Abstract: A method and apparatus for removing or amplifying voice or other signals panned to the center of a stereo recording utilizes frequency domain techniques to calculate a frequency dependent gain factor based on the difference between the frequency domain spectra of the stereo channels.

Abstract: A receiver in an audio distribution system provides graceful degradation of audio quality as transmission quality decreases by dynamically adjusting the volume of audio output as a function of transmission quality. The receiver estimates the rate of transmission errors in a transmission link on which the audio signal is distributed by detecting errors in known information embedded in the audio signal. As the rate of transmission errors increases, the receiver increasingly attenuates the volume of the audio output. The receiver dynamically adjusts the volume relative to the rate of transmission errors applying a smoothing function to avoid disruptive rapid fluctuations in audio output volume.

Abstract: A circuit for processing broadcast signals that includes circuitry for receiving and processing broadcast signals which contain audio information and providing a first audio signal, and circuitry for controlling the amplitude of a received second audio signal in response to a first control signal, and providing a third audio signal wherein the circuit further comprises circuitry that receives the first audio signal and provides the second audio signal for automatically limiting the amplitude of the first audio signal in response to at least one reference signal.

Abstract: A method to denoise a stereo signal comprising a stereo sum signal and a stereo difference signal, performs a frequency selective stereo to mono blending based on the masking effect of the human auditory system. Therefore, a stereo signal noise reducer, comprising a first filter bank (1) to split the stereo difference signal (1−r) into a plurality of subbands, respective first multipliers (20, . . . , 2N) to weight each of the subbands of the stereo difference signal with a respective corresponding control signal (C0, . . . , CN), and a first adder (3) to sum all weighted subbands of the stereo difference signal (1−r) to build a frequency selective weighted stereo difference signal (diff), within which a number and width of the subbands obtained via the first filter bank (1) are choosen according to the properties of the human auditory system, further comprises a weighting factor determination unit which determines a respective control signal (C0, . . .

Abstract: In the coding and decoding of stereo audio spectral values both the intensity stereo process and prediction are used in order to achieve high data compression. If intensity stereo coding is active in one section of scale factor bands, the prediction for the right channel in that range is deactivated, whereby the results of the prediction are not used to form the coded stereo audio spectral values. To allow further adaptation of the prediction for the right channel, the predictor of the right channel is fed with stereo audio spectral values for the channel, which again are intensity stereo decoded.

Abstract: A transmitting system consisting of a control apparatus and a target apparatus connected mutually via an IEEE1394 bus wherein unitary data having an isochronous gap for transmission of audio main data and an asynchronous gap for transfer of command data are transmitted between the control apparatus and the target apparatus via the bus. The control apparatus includes a unit for sending an identifier to identify the target apparatus by the use of the asynchronous gap, and also a command to request transfer of a signal level from the target apparatus. The target apparatus includes a unit for receiving the identifier from the sending unit of the control apparatus via the IEEE1394 bus and also the command to request transfer of the signal level of the target apparatus; and a unit for sending an audio signal level in response to the signal-level transfer request command received by the receiving unit. In this system, an output level can be set in and read out from the target apparatus by the control apparatus.

Abstract: A method and system is disclosed for transmitting two related channels of signals through the air. A first channel of signals is modulated with a first carrier frequency, and a second channel of signals is modulated with a second carrier frequency. The modulated first channel of signals and the second channel of signals are then combined through a high isolation combiner. Thereafter, the combined signals are transmitted toward a receiver system. After receiving the transmitted signals, the first channel and the second channel of signals are regenerated in the receiver system by separating one from the other.

Abstract: A wireless transmitter/receiver circuit system having a transmitter circuit and a receiver circuit, that enable a wireless headphone or speaker system to automatically trace floating frequency upon receiving of a transmitting signal, so as to achieve a quality receiving. The transmitter circuit includes a pilot oscillator and a 32K˜1 MHz selector, that are controlled to encrypt transmitting signal, enabling transmitting signal to be accurately received by the receiver circuit. The receiver circuit has a concealed receiving antenna installed in a metal shell for direct coupling by air, a pilot select, a digital logic and a scan driver for automatically scanning signal transmitted from the transmitter circuit, enabling transmitted signal from the transmitter circuit to be accurately provided to the headphone or speaker system.

