Abstract: A headphone down mix signal can be efficiently derived from a parametric down mix of a multi-channel signal, when modified HRTFs (head related transfer functions) are derived from HRTFs of a multi-channel signal using a level parameter having information on a level relation between two channels of the multi-channel signals such that a modified HRTF is stronger influenced by the HRTF of a channel having a higher level than by the HRTF of a channel having a lower level. Modified HRTFs are derived within the decoding process taking into account the relative strength of the channels associated to the HRTFs. The HRTFs are thus modified such that a down mix signal of a parametric representation of a multi-channel signal can directly be used to synthesize the headphone down mix signal without the need of an intermediate full parametric multi-channel reconstruction of the parametric down mix.

Abstract: An audio player apparatus includes a first speaker disposed to output a sound from a front face of a flat panel television apparatus to the outside, a second speaker disposed to output a sound from a backside of the flat panel television apparatus to the outside, a microphone disposed on the backside of the flat panel television apparatus to receive the sound output from the second speaker and to convert the received sound into an electric signal, an analysis unit configured to detect a reflected sound and reflection time of the sound output from the second speaker based on a second audio signal supplied to the second speaker and the electric signal output from the microphone, and a phase correction unit configured to correct a phase of at least one of a first audio signal supplied to the first speaker and the second audio signal based on the reflection time.

Abstract: A loudspeaker configuration capable of generating stereophonic sound separation from relatively loudspeaker drivers that are not necessarily widely separated. For example, such a loudspeaker configuration can be used to generate relatively good sound separation from a single chassis, such as a single speaker box, a boom box, a clock radio or the like. This can advantageously save space in many environments. One embodiment uses four mid-tweeter speaker drivers and a bass driver. The four mid-tweeter speaker drivers are arranged facing outward approximately 90 degrees apart from each other. A speaker driver facing the listener reproduces a mid channel signal, for example, L+R. A speaker driver facing away from the listener reproduces the same mid channel signal or a delayed version of the mid channel signal. A left facing speaker reproduces a side channel, for example, L?R. A right facing speaker reproduces a side channel, for example, R?L.

Abstract: Multiple channels of audio are combined either to a monophonic composite signal or to multiple channels of audio along with related auxiliary information from which multiple channels of audio are reconstructed, including improved downmixing of multiple audio channels to a monophonic audio signal or to multiple audio channels and improved decorrelation of multiple audio channels derived from a monophonic audio channel or from multiple audio channels. Aspects of the disclosed invention are usable in audio encoders, decoders, encode/decode systems, downmixers, upmixers, and decorrelators.

Abstract: A virtual multichannel sound system is presented to improve audio reproduction by statically or dynamically conforming signal processing to specific speaker characteristics and/or arrangements. According to one such aspect, one or more dynamic signal processing algorithms driving two or more speakers are altered in response to the relative physical characteristics or arrangements of these speakers, where parameter information for these algorithms is either factory set, user input, or automatically supplied to the processor. Examples of such relative speaker differences include speaker spacing or alignment, speaker or enclosure compliance, and enclosure configuration. Another aspect is to alter the processing algorithms in response to common speaker characteristics for certain conditions of input signals.

Abstract: An automotive virtual surround audio system is implemented in an automobile to receive left- and right-channel audio sources. A synthesizer receives the left- and right-channel audio sources to extend the sources into temporary rear-left and rear-right audio sources. A weighting device receives the left- and right-channel audio sources to perform a weighting operation and produce temporary front-left and front-right audio sources. A first filter receives the temporary front-left and front-right audio sources to perform a filtering operation and produce virtual front-left and front-right audio sources. A second filter receives the temporary rear-left and rear-right audio sources to perform a filtering operation and produce virtual rear-left and rear-right audio sources. Thus, the virtual audio image position is reproduced.

