Abstract: Multi-channel headphones capable of providing quality 3-dimensional (3-D) sound in an atmosphere of intimacy and privacy for individuals is provided. The multi-channel headphones ensure high-quality 3-D sound reproduction with accurate phase using distinct speaker units for multiple channels. The multi-channel headphones includes at least two speaker units for each ear piece, each for generating distinct sounds from multiple channels; and at least two enclosures in each of which each of the at least two speaker units arc installed. The multi-channel headphones include a sound guide portion in each of the enclosures to guide the sound emanating from the corresponding speaker unit into the listener's ear. A diffraction effect of the sound from the rear speaker can be induced.

Abstract: An audio device comprising a casing containing a circuit and a spool rotatable about an axis, two earpieces connected by lead wires,

Abstract: The present invention relates to a sound image localizing apparatus for generating a sound image localized in an arbitrarily set three-dimensional direction. The sound image direction setting unit (111) is operable to set a three-dimensional direction to which the sound image is to be localized in accordance with a listener's instruction; the angle conversion unit (112) is operable to convert the direction into a lateral angle (&agr;) and a rising angle (&bgr;), each of which serves as a cue for the listener to perceive the direction. The convolution operation unit 116 is operable to obtain lateral angle control information corresponding to the lateral angle (&agr;) from the lateral angle control information storage unit (113), a listener's front direction head-related impulse response from the front direction head-related impulse response storage unit (115), and rising angle difference information corresponding to the rising angle (&bgr;) from the rising angle difference information storage unit (114).

Abstract: A headphone accessory such as an outer casing for use in combination with a headphone system, which makes the headphone system more comfortable to wear, and serves various function suitable for long time wearing. The headphone accessory includes a sound field-forming member having a cylindrical part, which supports speaker units for reproducing sound from electrical signals or supports enclosures in which the speaker units are mounted, surrounds listener's ears and forms a space in which sound output from the speaker units or enclosures are collected into the listener's ears, and an outer casing formed of an elastic material, which can be separated from the circumference of the cylindrical part of the sound field-forming member and is directly in contact with the side of a listener's head around the ears.

Abstract: The invention relates to a method for converting signals in two-channel stereo format to become suitable to be played back using headphones. The invention also relates to a signal processing device for carrying out said method. According to the invention left direct path (Ld) and left cross-talk path (LX) signals are formed from the left input signal (Lin), and correspondingly right direct path (Rd) and right cross-talk path (RX) signals are formed from the right input signal (Rin), and further the left output signal (Lout) is formed by combining said left direct-path (Ld) and said right cross-talk path (Rx) signals, and correspondingly, the right output signal (Rout) is formed by combining said right direct-path (Rd) and said left cross-talk path (Lx) signals.

Abstract: A method of customizing the HRTF for each tested individual for providing all tested individuals an optimum audio experience by providing convincing and realistic three-dimensional sounds. Customization can be achieved by playing a series of sample sounds and having the tested individual locate where the sound is emanating from. In this way, the method can identify for each test subject which audible positional cues are most important, how frequency changes are interpreted as position, and what effects are most convincing and pleasurable. This information is used to effect the HRTF for each tested individual. The customized HRTF will then be applied to all three-dimensional sounds giving the listener an optimum audio experience.

Abstract: The invention relates to a method of generating a left modified and a right modified audio signal for a stereo system from multichannel audio signals (XL, XR, XLS, XRS, and XC) with a left and a right channel and at least one further audio channel. According to the invention, the signal of the channel of highest energy is modified in a filter (1) with a transformation function in a first parallel branch (2) and is modified in a second filter (6) with a reverberation function in a second parallel branch (5), whereupon the modified signals are joined together in a summation unit (8).