Abstract: A receiver/transmitter for use in an audio system having a reproducing device for providing reproduced audio signals and located in a home or office. The receiver/transmitter may be operable in a number of modes in which one of such modes enables reproduced audio signals to be transmitted over a broadcast frequency for reception by a wireless receiver tuned to the broadcast frequency and located in a different location of the home or office from that of the receiver/transmitter. Such wireless receiver may be a portable type radio receiver or a stationary type radio receiver. As a result, an operator may listen to a desired portion of a compact disc or tape or the like which is being reproduced by the reproducing device in one room or portion of the home or office while the operator is in a different room or portion of the home or office or while the operator is moving between rooms or portions of the home or office.

Abstract: A frequency modulation (FM) multiplex demodulation device is provided, in which the feeling of stereo is maintained excellent and the offensive noise to the ears can be reduced.

Abstract: An FM stereo signal demodulating apparatus includes a bandpass filter 1 for extracting a 19 Hz signal from an FM detected signal; a first phase shifter 21 for phase-shifting the 19 Hz signal by 90 degree; a first XOR 22 for taking an exclusive OR between an output from the first phase-shifter 21 and the 19 KHz signal; a second phase shifter 23 for phase-shifting an output signal from said XOR 21; a second XOR 24 for taking an exclusive OR between an output from the first XOR 22 and an output from the second phase shifter; an inverter 25 for inverting an output from said XOR 24; a third phase-shifter for phase-shifting an output signal from said inverter 25; a third XOR for taking an exclusive OR between an output from said third phase-shifter 26 and an output from said first XOR 22; a first multiplier 3 for multiplying an output from said first XOR 22 and said FM detected signal; a second multiplier 4 for multiplying an output from said third XOR 27 and said FM detected signal; a third multiplier 5 for multip

Abstract: A digital FM signal generator allows the generation of a modulated FM signal for broadcasting without the need for an analog modulator. The signal generator includes a digital signal processor which receives left and right signals from left and right signal channels and interpolates the signals to create a composite base band signal. The composite base band signal is then used by a numerically controlled oscillator to modulate a digital carrier signal. The result is a digital modulated FM RF signal which is then converted to an analog signal for broadcasting.

Abstract: An integrated circuit for decoding an analog audio signal includes a tuner that receives the analog audio signal and provides a sound intercarrier frequency signal. A digital demodulator receives and digitizes the sound intercarrier frequency signal to provide a digitized sound intercarrier frequency signal, and digitally demodulates the digitized sound intercarrier frequency signal to provide a digitized multichannel television sound (MTS) demodulated signal. A digital broadcast television system committee (BTSC) compatible decoder receives and decodes the digitized multichannel television sound (MTS) demodulated signal, and provides a summed (L+R) audio output signal and a difference (L−R) audio output signal.

Abstract: The present invention includes a digital stereo modulator having a digital left channel input and a digital right channel input into a Digital BTSC Stereo Generator that contains a Sine Table. The Digital BTSC Stereo Generator generates and outputs the following signals: 2*FH, compressed BTSC L−R, preemphasized BTSC L+R, and FH. A digital multiplier amplitude modulates the 2*FH carrier with the compressed BTSC L−R output, and the resultant signal is a Stereo Subchannel AM-DSB-SC BTSC Compressed L−R, which is then summed together with the preemphasized BTSC L+R, and FH by a digital summer. The output of the digital summer is the composite BTSC output without SAP or Professional channels. The Digital BTSC Stereo Generator transforms left and right inputs into the outputs described above by utilizing clock inputs 3*FH and 12*FH. A digital PLL phase locks 3*FH and 12*FH clocks to a Horizontal Synch (FH) reference, for input to the Digital BTSC Stereo Generator.