Abstract: An audio system that provides an optimized sense of realism and an optimized three-dimensional effect to a user, the audio system including: a horizontal plane speaker set including a center channel speaker that is disposed at a reference point, a left channel speaker and a right channel speaker that are disposed at points in right and left directions of the reference point, and at least one first channel speaker and at least one second channel speaker that are disposed in right and left directions of the reference point, respectively; and a vertical plane speaker set including a left height channel speaker and a right height channel speaker that are respectively disposed in right and left directions of the reference point and in a vertical direction of the reference point, and a center height channel speaker that is disposed in the vertical direction of the reference point.

Abstract: A wireless multi-channel audio system including an audio source with a wireless transceiver configured to communicate according to a standard wireless protocol and an audio controller, which are collectively configured to establish wireless communications with multiple audio sinks via a corresponding wireless link, to assign each audio sink a corresponding audio channel, to synchronize timing with each audio sink, and to transmit audio information for each audio channel to a corresponding audio sink via a corresponding wireless link. The audio source may inquire as to supported audio parameters, such as sample rate and audio codec, and selects a commonly supported configuration. The audio source may separate audio information into queues for each audio channel for each audio sink. The audio source transmits frames with timestamps and a common start time for synchronization, and the audio sinks use this information to synchronize timing and remain virtually synchronized with each other.

Abstract: An audio system utilizes a method for detecting and adjusting a sound field effect thereof. The audio system includes a first speaker and a second speaker. The first speaker is used to emit a first sound signal, and the second speaker is used to emit a second sound signal. The method for adjusting the sound field effect includes the steps of detecting a specific position and adjusting the first speaker or the second speaker based on the specific position to focus the first sound signal and the second sound signal on the specific position.

Abstract: A surround sound outputting device includes a receiving portion which receives signals on a plurality of channels, a storing portion which stores measuring sound data representing a sound, an outputting portion which outputs a sound produced based on the signals on the plurality of channels or the measuring sound data in a controlled direction and in a beam shape, a controlling portion which controls a direction of the sound output from the outputting portion, a sound collecting portion which picks up the sound output from the outputting portion to produce picked-up sound data representing the picked-up sound, an impulse response specifying portion which specifies impulse responses in respective directions from respective sound data, a path characteristic specifying portion which specifies path distances of the paths through which the sounds output in the respective directions arrive at the sound collecting portion from the outputting portion and levels of the impulse responses based on the impulse responses

Abstract: A multichannel audio system for radiating sound to a listening area that includes a plurality of listening spaces. The audio system includes directional audio devices, positioned in a first of the listening spaces, close to a head of a listener, for radiating first sound waves corresponding to components of one of the channels and nondirectional audio devices, positioned inside the listening area and outside the listening space, distant from the listening space, for radiating sound waves corresponding to components of a second of the channels.

Abstract: In an audio signal reproduction device and an audio signal reproduction system of the present invention, an SLch sound is reproduced as a mixed sound that is adjusted appropriately by two speakers 5a, 5d located at Lch and SBLch speaker positions, and an SRch sound is reproduced as a mixed sound that is adjusted appropriately by two speakers 5b, 5e located at Rch and SBRch speaker positions. This configuration can achieve 5.1ch virtual reproduction with high sound quality in which sounds for 5.1 channels of LPCM 7.1ch audio information included in the contents are output as they are and sounds for the remaining 2 channels are reproduced artificially even if speakers compatible with the 5.1ch sound field system are connected.

Abstract: An audio signal is supplied to a loudspeaker array to perform wavefront synthesis. A virtual sound source is produced at an infinite distance using wavefront synthesis. A propagation direction of a sound wave emitted from the virtual sound source is changeable.

Abstract: A method and apparatus for reproducing a front surround sound, whereby a coefficient of at least one beamforming filter set is determined based on a sound pressure ratio of an emphasis area to a suppression area for each of the at least one channel signal included in a sound signal, where the emphasis area is an area into which the at least one channel signal is focused and the suppression area is an area within which the at least one channel signal is blocked, the at least one channel signal passes through a corresponding beamforming filter set, and the at least one filtered channel signal is output through an array speaker.