Abstract: The invention provides a method for simulating a 3D sound environment in an audio system using an at least two-channel reproduction device, the method including generating first and second pseudo head-related transfer function (HRTF) data, first using at least one speaker and then using headphones; dividing the first and second frequency representation of the data or using a deconvolution operator on the time domain representation of the first and second data, or subtracting the cepstrum representation of the first and second data, and using the results of the division or subtraction to prepare filters having an impulse response operable to initiate natural sounds of a remote speaker for preparing at least two filters connectable to the system in the audio path from an audio source to sound reproduction devices to be used by a listener.

Abstract: The invention relates to a method, signal processing device and computer program for stereo widening (SW) of stereo format signals to become suitable for headphone listening. The invention also relates to a mobile appliance performing signal processing according to the invention. According to the invention a separate monophonic signal path (ME) is formed in order to equalize the frequency spectrum of the monophonic component of the left and right output signals (Lout,Rout) by at least extracting from the left and right input signals (Lin,Rin) an at least substantially monophonic signal component contained in said signals (Lin,Rin), processing the extracted monophonic signal component to obtain a processed monophonic signal component, and combining said processed monophonic signal component with at least one of the left (Lout) or the right (Rout) output signals.

Abstract: In views of a disadvantage that in a conventional method for localization of sound image in stereo listening, the amount of software is increased and the scale of hardware is enlarged, this invention has been achieved to solve such a problem and intends to provide a processing method for audio signal to be inputted from an appropriate sound source capable of higher precision localization of sound image than the conventional method. When a sound generated from an appropriate sound source SS is processed as an audio signal in the order of inputs on time series, the inputted audio signal is transformed into audio signals for the left and right ears of a person and further each of the audio signals is divided to at least two frequency bands.

Abstract: A multi-channel earphone module is provided. The earphone module comprises two earphone units for engaging with each respective ear of a user. Each earphone unit includes a housing, a front channel speaker, a rear channel speaker and a subwoofer channel speaker. The front and the back channel speaker are adjacent to each other within the housing. The subwoofer channel speaker is installed at the bottom of the housing. The axis of the front channel speaker and the axis of the rear channel speaker form an acute angle for reducing the overlapping or interference of acoustic sound waves and improving output sound quality.

Abstract: A method of processing a series of input audio signals representing a series of virtual audio sound sources placed at predetermined positions around a listener to produce a reduced set of audio output signals for playback over speaker devices placed around a listener, the method comprising the steps of: (a) for each of the input audio signals and for each of the audio output signals: (i) convolving the input audio signals with an initial head portion of a corresponding impulse response mapping substantially the initial sound and early reflections for an impulse response of a corresponding virtual audio source to a corresponding speaker device so as to form a series of initial responses; (b) for each of the input audio signals and for each of the audio output signals: (i) forming a combined mix from the audio input signals; and (ii) forming a combined convolution tail from the tails of the corresponding impulse responses; (iii) convolving the combined mix with the combined convolution tail to form a combined t

Abstract: Head Related Transfer Functions (HRTFs) of an individual are measured in rapid fashion in an arrangement where a sound source is positioned in the individual's ear channel, while microphones are arranged in the microphone array enveloping the individual's head. The pressure waves generated by the sounds emanating from the sound source reach the microphones and are converted into corresponding electrical signals which are further processed in a processing system to extract HRTFs, which may then be used to synthesize a spatial audio scene. The acoustic field generated by the sounds from the sound source can be evaluated at any desired point inside or outside the microphone array.

Abstract: This invention may provide a headphone driving circuit needless of coupling condenser even if the power supply supplies a single output voltage. The headphone driving circuit comprises (1) a first amplifier to amplify a first composite signal generated by subtracting a second channel audio signal from a first channel audio signal, then driving one end of a first voice coil of a stereo-headphone, (2) a second amplifier to amplify a second composite signal generated by subtracting the first channel audio signal from the second channel audio signal, then driving one end of a second voice coil of the stereo-headphone, (3) a third amplifier to amplify a third composite signal generated by adding the first channel audio signal and the second channel audio signal for driving the other end of the first and the second voice coil of the stereo-headphone.