Abstract: An apparatus for receiving broadcasting signals, which includes a tuner for receiving a digital audio broadcasting signal, a data demodulating portion for obtaining time interleaved information data based on the digital audio broadcasting signal received by the tuner, a time de-interleaving portion for causing the time interleaved information data to be subjected to a time de-interleaving arrangement, an audio signal reproducing portion for obtaining a reproduced audio signal based on time de-interleaved information data obtained from said time de-interleaving portion, a RAM for storing unit data constituting the time interleaved information data therein and reading stored unit data therefrom when the time interleaved information data are subjected to the time de-interleaving arrangement, and a memory control portion for controlling storage of the unit data in the RAM and for reading the stored unit data from the RAM and operative to utilize a part of the RAM which is not used for storing and reading the unit

Abstract: A headphone containing right/left-channel acoustic units capable of converting an analog audio signal into acoustic sounds. An input jack to which is supplied a digital audio signal derived from a digital audio appliance is provided within the headphone. A D/A converter for D/A-converting the digital audio signal supplied to the input jack into an analog audio signal, and an amplifier for amplifying the analog audio signal derived from the D/A converter to supply the amplified analog audio signal to the right/left-channel acoustic units, are provided in this headphone.

Abstract: The present invention is a method and apparatus for providing stereo audio signals is disclosed. The circuit for providing stereo audio signals comprises an interface circuit coupled to receive an audio signal. The interface circuit has an analog-to-digital converter for digitizing the audio signal to provide a first audio input signal and a second audio input signal. A first processing circuit coupled to the interface circuit is configured to generate a first audio output signal based on the first audio input signal. A second processing circuit coupled to the interface circuit is configured to generate a second audio output signal based on the second audio input signal. The circuit further comprises a processor coupled to the interface circuit and a memory for storing instruction sequences.

Abstract: An audio encoding transmission system is provided for a transmitting station which performs data transmission with respect to a receiving station through a network. The transmitting station contains a scalable encoder which performs an encoding process on audio signals input thereto in response to bit rate information representing a bit rate which is variable in response to a condition of the network. Results of the encoding process are partitioned into outline data, having a low bit rate, and detail data. Herein, the outline data correspond to low-frequency components of the audio signals while the detail data correspond to high-frequency components of the audio signals, for example. A bit stream is constructed using the outline data and detail data as well as additional information such as a header and a boundary identifier which are created on the basis of the audio signals and bit rate information. Thus, the transmitting station transmits the bit stream to the receiving station via the network.

Abstract: A controller for a powered loudspeaker for use in a computer system including a bus monitor configured to monitor a bus for predetermined activity and a power management control unit coupled to the bus monitor. The controller is configured to turn off power supplied to the powered loudspeaker responsive to an absence of predetermined activity on said bus. After a predetermined interval, or upon detection of restoration of activity, the power is turned back on.

Abstract: A receiving apparatus for receiving digital broadcasting of a first frequency band and frequency band has a local oscillation circuit for generating a first local oscillation signal, and a frequency conversion circuit for frequency-converting the first local oscillation signal to generate a second local oscillation signal. The received signal of the first frequency band is up-converted to a first intermediate frequency signal using one of the of first and second local oscillation signals, and the received signal of the frequency band is down-converted to the first intermediate frequency signal using the other of the first and second local oscillation signals.

Abstract: The present invention relates to a process and a device for the wireless transmission of a signal S.sub.1 between a transmitter and at least one receiver.According to the invention, at the sending end:a first carrier S.sub.2, of frequency F.sub.2, situated in the VHF (Very High Frequency) range, is frequency-modulated by the signal S.sub.1 to be transmitted, and thena second carrier S.sub.3 of frequency F.sub.3, situated in the SHF (Super High Frequency) frequency range, is amplitude-modulated by a modulating signal S.sub.2m. resulting from the frequency modulation of the carrier S.sub.2 so as to transmit an amplitude-modulated signal S.sub.3m to the receiver,and at the receiving end:amplitude demodulation of the signal S.sub.3m is performed so as to recover the signal S.sub.2m, and thenfrequency demodulation of the signal S.sub.2m is performed so as to recover the signal S.sub.1.