Abstract: A method includes splitting and filtering a left input signal and a right input signal to produce a plurality of frequency sub-bands. Each of the frequency sub-bands includes a left sub-band signal and a right sub-band signal. The method also includes processing the left and right sub-band signals associated with each of the frequency sub-bands into a plurality of sub-band channel signals. The plurality of sub-band channel signals includes at least three sub-band channel signals. In addition, the method includes summing corresponding ones of the sub-band channel signals for reproduction in a corresponding channel of a plurality of channels. The plurality of sub-band channel signals may include a left sub-band channel signal, a right sub-band channel signal, a center sub-band channel signal, a left surround sub-band channel signal, and a right surround sub-band channel signal.

Abstract: A spatial processing stereo system (“SPSS”) that receives audio signals and a limited number of user input parameters associated with the spatial attributes of a room, such as “room size”, “stage distance”, and “stage width”. The input parameters are used to define a listening room and generate coefficients, room impulse responses, and scaling factors that are used generate additional surround signals.

Abstract: The two channel audio surround sound circuit with automatic level control includes a right amplifier, a left amplifier, a right automatic level control and a left automatic level control. A right input is coupled to a positive input of the left amplifier through the right automatic gain control. The right input is coupled to a negative input of the right amplifier and coupled to the output of the right amplifier with one resistor. A left input is coupled to a positive input of the right amplifier through the left automatic gain control. The left input is coupled to a negative input of the left amplifier and coupled to the output of the left amplifier with another resistor.

Abstract: A tracking system may determine the orientation or position of a movable object. The tracking system includes a signal generator that generates a non-audible detection signal in an audible frequency range. A transmitting device transmits the detection signal to a detection device. The transmitting device or the detection device may be positioned on the movable object, and the other may be positioned at a remote location. A processor may determine an orientation or position of the moveable object based on the transmission time between the transmitting device and the detection device.

Abstract: An active audio matrix decoding method and apparatus to generate multi-channel audio signals from a stereo channel audio signal.

Abstract: Mobile terminals having three dimensional audio capabilities for making sound appear to originate from any location within a three dimensional space and to facilitate navigational movement among displayed information are provided. A mobile terminal includes a housing that encloses a processor and one or more speakers. A display is located on the housing that is in communication with the processor, and a keypad is located on the housing that is in communication with the processor and that is responsive to user input for navigating a cursor within the display. The mobile terminal includes a three dimensional audio system that is in communication with the processor and speaker(s). The three dimensional audio system audibly indicates navigational movement of the cursor in the display, and is configured to make sound emitted by the speaker(s) appear to originate from any of a plurality of locations in a virtual three dimensional space.

Abstract: Vehicle audio systems including directional loudspeakers, particularly directional arrays. An exemplary audio system for a vehicle includes a plurality of audio channels. The vehicle includes a first passenger position and a second passenger position ahead of the first passenger position. The audio system includes a first directional loudspeaker positioned ahead of the first passenger position and in back of the second passenger position, constructed and arranged to radiate directionally a first audio channel so that a direction toward the first passenger position is one of a low radiation direction and a high radiation direction and so that a direction toward the second passenger position is the other of a low radiation direction and a high radiation direction.

Abstract: Processing an audio signal associated with a sound recording made available to be rendered to an end user is disclosed. The audio signal is received. A high-order perceptual attribute of the audio signal as rendered is changed by modifying the audio signal. The modification may be based on real-time analysis of the audio signal.

Abstract: An awning includes a base part, which can be attached to a building part, a fabric shaft rotatably mounted thereon, an awning fabric, which can be retracted and extended and can be wound onto the fabric shaft and unwound therefrom, and a sound production system, which has a driver controller and at least one sound actuator activated thereby and coupled to an awning component, wherein the at least one sound actuator causes the awning component to carry out defined oscillations to emit a sound signal, in particular a music and/or speech signal.

