Abstract: An audio signal processing apparatus including a plurality of jack units each of which has at least an audio signal contact piece and a control signal contact piece. A control circuit judges a kind of an audio appliance connected to each of the plurality of jack units based on a control signal obtained at the control signal contact piece, and when a function change-over command to select any one of the audio appliances is supplied, a function selecting circuit selects one of the jack units to which the audio appliance is connected. An audio appliance can be connected to any of the plurality of jack units.

Abstract: An audio system has multiple amplifiers, each with power supply inputs and audio inputs and outputs, for driving audio speakers according to a selected one of at least two modes of operation in which a selection of the audio speakers and/or a required power output of the audio speakers differ between the modes. The invention is operable, for example, to an entertainment system that has internal and external speakers and associated amplifiers for switching between stereo and surround sound modes. At least two distinct power supply voltage sources are provided for the amplifiers, and a switching element operates upon switching between the modes to couple one or another of the distinct power supply voltage sources to the power supply inputs of respective ones of the at least two amplifiers. This the total audio output of the system from increasing, for example, when switching from two stereo outputs to five surround sound outputs.

Abstract: A speech processor uses at least two speech processing features to enhance the quality of speech signals received by a user during a telephone call. The speech processing features are applied to the speech signals. However, the user only hears speech signals affected by one speech processing feature until both features have fully converged or ramped-up, and the two features are no longer interfering with each other. At that point, a “flash-cut” of the second speech processing feature is activated. The flash-cut instantaneously switches to speech signals affected by both features. This quick transition makes the speech processing features more noticeable to the user, and the user is not subjected to the period where the features interfere. Further, an optional audio indicator is generated before implementing the flash-cut, so the user is alerted to the flash-cut, and the speech processing features are even more noticeable.

Abstract: A microphone assembly includes a main plug unit, a voice-activated microphone unit, a throat-vibration-activated microphone unit, and a control circuit coupled to the main plug unit, the voice-activated microphone unit and the throat-vibration-activated microphone unit. The control circuit is operable between a first state, wherein the main plug unit is coupled to the voice-activated microphone unit and is disconnected from the throat-vibration-activated microphone unit, and a second state, wherein the main plug unit is disconnected from the voice-activated microphone unit and is coupled to the throat-vibration-activated microphone unit.

Abstract: A technique for controlling power of an audio processor in a monitor, which processes an audio signal from a computer system and outputs the processed audio signal to a speaker, in which an audio processor power control circuit includes: a power supply circuit for supplying operating power to the audio processor; a microcomputer for controlling an operating mode of the monitor according to an operating mode of the computer system and for adjusting an output volume of the audio processor, and a power switching device, operated under the control of the microcomputer, to supply the operating power from the power supply circuit to the audio processor upon the operating mode of the monitor being in a normal mode or a standby mode and to block the operating power from the power supply circuit to the audio processor upon the operating mode of the monitor being in a suspend mode or a power off mode.

Abstract: Circuitry for ramping a voltage across a load 506 includes a charging circuit 500 for charging a capacitor 501 to generate a ramp-up wave form. Circuitry 511 selectively decouples a first driver 510 from load 506 during a ramping up mode and couples first driver 510 to load 506 during a normal operating mode. Ramp up driver 507a is selectively coupled to the load 506 during the ramp-up mode for ramping up the voltage across load 506 in response to the ramp-up wave form generated by charging circuitry 500. A discharge circuit 503d, 514a,b discharges capacitor 501 to generate a power-down wave form. Circuitry 511 selectively decouples a first driver 501 from output load 506 during the ramping down of the voltage across output load 506. A ramp-down driver 507b selectively ramps-down the voltage across output load 506 in response to the ramp-down wave form generated by discharge circuitry 503d, 514a,b.