Abstract: Jointly processed stereophonic audio signal properties are identified using a stereophonic signal as reference signal and creating a signal for testing by processing the stereophonic signal, e.g. by coding and subsequently decoding it. Both signals are transformed into the frequency domain to create representative spectral data for the respective subbands. Correlation coefficients are determined for each subband both of the reference signal and also of the signal for testing on the basis of the spectral data of the channels of the reference signal or of the signal for testing. From the comparison of the correlation coefficients belonging to the same subband, jointly processed stereophonic audio signals are detected if at least one of the correlation coefficients of the signal for testing greatly exceeds the correlation coefficient of the reference signal for the same subband.

Abstract: A multiplex transmission device for multiple-channel signals, in particular multiple-channel audio signals, has a plurality of input channels, each of which receives an input signal, a multiplexer, the input channels being connected with the inputs of the multiplexer, and with an output channel which is connected to the output of the multiplexer for sending an output signal which is multiplexed from the input signals. A control element is connected in each input channel for controlling the amplitude of the respective input signal and a regulating device is provided for controlling the control elements. A special feature of the device consists in that the regulating device uses the output signal of the multiplexer as a regulating variable.

Abstract: A powered microphone for use with a personal computer comprising a Universal Serial Bus interface for coupling the powered microphone to a Universal Serial Bus. A circuit coupled to the Universal Serial Bus interface is configured to integrate a plurality of data streams, including clock data, digital audio data, and control data into Universal Serial Bus compatible data. A gain controller is coupled to provide control signals to a power supply and amplifier; and an audio data circuit is coupled to receive clock data and analog audio data. The audio data circuit includes an analog-to-digital converter for converting the analog audio data to a digital audio signal, and the audio data circuit is further configured to receive an audio control signal from the gain controller.

Abstract: A multi-channel signal compressor for compressing digital sound signals in the respective channels of a multi-channel sound system. The apparatus comprises a first-stage compression system and a second-stage compression system. In the first-stage compression system, a coupling circuit performs coupling between the digital sound signals of at least two of the channels to generate coupling-processed signals, one for each of the channels. A compressor circuit receives the coupling-processed signals from the coupling circuit and frequency divides each coupling-processed signal into frequency range signals in respective frequency ranges, and compresses the frequency range signals obtained by dividing each coupling-processed signal to generate a first-stage compressed signal.

Abstract: A storytelling system in which a base unit broadcasts some blocks of audio data stored therein, and transmits other blocks of audio data stored therein to remote units for remote broadcast. Transmission to the remote units may be as radio signals, as ultrasound signals, as infrared signals, or as electrical impulses transmitted along wires. The blocks of data include identification codes to indicate which units are to broadcast them. The remote units have unique identifying features and are covered by matching dolls representing characters of the story. Each remote unit broadcasts the audio data appropriate to its own doll.

Abstract: The broadcast mode of the different ones set by the international standards for digital audio broadcasting (DAB) according to a coded orthogonal frequency division multiplexing scheme (COEFDM) may be automatically detected in a receiver through a detection routine. Many of the calculation modules required by the automatic mode detection system of the invention are already present in a receiver and can be exploited for performing the digital signal processing that leads to an automatic recognition of the broadcast mode of the station on which the receiver is tuned.

Abstract: When transmitting a sigma-delta modulated signal produced from plural channel signals through a sigma-delta modulator, the main channel is made to have a different sampling frequency from the sub channel, for enhancing transmission efficiency.

Abstract: A method and apparatus for transmitting digital sound is disclosed. The method contemplates transmitting a digital radio signal (such as an FM band signal) over a plurality of sub-channels subject to some constraints on the digital signal power. A control sub-channel, sometimes referred to as an auxiliary overhead channel is used to transmit control information which is interpreted by the receiver to identify the location and potentially the mode of the digital signals.