Abstract: A sound system, the sound system including: (a) a signal processor that is adapted to generate a first sound signal and a second sound signal, to provide the first sound signal to a loudspeaker; and to provide the second sound signal to a bone conduction speaker; and (b) the bone conduction speaker that is adapted to transduce the second signal to a bone conductible sound signal that is carried in a bone of a user.

Abstract: Preserving an audio signal in an audio system includes selecting a first audio signal from a plurality of audio signals. The first audio signal is applied to a first transducer. Mix a portion of the first audio signal with a second audio signal from the plurality of audio signals to provide a mixed audio signal. A gain of the first audio signal that is applied to the first transducer is decreased while a portion of the mixed audio signal is applied to a second transducer to preserve at least a portion of the first audio signal.

Abstract: In a multichannel amplifier according to the present invention, in a case where a headphone is not connected to a headphone output terminal, a switch IC and first to third switches are on/off controlled by a control unit so that an audio signal path for outputting a front channel signal FL/FR to a front speaker and extending from a first input terminal 1 to a front speaker output terminal 6 via a buffer circuit 10a, a switch IC 9, a first volume control unit 3a, a buffer circuit 10b, and a first amplifying unit 4a is not electrically connected to another audio signal path.

Abstract: A sound field control apparatus, which offers clear sound quality of speech and voice of a center channel signal, a wide service area, and a level easily perceived, and also achieves 5.1 sound image localization and the sense of reality by a two-channel loudspeaker structure, is implemented by a simple structure. The sound field control apparatus includes: adders (4, 5, 10, 12), a delay unit (9), and an inverting unit (11) for achieving the clear sound quality of speech and voice of a center channel signal; a VCA (3), a maximum value detection unit (6), a level comparison unit (7), and a level control unit (8) for controlling a level to be easily perceived; delay units (15, 16) and sound quality modification equalizers (17, 18) for achieving the same sound quality and sound image localization of surround signals from among 5.1 channel signals by using surround channel loudspeakers so as to obtain 5.

Abstract: There is provided a surround-sound system in which the output direction of a sound beam of each channel in a speaker array can be optimized without requiring a user to make any troublesome operation. A parameter setting control portion 6 controls to output sound beams from a speaker array 1 and rotate the output directions of these sound beams. In addition, based on change of sound pressure sensed by a microphone 7 when the output directions of the sound beams are rotated, the parameter setting control portion 6 determines the output directions of sound beams of at least a part of a plurality of channels in the speaker array 1. The parameter setting control portion 6 determines the output directions of sound beams of the other channels based on the output directions of the channels determined based on the change of sound pressure.

Abstract: With stereophonic sound images of multi-channel audio signals well maintained, 2-channel system audio signals are created. An acoustic image creation system includes: a left-rear localization processing means 2 for outputting a left-rear localization signal by summing together a left signal 101 and a left-rear signal 103, among audio input signals including the left signal 101, a right signal 102, the left-rear signal 103, and a right-rear signal 104, and processing the summation result with a rear localization processing filter; a right-rear localization processing means 3 for outputting a right-rear localization signal by summing together the right signal 102 and the right-rear signal 104, and processing the summation result with a rear localization processing filter; and an acoustic image creation means 4 for creating the surround sound image signals from the left signal 101, the right signal 102, the left-rear localization signal 103, and the right-rear localization signal 104.

Abstract: An audio processing system which allows a surround sound system to utilize the transmission bandwidth efficiently by adaptively transmitting a supplementary data from a secondary source in addition to the audio signals of a primary source. The system consists of a transmitter component, capable of transmitting audio signals from a primary source and adaptively inserts supplementary data of the secondary source in the reserved communication bandwidth. The transmitter inserts headers in the channels used by the supplementary data to allow the receivers to identify the channel allocation between the primary source and the secondary source. Another part of the audio processing system is that of a receiver component which is capable of discriminating between data from the primary source and data from the secondary source.