Abstract: A method for creating a multichannel audio signal that provides the impression of spatial sound is disclosed, the method comprising providing an expected multichannel audio output signal having spatialised soundfield components; perturbing the spatial components; and utilising the perturbed spatial components to determine the multichannel audio signal. The perturbations can be substantially in accordance with the expected head movements of listeners of the audio signal and can be derived from a group of listeners to the audio signal. The expected head movements also preferable include an added substantially random movement.

Abstract: The invention relates to an audio reproducing apparatus having a converting means for converting main audio signals included in an audio signal for a plurality of channels into audio signals that provide a reproduction sound field similar to that obtained in reproduction by means of speakers even when the audio signals are reproduced by means of headphones; and an adding means for adding an auxiliary audio signal included in the audio signal for a plurality of channels to an audio signal outputted from the converting means; wherein an audio signal outputted from the adding means is supplied to headphones.

Abstract: A headphone unit having left and right ear piece units and an input cord having two conductors an end of each of which projects into a housing. Within the housing, the input cord is connected to two equipment cords which terminate in a pair of input plugs. Each of the equipment cords has two lines. The input plugs each have portions for receiving left and right audio signals. The lines carrying left audio signals from the two input plugs are connected to the input cord conductor which leads to the left ear piece unit and the lines carrying right audio signals from the two input plugs is connected to the input cord conductor which leads to the right ear piece unit.

Abstract: An acoustic image localization signal processing device capable of localizing an acoustic image in an arbitrary direction by means of a simple configuration includes: a sound source data storage unit 1, which stores second sound source data obtained by subjecting first sound source data to signal preprocessing in advance such that the acoustic image is localized in a predetermined direction; and, an acoustic image localization characteristic application processing unit 2, which applies an acoustic image localization position characteristic, based on position information from an acoustic image control input unit 4, to the second sound source data, when the second sound source data are read from the sound source data storage unit 1 and reproduced by headphones 7R, 7L. Accordingly, the acoustic image localization position of the reproduced output signals D1, D2 resulting from the second sound source data is controlled.

Abstract: System for producing multi-dimensional sound to be heard by an aircraft crew member, the multi-dimensional sound being respective of an input signal received from a source and associated with a respective indicated input signal position, the system comprising an aircraft crew member position system, detecting the aircraft crew member position, a memory unit, storing a plurality of spatial sound models, a processor, coupled with the aircraft crew member position system, the memory unit and with the source, the processor retrieving a selected one of the spatial sound models from the memory unit, according to the indicated input signal position and the aircraft crew member position, the processor applying the selected spatial sound model to an audio signal respective of the input signal, thereby producing a plurality of audio channels, and a plurality of head-mounted sound reproducers, coupled with the processor, each the head-mounted sound reproducers being associated with and producing sound according to a res

Abstract: An audio output apparatus comprises a sound output unit configured to output sound that corresponds to the audio data transmitted from a first sound source device connected by radio to the audio output apparatus, a priority-level comparing unit configured to compare priority information transmitted from the first sound source device and representing a priority level assigned thereto, with priority information transmitted from a second sound source device and representing a priority level assigned thereto, when the second sound source devices is connected by radio to the audio output apparatus while the audio output apparatus is outputting sound corresponding to the audio data transmitted from the first sound source device, and a sound-source selecting unit configured to select one of the first and second sound source devices, as a source of sound to be output, in accordance with the result of comparison performed by the priority-level comparing unit.

Abstract: The invention relates to a headphone with one right housing and one left housing, which are associated with a user's ears. These housings are provided-with acoustic baffles in which there. are disposed dynamic sound transducers, each of which comprises a tweeter and a mid/woofer disposed coaxially therewith. To ensure that the localization of auditory events reproduced by this headphone can be controlled selectively, the acoustic baffle in each housing is provided with a first high damping portion which, relative to the center of the sound transducer, covers a region of more than 170 degrees and less than 340 degrees of the mid/woofer. The remaining region is a cutout for the tweeter and leaves uncovered a substantially V-shaped region with an apex angle of smaller than 170 degrees and larger than 20 degrees. There is also a second high damping portion, which is disposed in the region of the apex of the V-shaped region which leaves between 5% and 50% of the tweeter covered.