Abstract: There is provided a novel powered loudspeaker implemented to be compatible with the USB specification. The powered speaker includes a speaker driven by a power amplifier coupled to a power supply. Both the amplifier and the power supply, in turn, are coupled to a USB controller. The controller is configured to provide USB functionality and compatibility. In addition, provides a phase locked loop (PLL) for recovering a timer clock from the received data stream. The present invention further includes a function whereby the absence of data on the relevant channel is detected and the output to the speakers is muted in response thereto. A further circuit is provided that controls when the output to the speaker is turned on such that no clicks or pops occur at power-up or when the device or bus is not stable. In addition, tone control, including base and treble filters, volume control, and balance between left and right outputs (in a stereo version) are provided.

Abstract: A transmitter for transmitting at least a first and a second main signal component is disclosed, having at least two input terminals for receiving the at least two input signals. The transmitter comprises multiplexer means for multiplexing the at least two input signals to a first input of matrixing means, and to an input of first bitrate reducing means. The first bitrate reducing means is for carrying out a data reduction step on the signal applied to its input and to supply a data reduced version to an output. Expansion means are present, having an input coupled to the first bitrate reducing means, for carrying out a data expansion on the data information applied to its input, so as to obtain a replica of the signal applied to the input of the bitrate reducing means at an output. Said output is coupled to a second input of the matrixing means. An output of the matrixing means is coupled to signal combination means via second bitrate reducing means.

Abstract: Disclosed is a partitioning procedure for designing MPEG decoders, AC-3 decoders, and decoders for other audio/video standards. The procedure provides that some specified decoding functionality be implemented exclusively in the form of hardware and certain other specified decoding functionality be provided exclusively as firmware or software. A video decoder designed according to this procedure includes the following elements: (a) firmware or software for implementing, in conjunction with a CPU, video header processing functions; and (b) hardware for implementing preparsing assist, macroblock reconstruction, and video display control functions. An audio decoder designed according to this procedure includes the following elements: (a) firmware or software for implementing, in conjunction with a CPU, decoding fields containing parameters for processing the audio data; and (b) hardware for implementing matrixing and windowing functions on the audio data.

Abstract: A method for reducing data during the transmission and/or storage of the digital signals of several dependent channels is described in which the dependence of the signals in the channels, e.g. in a left and a right stereo channel, can be used for an additional data reduction. Instead of known methods such as middle/side encoding or the intensity stereo process that lead to perceptible interference in the case of an unfavourable signal composition, the method according to the invention avoids such interference, in that a common encoding of the channels only takes place if there is an adequate spectral similarity of the signals in the two channels. An additional data reduction can be achieved in that in those frequency ranges where the spectral energy of a channel does not exceed a predeterminable fraction of the total spectral energy, the associated spectral values are set at zero.

Abstract: In the case of coding a plurality of signals which are not independent of e another, a selection of the suitable type of coding is made as a function of a similarity measure.According to one aspect of the invention, the similarity measure is determined by firstly coding one of the signals according to the intensity-stereo method and then decoding it in order to create a signal affected by coding error, whereupon the latter signal and the associated non-coded signal are transformed into the frequency domain. In the frequency domain, a selection or evaluation of the actually audible spectral components, as well as of the signal affected by coding error and of the associated signal not affected by coding error, is undertaken using a listening threshold which is determined by a psycho-acoustic calculation. Intensity-stereo coding is undertaken in the case of a high similarity measure, whereas otherwise a separate coding of the channels is performed.

Abstract: A digital audio encoder that enables the digital signal processing of a stereo audio signal and multiplexed voice data by extending a two-channel digital audio system of comparatively simple construction. Stereo audio data and multiplexed voice data are sampled and scaled for adjusting the range of the signals. Thereafter, a window is applied to the data. With the window, adjacent blocks are overlapped in order to eliminate noise between the blocks. MDCT and MDST functions are performed using the same size window for extracting and normalizing MDCT and MDST coefficients which respectively indicate an exponent and a mantissa. The mantissa consists of fixed bit data and variable bit data. In order to determine the fixed bit data, fixed bit data are allocated on a sub-band basis. In order to determine the variable bit data, each of the remaining bits are allocated on a sub-band basis from the lowest frequency band. Thereafter, quantization is performed.