Abstract: An improved method and materials for retaining small loudspeakers to a platform composed of adjustable connecting miniaturized members utilizing international standards for surround sound in meters, but reduced to inches. One example would be a scale of one inch equaling one foot, but not limited to that particular miniature scale. The present invention utilizes any and all technical aspects of sound delivery and amplification in a miniature scale arrangement with the multi-directional surround sound. The speakers so mounted in measured inches from the center-point midway between the ears of the listener, delivers multi-directional sound in a re-creation of a musical, movie or gaming experience in the same perspective as being in a room with large speakers at high listening levels or a theater setting. Listening in the miniaturized setting, the listener will experience the same high levels in decibels as in the large room setting.

Abstract: An audio processing apparatus comprising: channel determination section for determining which one of a combination of the first left audio signal and the first right audio signal and a combination of the second left audio signal and the second right audio signal is included in multichannel audio data; and switching section for causing the first amplification section to amplify the first left audio signal and supply the amplified first left audio signal to the first speaker terminal and causing the second amplification section to amplify the first right audio signal and supply the amplified first right audio signal to the second speaker terminal when the combination of the first left audio signal and the first right audio signal is determined to be included; and causing the first amplification section to amplify the second left audio signal and supply the amplified second left audio signal to the third speaker terminal and causing the second amplification section to amplify the second right audio signal and su

Abstract: A method for generating and playing audio signals and a system for processing audio signals are disclosed. The method for generating audio signals includes: generating distance information about an audio signal corresponding to a view point position, according to obtained auxiliary video and direction information about the audio signal, where the auxiliary video is a disparity map or a depth map; encoding the direction information and distance information about the audio signal, and sending the encoded information. The apparatus for generating audio signals includes an audio signal distance information obtaining module and an audio signal encoding module. With the present invention, the position information, including direction information and distance information, about the audio signal may be obtained accurately in combination with a three-dimensional video signal and a three-dimensional audio signal, without increasing the size of a microphone array, and the audio signal is sent and played.

Abstract: A sound reproduction system comprises a left and right speakers located in close proximity, and a sound processor which provides audio signals to the pair of speakers. The sound processor preferably derives a cancellation signal from the difference between the left and right channels. The resulting difference signal is scaled, delayed (if necessary), and spectrally modified before being added to the left channel and, in opposite polarity, to the right channel. The spectral modification to the difference channel preferably takes the form of a low-frequency boost over a specified frequency range, in order to restore the correct timbral balance after the differencing process. Additional phase-compensating all-pass networks may be inserted in the difference channel to correct for any extra phase shift contributed by the spectral modifying circuit. The technique may be used in a surround sound system.

Abstract: The invention features a dual-mode audio system for an automobile which in one mode is configured for play while the doors to the automobile are closed, and in a second mode, is configured for play while a door, such as a tailgate, is opened. Additionally, the invention also features a battery monitor which monitors the operating condition of the battery and may estimate the energy capacity of the battery. The system may also take power conservation measures if the system determines that the engine is not running or the operating condition of the batter reaches a predetermined state. The invention also features a remote control integrated within a key fob for controlling the audio system. The invention features various orientations for mounting a pair of loudspeakers within an automobile which directly radiate sound out of a rear opening of the automobile.

Abstract: Interlocking flag, indicating whether or not an interlocked display should be made, can be set in association with predetermined editing operators. When any of the operators is operated, a displayed screen on a display is switched over to a screen related to the operated operator, if the interlocking flag associated with the operated operator indicates flag-ON; if not, the display device may be used to perform another function. A plurality n of channels may be divided into a plurality of layers each consisting of predetermined number m channels. It is only necessary that a limited number of operators, e.g. faders, be provided to correspond to a single layer, i.e. m channels. Any of the layers is selected, and any of the operators is used for the selected layer. A set of stereo channels can be set across different layers so as to interlock with each other in response to editing operation of the operator.