Abstract: A deep bass sound booster device comprises a high-pass filter to which an input sound signal is fed and which permits only a frequency component higher than a predetermined frequency to pass through so as to output a resulting signal, a bass booster to which the input sound signal is fed and which amplifies only a frequency component lower than the predetermined frequency and attenuates another frequency component so as to output a resulting signal, a switch to which the signal output from the bass booster is fed at one end and which, when turned on, outputs that signal at another end, and an adder to which the signal output from the high-pass filter is fed and to which the signal output from the switch is fed, the adder adding together those two signals and outputting a resulting signal.

Abstract: An acoustic conditioning apparatus. The mechanism includes an attenuator to limit excessive noise levels. The attenuator includes a circuit for compressing an output sound pressure level below a desired level, such as 90 dBA over an eight-hour period. The mechanism also includes an amplifier for conditioning ambient sound level in accordance with the normal needs of a hearing impaired person using the conditioning apparatus. Additionally included is a switch in an electrical circuit to enable selection of attenuation of excessive noise levels or normal amplification. The switch can be controlled either manually by means of a toggle on a housing enclosing the various components, or automatically in response to the sensed noise level.

Abstract: A computer system having automatic speaker detection circuitry is disclosed. The typical computer system includes a central processing unit, a data input device, and a sound card. Further, there is an audio amplifier, as well as an automatic detection and selection circuit that may be within the sound card or the audio amplifier or just part of the computer system as a whole. This automatic detection selection device is able to determine an impedance load of an output device attached to the computer system, namely, a speaker system, and is able to disable the audio amplifier within the computer system upon determining the impedance load and matching that impedance load against a selected value indicating that no amplification of the signal is required for the output device. Further, an audio sound equalizer is part of the system and can be bypassed in the same manner that the audio amplifier is, namely, that particular impedance load is measured indicating that no equalization is necessary.

Abstract: A mute apparatus comprises a plurality of mute switches 7 each operative to assume two operation states consisting of a mute-on state and a mute-off state; a mute executing switch 6 operative to assume two executing states consisting of a mute-on state and a mute-off state; mute switch control data generating means 3 for generating mute switch control data elements indicative of the operation states of the respective mute switches 7; mute switch control data determining means 4 for determining whether a mute executing switch 6 is to assume the mute-on or mute-off state on the basis of the mute switch control data elements; and mute switch means 5 for having the mute executing switch 6 selectively assume the mute-on and mute-off states on the basis of the mute-on or mute-off state determined by the mute switch control data determining means 4, thereby making it possible for the single mute switch means 5 to determine the execution state of the mute executing switch 6 to mute or unmute an audio signal inputted

Abstract: A recording/reproducing mixer comprises a recording/reproducing device that records and/or reproduces a plurality of audio signals in/from a plurality of tracks, a track selector that selects a track of said recording/reproducing device, a reader that reads audio signals of the selected track of said recording/reproducing device, a mixing device that mixes the read audio signals, a designator that designates a listening mode, and an output controller that outputs the read audio signals bypassing said mixing device when the listening mode is designated, and outputs the read audio signals via said mixing device when the listening mode is not designated.

Abstract: A stereophonic sound processing system for localizing a sound image at desired locations using devices including a headphone and a speaker, includes a processing unit for generating stereophonic sound on the basis of an input signal. The processing unit includes: a plurality of stereophonic filter units each including an FIR filter for processing an input signal; a selecting unit for selecting one of the plurality of stereophonic filter units in accordance with a desired factor; wherein the processing unit controls the selected stereophonic filter unit so as to generate stereophonic sound on the basis of a processed result supplied by the selected stereophonic filter unit.

Abstract: A microphone construction for use in a hearing aid includes a housing with first and second acoustic passages in communication with a microphone retaining chamber and acoustic openings in an exterior surface. A microphone, disposed within the microphone retaining chamber, has a first acoustic port in an acoustic relationship with the first acoustic passage and a second acoustic port in an acoustic relationship with the second acoustic passage. A first and second set of electrical leads are disposed within the housing. A switching mechanism secured to the housing and is positionable between a first position and a second position. In the first position, the first and second acoustic passages are in an acoustic receptive state and a first electric circuit is completed by connecting the first set of leads with a first connecting element disposed within the switching mechanism while breaking a second circuit.