Abstract: In an audio reproducing apparatus, first and second filters convolute impulse responses corresponding to transfer functions from a position where a right-hand sound source is located to the right and left ears of the listener into an audio signal, respectively, and third and fourth filters convolute impulse responses corresponding to transfer functions from a position where a left-hand sound source is located to the right and left ears of the listener into another audio signal, respectively. Fifth and sixth filters extract low-frequency components of the audio signal, and seventh and eighth filters extract low-frequency components of the another audio signal. The output signals of the first, third, fifth, and seventh filters are added, and the output signals of the second, fourth, the sixth, and eighth filters are added.

Abstract: A headphone/earmuff includes a headband, a pair of ear cups and associated positioning devices attaching each ear cup to the headband. Each ear cup positioning device has a cylinder attached to either the ear cup or the headband, and a piston received slidably within the cylinder and attached to the other of the headband or the ear cup.

Abstract: In a playback apparatus formed by a playback apparatus main body and wireless headphone, music data is read out from a recording medium, is decoded by a decoder, and the decoded music data is transmitted from a digital wireless transmitter to the headphone in the form of digital data in the playback apparatus main body. In the wireless headphone, the music data transmitted from the playback apparatus main body is received by a digital wireless receiver, the received music data is temporarily saved in a buffer memory, the saved music data is read out from the buffer memory, the readout data is converted by a D/A converter from digital data into an analog signal, and the analog signal is converted into sound via loudspeakers.

Abstract: A stereo sound expander reproduces a realistic sound image in three dimensions by coupling modified and unmodified stereo signals. By not modifying a Head Related Transfer Function (HRTF) for one signal and equalizing the HRTF for the other signal, a flattened frequency response is produced with no tonal changes, but with a high degree of spatial accuracy. Resultant output signals may be used to generate binaural signals or can be fed into crosstalk cancellers.

Abstract: A system is disclosed for steering a monaural audio signal representing a source of sound into left and right audio signals for presentation to the corresponding ears of a listener so that the listener perceives the sound source in a specific location relative to his head. The left and right signals may be provided through headphones or loudspeakers, in the latter case employing techniques to cancel the crosstalk from each loudspeaker into the opposite ear of the listener. The monaural audio signal is filtered using head-related transfer functions (HRTFs) into the left and right outputs, these being equivalent to the acoustic HRTFs that would be generated if a source of sound were placed at the specific location relative to the listener.

Abstract: Face of a listener (user) is photographed by a CCD camera, and a face width and auricle size of the listener are detected on the basis of the picture of the listener's face. Head-related transfer functions, which are transfer functions of sounds propagated from virtual rear loudspeakers to both ears of the listener, are calculated, using the detected face width and auricle size as head shape data of the listener. Then, a filter process is performed by a DSP of a USB amplifier unit so as to attain characteristics of the head-related transfer functions, as a result of which sound image localization of the rear loudspeakers can be achieved via front loudspeakers.

Abstract: In correspondence with the left and right external ears of a listener occupying a seat, a three dimensional sound field reproducing unit includes at least more than two speakers disposed on a headrest on the top of a backrest of the seat, and three dimensional signal processing means which converts an output signal from a sound source into a three dimensional sound field signal for supplying it to each of the speakers. Three dimensional sound field with high accuracy and fidelity is reproduced near the external ears of the listener.

Abstract: A system for customising the synthesis and generation of spatial hearing in virtual auditory space (VAS) for individual listeners includes a measuring ruler (12) and a digital processing unit (DPU) (14) to which the ruler (12) is connected. The ruler (12) is used for measuring various physical dimensions of the morphology of a person's external auditory periphery (16). The ruler (12) comprises a base (18) insertable into an ear canal (20) of the person's ear. A robotic measuring arm (22) extends from the base (18) and has a measuring tip (24) to enable the ruler (12) to record the Cartesian (x,y,z) coordinates of the tip (24) relative to the base (18). By suitable manipulation of the robotic arm (22), the tip (24) can be positioned at desired locations on the person's external auditory periphery (16) to enable the morphological measurements of the person's external auditory periphery (16) to be effected.