Abstract: A sound image localization apparatus comprises an L direct output section that produces an output signal by inputting an audio signal of a rear left audio input channel to a filter having a characteristic obtained by dividing RLD by LD, an L cross output section that produces an output signal by inputting the audio signal of the rear left audio input channel to a filter having a characteristic obtained by dividing RLC by LC, an R cross output section that produces an output signal by inputting an audio signal of a rear right audio input channel to a filter having a characteristic obtained by dividing RRC by RC, an R direct output section that produces an output signal by inputting the audio signal of the rear right audio input channel to a filter having a characteristic obtained by dividing RRD by RD, a first adding section that adds a difference signal between the output signal of the L direct output section and the output signal of the R cross output section to an audio signal of a front left audio input ch

Abstract: An audio device capable of easily generating two or more sets of surround signals based on 2-channel stereo signals and a method for generating surround sound are provided. The audio device 100 includes: an SL signal generation section 20 and a BL signal generation section 40 as first surround signal generation units for receiving an L signal and an R signal as 2-channel stereo signals, extracting a component of the R signal having high correlation with the L signal, subtracting the component from the L signal, thereby generating a first surround signal; and an SR signal generation section 30 and a BR signal generation section 50 as second surround signal generation units for extracting a component of the L signal having high correlation with the R signal, subtracting the component from the R signal, thereby generating a second surround signal.

Abstract: The designation of a localization position is received in accordance with an input position on a dashboard image in a localization-position reception window, and delay times for audio signals supplied to respective speakers are set so that the sound image is localized at the received localization position. The position where a sound image aurally perceived is localized is received, on the dashboard image in a localization-position confirmation window, from the user, until the user indicates that the position where the sound image aurally perceived is localized matches the localization position designated in the localization-position reception window. The relationship between the delay times and the localization position is re-estimated so as to correspond to the received localization position and the set delay times. In accordance with the estimated relationship, processing for re-setting the delay times is repeated.

Abstract: An array loudspeaker is constructed by stacking loudspeaker rows in a plurality of stages, each of the loudspeaker rows being formed by arranging loudspeaker elements in the form of a horizontal line. The loudspeaker rows are arranged in a zigzag form by, for example, offsetting the positions of the loudspeakers in the left and right direction for each stage. As for a high range signal, a two-stage portion of halves of the loudspeaker rows is used to narrow the pitch of the loudspeaker elements so as to prevent the grating lobe. As for a low range signal, the entire single-stage loudspeaker row is used to alleviate the deviation with respect to the directivity characteristics of the high range.

Abstract: An audio reproduction system comprises an arrangement of audio speakers (1-5) of a first kind having a first degree of directivity in combination with at least one audio speaker (7) of a second kind having a second degree of directivity. In order to create a virtual sound source at a desired distance to a listeners position (LP) the second degree of directivity is substantially larger than the first degree of directivity.

Abstract: Volume adjustment based on listener position is disclosed. A position of one or more speakers is identified, and a position of a listener is tracked. For each of the one or more speakers, a changing distance between that speaker and the listener is assessed. A volume of that speaker is automatically adjusted in real-time based on a current distance between that speaker and the listener.

Abstract: To provide a speaker array apparatus and a method for setting audio beams in a speaker array apparatus, in which the degree of freedom in the place where the speaker array apparatus is installed is high, and a user can set audio beams easily. A speaker array apparatus 1 sweeps a range of from 0 degree to 180 degrees in front of a speaker array 10 with audio beams based on an audio signal limited to a band where the angles of the audio beams can be adjusted. The speaker array apparatus 1 collects direct sounds or reflected sounds of the audio beams through a nondirectional microphone 2. The speaker array apparatus 1 analyzes the collected audio data, detects peaks not lower than a threshold value, and checks symmetry among the peaks. When there is a symmetry, the angles where the peaks were detected are set as angles with which audio beams of respective channels of a surround-sound should be output.