Abstract: Audio-processing devices are known generally. When such an audio device wants to use as input signals from another device de audio device has to determine whether the received input signals are mono signals or stereo signals.

Abstract: The present invention provides an audio system in an electronic musical instrument which can determine the characteristics of a reproduced sound automatically or simply for matching with the environment.

Abstract: A sound image localization apparatus comprises crosstalk canceling means and direction localizing means, wherein first the crosstalk canceling means first subject an input sound signal to crosstalk cancellation, and then, the direction localizing means subject the processed signal to directional localization, whereby both crosstalk cancellation and directional localization share a signal to be processed, so the necessary amount of a storage device to hold the signal is reduced. That is, a reduction in circuit scale and calculation load can provide a sound image localization apparatus with low cost and high processing precision.

Abstract: A head worn apparatus having a pair of rearwardly disposed elongated support arm assemblies having movable portions which are positionally adjustable to provide increased wearer comfort attached to a head-worn device such as a visor or eyeglasses. The support arm assemblies each include a an articulating segment and/or head gripping region pivotally coupled to the head-worn apparatus. The articulating segment include means for providing a constant inward compressive force by means of increased resistance for rotating articulating segments outwardly, thereby securing the head-won device onto a wearer's head.

Abstract: An audio storing and reproducing apparatus is provided that has a semiconductor chip and a control unit. The semiconductor chip includes a semiconductor memory having a plurality of storage areas, a single storage specifying input terminal, a single reproduce specifying input terminal, and a storage medium controller that controls storing of the audio data to the storage areas and readout of the audio data therefrom in accordance with the signal input to the storage specifying and reproduce specifying input terminals. The control unit includes a single storage area specifying switch, a single storage specifying switch, a single reproduce specifying switch and a control circuit.

Abstract: A method for configuring an audio interface for a speech recognition application in a computer system comprises the steps of: (a) displaying a first graphical user interface prompting a user selection of an output audio device between: a headset having at least one earphone speaker and a microphone; external speakers connected to the computer system; and, internal speakers connected to the computer system; (b) in the event of the user selecting the headset: (1) displaying a second graphical user interface for prompting a user to connect the headset; (2) displaying a second graphical user interface illustrating proper placement of the headset and the microphone; and, (3) displaying a fourth graphical user interface for adjusting audio playback volume;(c) in the event of a user selecting one of the external and internal speakers, omitting displaying the second and third graphical user interfaces as in steps (b)(1) and (b)(2) respectively, and displaying the fourth graphical user interface as in step (b)(3).

Abstract: A battery circuit for coupling a battery source to an electret microphone. The circuit includes impedance circuitry for providing appropriate bias impedance for a desired microphone sensitivity, and disconnect circuitry for automatically disconnecting the battery source from the electret microphone in response to detecting a low voltage state in order to prevent distortion and low output level of the microphone. In an alternative embodiment of the invention there is provided second impedance circuitry for driving corresponding inputs with minimal loss. In another alternative embodiment of the invention there is provided a compensation circuit which operates to extend battery source life and prevent lower output at lower voltage.

Abstract: A signal output is taken out from the input stage or respective output stages of the signal characteristic processing means through a signal line selected by selecting means. In accordance with the taken signal, the level control signal generating means sets the output level of the audio output signal. Then, the output level setting means sets the output level of the audio output signal in accordance with the level control signal outputted by the level control signal generating means. Therefore, the switching noise due to switch signal lines by selecting means is prevented from entering into an audio output signal during the processing of the output level of the audio input signal.

Abstract: When a first bi-wiring speaker is connected to output terminals 5A and 5B and a second bi-wiring speaker is connected to output terminals 5D and 5E, and further a two-channel stereo reproduction is performed, a signal 3L for a L channel outputted from a decoder 2 is amplified by amplifiers 4A and 4B in parallel to be given to the first bi-wiring speaker in a bi-wiring connecting manner and a signal 3R for a R channel outputted from the decoder 2 is amplified by amplifiers 4C and 4D in parallel and given to the second bi-wiring speaker in a bi-wiring connecting manner. At this time, a gain corrector 7 equalizes a gain which an output signal of the amplifier 4A has with respect to the signal 3L for the L channel with a gain which an output signal of the amplifier 4B has with respect to the signal 3L for the L channel.