Abstract: The invention relates to a method of deriving a head-related transfer function within a room. According to the invention, electrical signals of a sound pattern or music signals are supplied to a speaker, and sound waves are emitted from the speaker. The sound waves and sound waves reflected within the room act on a speaker of a headset and are converted by the headset speaker into electrical signals. Then an associated head related transfer function is derived from the electrical signals and stored. When headsets are used as microphones in a calibration mode, HRTFs can be assessed without inserting microphones into a listener's cars. Calibration by the end user is thus simplified.

Abstract: A vehicle-mounted three dimensional sound signal reproducing-silencing unit includes at least two speakers disposed for each of seats to be occupied by listeners so as to generate a three dimensional sound field space in a region inclusive of left and right external ears of each of the listeners, and three dimensional signal processing means for converting an output signal from a sound source into a three dimensional sound field signal for supplying it to each of the speakers, thereby reproducing a three dimensional sound field with rich presence for each of the seats. The unit also includes antiphase signal generating means for supplying a silencing signal to the three dimensional signal processing means, thereby silencing sounds for each of the seats without giving an effect on the other seats.

Abstract: The present invention relates to a headphone with two ear cups each of which includes a loudspeaker or a plurality of multichannel speakers. Each speaker has its own individual sound chamber. In accordance with the feature of the speakers, they are installed at the front or rear sides of the individual sound chambers. Accordingly, each speaker is arranged inside the ear cup at different places or angles, thereby creating a clear sound field, protecting against the mixture of the sound waves and reducing the distortion. Beside, a well-distributed sound pressure is formed inside each individual sound chamber. Again, the surround sound effect is enhanced to achieve the original sound quality with high fidelity.

Abstract: An earphone-based voice transmission device. An earplug is placed inside a user's ear for collecting the voice generated by the eardrum. The voice is converted into an output electronic audio signal by a converter. Then, the output electronic audio signal is amplified and transmitted to a communication device for further transmission.

Abstract: A method of performing sound effect comprising providing a headphone-like or earphone-like device with rear speakers carried therein, wherein the headphone-like or earphone-like device includes an opening for receiving the front speaker signal. Then, the signal is transmitted to the front, rear and sub-woofer signal to associated speakers. The signal to the rear speakers is processed by HRTF and means for creating virtual speakers to obtain virtual speakers of the rear side. The processed signal is transmitted to the rear speaker.

Abstract: A supra aural headphone including an earphone that includes a shell body, a cushion mounted on the shell to thereby define an internal cavity behind the cushion, and an acoustical driver mounted within the internal cavity to reproduce sound for the user when driven by an audio signal. The cushion has a passageway extending therethrough which acoustically connects the internal cavity with a user's ear cavity when the cushion is resting on the user's ear while being worn by the user. The internal cavity has a total volume that is larger than about 10 cubic centimeters, and the driver is mounted in such a way as to avoid obstructing the passageway.

Abstract: Input digital sound signals are subjected to filtering for convolution of respective impulse responses, and resulting signals are supplied to time delay setting circuits. In each of the time delay setting circuits, output signals from adjacent two stages of delay circuits, which correspond to a direction closest to the detected facing direction of a listener are taken out as pairs of signals L2a, L2b, R2a and R2b. In crossfade processing circuits, each paired signals (L2a and L2b or R2a and R2b) are added at a proportion depending on the detected facing direction of the listener. Output signals of the crossfade processing circuits are taken out through correction filters for compensating frequency characteristic changes in a high frequency range. As a result, when listening to sound with headphones and localizing a sound image at an arbitrary fixed position outside the listener's head, shock noises generated upon change in the facing direction of the listener are reduced.