Abstract: A driver arrangement for a speaker array (201) comprises a first and second driver (301, 303) each arranged with an on-axis direction at an angle to an on-axis direction of the speaker array (201). The first driver angle exceeds 5° and the second driver angle exceeds the first angle. A front section of each driver (301, 303) comprises a front edge of a radiating element and parts of the driver in front thereof. The drivers (301, 303) are arranged at least partly inline such that a first distance from a front axis (311) perpendicular to an on-axis of the speaker array (201) and intersecting a furthest forwards part of the first driver front section to a closest part of the first driver front section is lower than a second distance from the front axis (311) to a furthest part of the second driver front section. The combination of angled drivers and the inline arrangement provides improved performance.

Abstract: Multi-channel audio signals arranged to achieve original two-dimensional sound image localization are input, and the audio signal of each channel, included in the input multi-channel audio signals, is distributed to individual output channels. Each of the distributed signals is multiplied by a corresponding coefficient determined independently for each of the output channels, in accordance with a deviation from the original two-dimensional sound image localization. Then, the audio signals distributed to the individual output channels and multiplied by the corresponding coefficients are summed up, separately for each of the output channels. Thus, the summed-up audio signals of the individual output channels are output as multi-channel audio signals having the sound image localization varied in accordance with the deviation. If the deviation from the original two-dimensional sound image localization is varied over time, a panning effect can be achieved.

Abstract: A system and method for performing efficient directed sound and/or data to a user utilizing position information. Various aspects may, for example, comprise determining position associated with one or more recipients of audio signals, determining one or more audio signal parameters based, at least in part, on such determined position information, and generating audio signals based on such determined audio signal parameters. For example, direction, timing, phasing and/or magnitude of such audio signals may be adapted based on a dynamic recipient positional environment.

Abstract: To realize virtual surround reproduction with small deterioration in the SN ratio of an entire reproduction system, in the case of adding together virtual surround signals and front-channel audio signals in an adder 1300, volume normalization is carried out in a volume normalizing section 1200 before the addition. In the case where the addition is not performed, the virtual surround signals and the front-channel audio signals are output independently of each other without being subjected to volume normalization in the volume normalizing section 1200.

Abstract: A loudspeaker input switch system for a truck cabin includes set of loudspeakers arranged in a perimeter arrangement, and an amplifier for amplifying signals from both a stereo player with a forward front-of-stage simulation, and a surround sound player with a front-of-stage simulation rotated 90° from the forward direction. A switching mechanism is used to selectively control the amplifier to change orientation of the front-of-stage simulation. A stereo music program can be played oriented correctly for a user driving the truck and a surround sound program can be played correctly oriented for a user turned 90° from the driving position.

Abstract: In a sound signal playback machine and method thereof, predetermined high frequency components are extracted from sound signals SL to SC of a main channel by high frequency pass filters 21 to 25, and these high frequency components are respectively played back by speakers. At the same time, predetermined low frequency components are extracted from sound signals SL to SC of the main channel by low frequency pass filters. These low frequency components and sound signal SLFE exclusively used for the low frequency band are added to each other, and the thus obtained addition signal is played back by the speaker 66. In this case, the degree of the low frequency pass filters is set higher than the degree of the high frequency pass filters, and the high frequency component is delayed.

Abstract: An integrated individual listening device and decoder for receiving an audio signal including a decoder for decoding the audio signal by separating the audio signal into a voice signal and a background signal, a first end-user adjustable amplifier coupled to the voice signal and amplifying the voice signal; a second end-user adjustable amplifier coupled to the background signal and amplifying the background signal; a summing amplifier coupled to outputs of said first and second end-user adjustable amplifiers and outputting a total audio signal, said total signal being coupled to an individual listening device.