Abstract: A method for offset compensation of a signal processing circuit in whose signal path a circuit configuration with offset is disposed, wherein the circuit configuration with offset is temporarily decoupled from the signal path of the signal processing circuit and meanwhile held strictly in a dc mode; a compensating dc voltage is added to the output dc voltage occurring at the output of the circuit configuration with offset in the dc mode, said compensating dc voltage being varied until the cumulative value of output dc voltage and compensating dc voltage has became zero; the circuit configuration with offset is then coupled into the signal path again; andfrom then on the compensating dc voltage occurring at the cumulative value zero is permanently added to the output signal of the circuit configuration with offset until a new offset compensating process is performed.

Abstract: An audio transmission apparatus has a primary speaker and a secondary speaker apparatus. Two primary speakers are provided to correspond with the left channel and the right channel. The secondary speaker apparatus is placed on a first surface of the primary speaker. A switching mechanism, such as a micro switch or a proximity sensor, is disposed between the primary speaker and the secondary speaker apparatus such that removal of the secondary speaker apparatus enables the secondary speaker apparatus and disables the primary speaker. Connected by wire or a wireless medium, the secondary speaker apparatus is an earphone, a head set, or an ear bud, depending on the application. The audio transmission apparatus is used in conjunction with any type of audio output device, such as a television, computer, stereo, and the like.

Abstract: The apparatus according to the present invention is provided with two or more output systems to which transducers are connected, a source output on/off control unit that turns on/off the output from a source based upon the output from a random signal generating unit and a frequency varying unit that causes changes in the frequency of an electrical signal provided to the transducers over time at a specific rate. Every time the source output is turned off, the output of the electrical signal is stopped and the output systems are switched over, whereas when the source output is on, the electrical signal provided to the transducers on the output system to which the signal is to be provided. Since the output systems are switched over to be selected for use, it becomes possible to connect a greater number of transducers while using the same source capacity as in the prior art and noise generated from the transducers, when switching over the output systems, is eliminated.

Abstract: A connector device for connecting information-handling apparatus has a common jack connected to a first information-handling apparatus, a plurality of plugs connected respectively to a plurality of second information-handling apparatus having respective different impedances, the plugs being selectively connectable to the jack, and a determining circuit for, when one of the plugs is connected to the common jack, applying a predetermined voltage to a contact of the connected plug through an impedance element, detecting a voltage between the contact of the connected plug and a ground contact thereof, detecting an impedance between the contact of the connected plug and the ground contact thereof depending on the detected voltage, and determining the type of the plug or the type of the second information-handling apparatus connected to the plug depending on the detected impedance.

Abstract: Receiver control circuitry of a receiver automatically detects, selects, and enables a priority signal provided to the receiver from a plurality of audio and/or visual source devices. Upon the user starting a source device that serves as a potential source of audio and/or visual input signals to the receiver, the receiver control circuitry automatically determines whether the receiver should switch to the source device as its source of audio and/or visual information. Additionally, the receiver control circuit will automatically turn on the receiver if it is not powered-up so that this will not have to be done by the user of the receiver.

Abstract: The subject invention relates to a type of multi-functional audio & video control box, comprising such components as an antimagnetic speaker box and several sets of audio/video selector whereby an audio/video connection switch box and an audio input/output speaker switch functions are completely integrated inside an antimagnetic speaker box, so as to very efficiently save space, with possible designing and combination of easily operated switches.

Abstract: A speech processor uses at least two speech processing features to enhance the quality of speech signals received by a user during a telephone call. The speech processing features are applied to the speech signals. However, the user only hears speech signals affected by one speech processing feature until both features have fully converged or ramped-up, and the two features are no longer interfering with each other. At that point, a "flash-cut" of the second speech processing feature is activated. The flash-cut instantaneously switches to speech signals affected by both features. This quick transition makes the speech processing features more noticeable to the user, and the user is not subjected to the period where the features interfere. Further, an optional audio indicator is generated before implementing the flash-cut, so the user is alerted to the flash-cut, and the speech processing features are even more noticeable.