Abstract: A five-channel perceptual audio compression system which encodes five matrixed channels switches among a fourteen encoding modes each utilizing a respective different set of matrixed channels. Six of the modes are for encoding the three front channels and eight of the modes are for encoding the two back channels. The rate of perceptual encoding the matrixed channels is controlled by adjusting individual noise thresholds as a function of a global masking threshold.

Abstract: A process for reducing data in the transmission and/or storage of digital signals of several interdependent channels is described.As the signals from the channels are not independent of one another, an additional data quantity reduction is possible during transmission.In known processes for the coding of signals from two stereo channels, in the case of an unfavorable signal composition interference can be caused by the coding process and cannot be concealed by the signal actually present in the channel and consequently reduce listening enjoyment.In the process according to the invention and with the aid of the spectral values of corresponding blocks of several channels, there is a balancing of the necessary data rate for a separate coding of the two channels and for a joint coding. There is a joint coding of the channels for as long as the data rate for the joint coding does not exceed by a predeterminable value the data rate for the separate coding of the particular channel.

Abstract: The FM stereo broadcasting apparatus has a sampling frequency converter for receiving a digital input signal having an L (left audio)-signal and an R (right audio)-signal and for converting the digital input signal so that its sampling frequency is equal to either a frequency of a subcarrier of a composite audio signal or a first sampling frequency of a first sampling signal for the operation of a composite audio signal generator, a sampling signal generator for generating the first sampling signal for the operation of the composite audio signal generator having the first sampling frequency which is equal to 2.sup.

Abstract: An analog spread spectrum wireless speaker system for use in consumer audio applications for providing reliable and high fidelity stereo sound. The system includes a transmitter that accommodates any analog input from a variety of audio devices such as compact disk players, cassette players, AM/FM tuners and transmits this information in the 2.4-2.4835 GHz band to a receiver at a remote location. The receiver is capable of reproducing the audio signal with good frequency and signal-to-noise performance.

Abstract: A small-sized audio signal reproducing apparatus for hearing reproduced audio signals with the aid of a headphone is disclosed. Digitized and compression encoded audio signals, stored in a semiconductor memory, are read out so as to undergo a decoding operation, which is an inverse operation to compression encoding, to reproduce the audio signals, and the reproduced signals are heard by the headphone. The apparatus may be significantly reduced in size and weight, as compared to the apparatus in which a tape or a disk is used as the recording medium.

Abstract: In order to require only a relatively small increase in the data rate when the number of channels of multi-channel digitalized and bit-rate reduced audio signals is increased, the psychoacoustic concealment or masking by at least part of the remaining audio channels or the redundancy of individual audio channels is taken advantage of in each individual audio channel when reducing the bit rate of audio signals having more than two audio channels. Only those parts of the concerned audio channel are transmitted or stored which are not concealed by the audio signals of other audio channels or which are contained in the audio channels for stereophonic reproduction with all types of reproduction available for selection. In addition, the used parts are transmitted or stored with a resolution only big enough for the totality of all audio channels to keep concealed the quantization noise generated during quantization in all types of reproduction available for selection.

Abstract: Techniques for encoding audio signals are disclosed wherein a left channel signal masking threshold and a right channel signal masking threshold may be advantageously adjusted. A given time block of a stereo audio signal comprises a left channel signal and a right channel signal, each of which are represented in a frequency domain by a first plurality of frequency partitions and a second plurality of frequency partitions, respectively. For a frequency partition from the first plurality of frequency partitions and a corresponding frequency partition from the second plurality of frequency partitions, a scheme first calculates a set of masking thresholds comprising the left channel masking threshold and the right channel masking threshold. Next, based upon the set of masking thresholds, the scheme calculates an adjusted left channel masking threshold and an adjusted right channel masking threshold.

Abstract: System for digital transmission of left and right stereo signals and a center signal through left and right stereo channels and an auxiliary channel, respectively.

