said second signals having signal levels which lie below given thresholds having values based on the psycho-acoustic law of masking, and such that the portions of the second signals having signal levels which are below the thresholds and are thus omitted, represent the frequency components of the short-term spectrum outside of at least one psycho-acoustically differentiable frequency range; and transmitting the encoded second signals.
2.
A method as in claim 1, wherein the at least one psycho-acoustically differentiable range includes the frequency range in the vicinity of the absolute maximum level of the short-term spectrum.
3.
A method as in claim 2, wherein all frequency components in the frequency range in the vicinity of the absolute maximum level of the short-term spectrum are encoded.
4.
A method as in claim 2, wherein frequency components which are in the frequency range in the vicinity of the absolute maximum level of the short-term spectrum, and which have levels below the threshold, are encoded.
5.
A method in claim 1, wherein the at least one psycho-acoustically differentiable range includes the frequency range in the vicinity of the absolute maximum level of the short-term spectrum.
6.
A method as in claim 5, wherein the entire frequency range of the short-term spectrum is divided into frequency groups which each include at least one spectral component and wherein the thresholds are defined individually for each group and separately related to the maximum level of the spectral components of the each group, and wherein the frequency range formed by the vicinity of the absolute maximum level of the short-term spectrum coincides with the frequency range taken up by the group which includes the absolute maximum level
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Audio Signal Processing 