Abstract: A system and method for multiplexing control signals over data signal conductors comprises an audio source for generating audio signals, a speaker device for monitoring the audio signals, a first high-pass filter for filtering the audio signals, a signal cable over which the audio signals are transmitted, a second high-pass filter for again filtering the audio signals, and headphones for monitoring the audio signals. The system and method further comprises a current source for generating a control signal whenever the headphones are connected and for transmitting the control signals over the signal cable, and a detector device for receiving the control signals and responsively using them to mute the speaker device.

Abstract: The present invention discloses a power circuit for a condenser microphone capable of automatically switching both internal power source and external power source without carrying out the switching operation of a switch. A positive side output line comprises a power switch for turning off the positive side output line to selectively connecting it to a ground side output line; a first diode connected with an input direction from the external power source being a forward direction between the power switch and an output terminal of the positive side output line; and a capacitor connected parallel with said power switch and said first diode so as to bypass them, a series circuit comprising the internal power source, a second diode and a load resistor with a direction from the ground side output line to the positive side output line being a forward direction being connected between a connection point of the power switch and the first diode and the ground side output line.

Abstract: Stereophonic sound reproduction apparatus comprising an input means (2) for producing binaural signals, cross-talk cancellation means, (10) loudspeaker means, (20, 22) headphone means, (26) and a switch means (12, 18, 24, 30, 32) which in a first position (plug 24 not inserted in socket 18) couples the binaural signals from the input means (2) to the loudspeaker means (20, 22) through the cross-talk cancellation means (10) and in a second position (plug 24 inserted in socket 18) renders the cross-talk cancellation means (10) inoperable and couples the binaural signals from the input means (2) to the headphones (26).

Abstract: Dual program audio apparatus is provided having two or more sources of input audio program signals, switching circuitry for selecting two of the input audio signals for amplification, one or more amplifiers for amplifying the selected input audio program signals, and one or more audio speakers for enabling a listener to hear both audio programs simultaneously. Volume control circuitry is provided for selecting a higher volume level for a foreground program and a relatively lower volume for a background program and circuitry is provided for selectively interchanging the foreground and background programs either instantaneously or gradually and continuously.

Abstract: A computer for handling audio signals includes, within one box, programmable digital processing circuitry, read/write memory, digital-to-analog circuitry, one or more speakers, and an equalization element for altering the frequency response of signals applied to the speaker. The equalization element can be used to boost low frequency signals sent to the speaker if the speaker has poor low frequency response. Preferably the computer also has headphone and line-out jacks to which it supplies un-equalized audio outputs. The computer's internal speaker can be driven by a bridge mode amplifier, and, to save space, the speaker's electro-magnetic transducer can be placed in the concave recess formed by its speaker cones. The computer can have two speakers to play stereo. Preferably the computer receives analog inputs, such as from a built-in CD-ROM drive, a mike-in jack, and a line-in jack, and uses an analog-to-digital converter to digitizes these signals so they can be digitally manipulated by the computer.

Abstract: A method and apparatus for synchronizing AES digital audio signals for switching clocks each signal into a respective buffer under control of a recovered clock from each signal. A sync detector for each signal identifies a synchronizing symbol and enables the loading of the corresponding buffer starting with the synchronizing symbol. A common clock is applied to all of the buffers starting with a system sync signal to read out all of the buffers simultaneously in synchronization with each other so that when switched, there is no corruption of the output AES digital audio signal that might cause a "pop" to be heard.

Abstract: A microphone including an infrared switch circuit is disclosed. The infrared switch circuit includes an infrared detector for detecting a reflection of an infrared signal off an object such as a human body, and producing an electrical signal. The circuit also includes an amplifier for amplifying the electrical signal and a comparator for determining if the amplified electrical signal is above a predetermined threshold. The switching finally includes a audio switching network for providing the amplified signal as an audio signal if the amplified signal is above a predetermined threshold. The circuit also includes power conservation techniques to improve performance.