Abstract: An apparatus and method receive and process information, and adapt the operational characteristics of the processing in response to material included in the received information. More particularly, the apparatus and method embody a software-controlled process which adapts or modifies the software in response to the received information. One embodiment is described in connection with a motion picture film which carries a conventional analog SVA soundtrack and a digital soundtrack with a digital representation of software required to properly process the digital soundtrack.

Abstract: Reproduction accuracy of, for example a digital stereo audio signal, is improved by transmitting sample data as sub-signals such as frequency subband signals. In one or more subbands, corresponding components such as left and right stereo channels are combined so that only one composite signal is transmitted per subband. An indicator signal is transmitted, indicating which subbands are combined. Scale factor signals for all subbands, and for the relative intensity of the respective subband signals which were combined, may also be transmitted. In the receiver a subband signal is derived for each channel from the composite signal, before synthesis of the full channel signals which will be reproduced.

Abstract: A circuit for multiplexing three or more audio band electrical signals into two audio band electrical signals which can be provided to a stereo input and a circuit and computer method for demultiplexing the signals. In particular, six signals from the six strings of a guitar are multiplexed for stereo audio analog input to a sound card in a personal computer where the signals are digitized and then, using software running on the computer, demultiplexed into six signals from which the frequencies above 4.5 kHz have been lost.

Abstract: A sound collecting system and a sound reproducing apparatus by means of which an actual audio image can be reproduced. The sound collecting system includes a plurality of microphones for producing sound signals and a plurality of position detecting apparatus for detecting locations of the microphones and/or positions of sound sources to produce position signals. The sound signals and the position signals are multiplexed by a plurality of multiplexers, and the multiplexed signals are stored into respective audio channels or different channels by a signal recording apparatus. The multiplexing may be performed by a frequency multiplexing method, a time division multiplexing method or the like. Since also position information is stored into corresponding audio channels together with acoustic sound signals, at the reproducing stage, reproduction is possible taking the positions into consideration and an actual audio image can be produced.

Abstract: A system is provided which transmits either analog or digital data signals over the air. The system includes a transmitter and a receiver. The transmitter and receiver are arranged to transmit signals using a carrier signal having a high frequency such as in the range of 902-928 MHz. The transmitter and receiver are configured to provide for the transmission of two channels of stereophonic signals while maintaining high signal-to-noise ratios, good frequency response, and low distortion. To provide for the proper transmission of signals between transmitter 10 and receiver 12, these devices include oscillating circuits having ceramic resonators which provide a base frequency which is readily modulated to facilitate proper transmission of either analog or digital signals between the transmitter and receiver.

Abstract: A radio information broadcasting and receiving system consisting of three major parts: an FM transmitter station with subcarrier multiplexing capability, an FM receiver apparatus with subcarrier demodulation capability, and a computer connected in combination with the receiver apparatus. The FM transmitter station includes sources of main programming signals first digital data signals and second digital data signals. The first and second digital data signals are modulated by subcarrier 1 and subcarrier 2 frequencies respectively and are mixed with the main program signal and then transmitted. The transmitted signals are received by a receiver apparatus including an FM receiver circuit and an FM demodulator circuit for receiving the broadcast signal and demodulating it. The demodulated main program audio frequency signal is applied through a filter/deemphasis circuit and amplifier to speaker to provide an audio output.

Abstract: A system for broadcasting audio music and broadcasting lyrics for display and highlighting substantially simultaneously with the occurrence of the lyrics in the accompanying audio music is provided. The system includes a an audio music source that provides a data output and a an analog audio signal output. A computer receives the data output by the music source and generates lyric text data and lyric timing commands. A subcarrier generator generates a subcarrier signal carrying the lyric text data and lyric timing commands. An FM transmitter broadcasts a composite signal that combines the analog output of the music source with the subcarrier signal. A lyric display unit receives the composite signal, separates and decodes the subcarrier signal and displays and highlights lyrics according to the lyric text data and lyric timing commands decoded from the subcarrier signal.