Abstract: An audio system includes a light sensitive switch connected to a microphone. Activation of the microphone operates the switch, thereby indicating that the microphone is in use. When the user turns the microphone on, a voltage is applied across a light emitting diode which causes the diode to emit light. The light activates the light sensitive switch which is connected to the remainder of the audio system. The system interprets activation of the light sensitive switch as an indication that the microphone is in use and responds accordingly.

Abstract: A videoconferencing system is provided which comprises a personal computer having a 32-bit multi-tasking, native-networking operating system and a touch screen graphic user interface for controlling the system. The videoconferencing system is configured for the integration of applications programs, the transfer of data outside the bandwidth of a videoconference and remote diagnostics. Circuits for pooling CODECs and bridging audio signals are also provided.

Abstract: A dispatcher console for use in a digitally trunked, multisite public service radio system. The dispatcher counsel comprises a personal computer having a co-processor logic board, an audio switching tower, and user I/Os including a customized keyboard, display screen, audio speakers, headset and a transmit foot pedal. The switching tower routes audio communications between the console and multisite switch. The tower is controlled by and connected directly to the co-processor board. The customized keyboard is also connected directly to the co-processor board and has dedicated keys for commonly performed functions. The display screen presents information in a standard format such that the dispatcher knows precisely where to find particular information.

Abstract: A circuit system for selectively switching between main and remote loudspeakers includes a pair of input terminals for applying an input audio signal to the loudspeakers. A first selector switch contact is provided in series with the main loudspeakers. A second selector switch contact is provided in series with the remote loudspeakers. A current-dependent resistance element is provided in series with the remote loudspeakers to protect the remote loudspeakers from overdrive. The circuit system may also include a second current-dependent resistance element and a cooperating defeat switch contact as well as a resistor and associated load limiting switch contact all in series with the remote loudspeakers.

Abstract: This invention is an emulation of vacuum tube guitar amplifier with devices that emulate vacuum tube plate voltage and current characteristics. This amplifier system has a switching system for selecting preamplifiers and which alters the behavior of the output stage by changing features such as feedback and compression character. The preamplifier and output stages use non-linear means for the emulation of triode amplifiers, cathode followers, phase splitters, and pentode amplifiers. The features emulated are the grid conduction with scaling and offsetting, current gain, plate voltage and current characteristics, and compression.

Abstract: A portable telephone includes a main body of the telephone, a transducer (preferably an earphone) contained in the main body so that it can be removed therefrom, a cord connecting the transducer and the main body, and a switching mechanism. The portable telephone further comprises transmitting means and a transmission/reception circuit. In one embodiment of the present invention, the switching mechanism switches between an off-hook state and an on-hook state in conjunction with the removing and containing of the transducer from and into the main body of the telephone preferably through the delivery or taking up of the cord from and into the main body of the telephone. In a second embodiment, the portable telephone further includes a hinged lid which is rotatably supported to close an opening provided in the main body.

Abstract: Dual program audio apparatus is provided having two or more sources of input audio program signals, switching circuitry for selecting two of the input audio signals for amplification, one or more amplifiers for amplifying the selected input audio program signals, and one or more audio speakers for enabling a listener to hear both audio programs simultaneously. Volume control circuitry is provided for selecting a higher volume level for a foreground program and a relatively lower volume for a background program and circuitry is provided for selectively interchanging the foreground and background programs either instantaneously or gradually and continuously.

Abstract: A wireless audio system, including an audio and radio frequency module, that is prevented from being accidentally turned off by using an electronic gate responsive to a gate signal for coupling electrical power from a source to the module which bypasses the normal mechanical power switch. Means are provided for generating the gate signal in response to operation by the user so that the user cannot accidentally turn off the system by moving the power switch to its off position.

Abstract: An automatic microphone control system particularly suited to controlling a small, predetermined number of microphones. A representation of the level of a microphone signal is compared individually to the level representations of each of the other microphones to determine if the microphone should receive a gating trigger. If the microphone level compares favorably to each of the other microphones, and a noise adaptive threshold comparison criterion is also satisfied, then the microphone receives a gating trigger. This triggers a gate ON action for the microphone, which is held at least 0.4 seconds by a one-shot and also locked ON unless a gate ON action is initiated by any other microphone. The circuitry for a two-microphone system particularly suited to a lectern application is powerable by a conventional phantom-powering balanced microphone preamplifier input.

Abstract: An apparatus for multiplexing audio signals in a disc-shaped video-song medium which includes a plurality of digital audio channels having stereo accompaniment music recorded therein, and a plurality of analog channels having stereo accompaniment music which includes a singer's singing voice, and playback system thereof, are disclosed. When the video-song mode is established, the apparatus for multiplexing the audio signals adjusts the audio levels of both the stereo accompaniment music and the stereo accompaniment music that includes a singer's singing voice to adequate audio levels by means of an audio level adjustment responsive to a change in the resistances in the variable resistors included in an audio multiplexing section. The apparatus multiplexes the audio signals. Accordingly, the user can effectively practice a video-song in harmony with either the stereo accompaniment music or the stereo accompaniment music that includes a singer's singing voice.

Abstract: In a mono/stereo input circuit for use in an audio equipment, and more particularly in a circuit for automatically recognizing and receiving mono/stereo audio signals, although a mono connector is inserted into a stereo jack, such an insertion of the mono connector is automatically recognized and then a stereo circuit can operate as a form of a mono circuit. The circuit for automatically recognizing and receiving the mono/stereo audio signals utilizes a fact that one connection terminal of the jack is grounded or not according to a type of the connector such as a mono connector and a stereo connector which is inserted into the jack. Accordingly, a resistor used as a voltage generator generates a generation voltage according to such a connector recognition. Also, using a difference between the generated voltage, the analog switches are turned on or off, to obtain a mono or a stereo audio signal processing circuit according to a type of the inserted connector.

Abstract: A headphone sound system apparatus includes headphones and a sound system having an output line for the headphones for producing audio signals to the headphones. The sound recognition and interrupt system has the sound system output coupled thereto and to the headphones and has a housing which can be attached to the person, such as being clipped to a belt. The housing has a microphone mounted inside for picking up sounds extraneous to the sound system and a switching circuit mounted in the housing and connected to the microphone and which is actuated by the microphone between on and off positions responsive to signals of predetermined levels being generated by the microphone. The switching circuit disables the connection from the sound source so that a person wearing the headphones has the sound system turned down to thereby be able to hear the extraneous sound that actuated the switching circuit. The switching circuit is manually actuated to reconnect the sound source to the headphones.

Abstract: A simple and effective stereophonic transmission system (1) wherein the transmitter (2) alternatively encodes successive block periods of a block signal with samples of the left-hand channel signal (L.sub.in) and the right-hand channel signal (R.sub.in). At receiver side, the left-hand and right-hand stereo signals are decoded from the encoded block signal by alternate integration and peak detection of positive and negative received pulses, the pulse widths of the received pulses corresponding to amplitudes of the transmitted samples. When detecting the pulses for one stereophonic channel, the corresponding other stereophonic channel is blocked.

Abstract: Audio apparatus demonstrating includes audio apparatus to be demonstrated. A display structure supports the audio apparatus and a digital computer controller. A CD-ROM is coupled to the audio apparatus and the digital computer controller with recorded sound signals for audible reproduction by the audio apparatus in response to selection signals furnished by the digital computer controller. A start demonstration switch is coupled to the digital computer controller. A proximity sensor provides a proximity signal to the digital computer controller when a person enters a predetermined zone around the apparatus to cause the digital computer controller to select a change in the record signal reproduced by the audio system from a first signal to a second signal which second signal encourages the person within the zone to actuated the start demonstration switch and initiate a demonstration of the audio apparatus including audibly reproducing sound signals recorded on the CD-ROM.