Abstract: An integrated personal audio device that provides hearing protection is disclosed. The device includes a flexible band configured to extend at least partially around a head of a user. An audio transmitter is coupled to the band. The band has two legs that terminate at respective end portions. Each end portion is coupled to an audio speaker, which is electrically connected to the audio transmitter. A hearing protector is mounted onto each respective audio speaker. Each hearing protector has a sound channel configured to transmit sound from the respective audio speaker to the user's ear. The sound channel may comprise a Venturi-shaped chamber. The sound channel may, for instance, include: (1) a sound-expansion-chamber portion; (2) a central-chamber portion having a smaller diameter than the sound-expansion-chamber portion; and (3) an end-chamber portion having a larger diameter than the central-chamber portion.

Abstract: A method and apparatus for producing virtual sound sources that are externally perceived and positioned at any orientation in azimuth and elevation from a listener is described. In this system, a set of speakers is mounted in a location near the temple of a listener's head, such for example, on an eyeglass frame or inside a helmet, rather than in earphones. A head tracking system determines the location and orientation of the listener's head and provides the measurements to a computer which processes audio signals, from a audio source, in conjunction with a head related transfer function (HRTF) filter to produce spatialized audio. The HRTF filter maintains the virtual location of the audio signals/sound, thus allowing the listener to change locations and head orientation without degradation of the audio signal. The audio system of the present invention produces virtual sound sources that are externally perceived and positioned at any desired orientation in azimuth and elevation from the listener.

Abstract: A sound processing system reduces speaker distortion at high volume levels by attenuating the filter gain and/or tone of audio and mixed output signals. The sound processing system has one or more filters to attenuate the filter gain and tone in response to the high volume levels. The sound processing system also can attenuate the filter gain and tone in response to a sound pressure level, which may be provided by a microphone.

Abstract: The Swimmer's Ear is an electronic device that allows a swimmer or bather a means to safely listen to music while engaged in water activities. This invention is unique in that it allows universal use of any existing electronic devices equipped with a headphone jack. The two part Swimmer's Ear will attach itself via a headphone jack to an existing electronic device such as a CD or MP3 player and transmit to the listener the music or sound. The receiver will be powered by a power source inside a waterproof housing. This receiver will allow the listener to attach it to one's head by means of a clip for any swimming goggles or headband The materials used for this invention are currently in use such as: durable plastics, radio frequency transmitter and receiver, waterproof housings.

Abstract: A method of synthesizing an audio signal having left and right channels corresponding to an extended virtual sound source at a given apparent location in space relative to a preferred position of a listener in use is described. The information in the channels includes cues for perception of the direction of said virtual sound source from the preferred position. The extended source comprises a plurality of point virtual sources, the sound from each point source being spatially related to the sound from the other point sources, such that sound appears to be emnitted from an extended region of space. If the signal from two sound sources is the same, they are modified to be sufficiently different from one another to be separately distinguishable by a listener when they are disposed symmetrically on either side of the listener. This modification can be accomplished by filtering the two point sources using different comb filters.

Abstract: A headset device is provided with a headphone unit having head band, a pair of guide arms and a speaker unit, a microphone unit connected to one side of the speaker unit, and a controller divided into two bodies, wherein since the pair of guide arms are adapted to be rotatably connected to the speaker unit, a position of the head band can be easily adjusted, with an auricle of the user being enclosed by the speaker unit, whereby the user can feel good to wear the headset device due to resilience and softness thereof, and wherein the headset device is capable of being used with various apparatuses such as a telephone and a computer system since the controller which can be divided into two bodies or assembled into a unit enables replacing connection terminals with various kinds of other connection terminals is used.

Abstract: The apparent location of sound signals as perceived by a person listening to the sound signals over headphones can be positioned or moved in azimuth, elevation and range by a range control block and a location control block. Several range control blocks and location control blocks can be provided depending on the number of input sound signals to be positioned or moved. All of the range and location control is provided by the range control blocks and location control blocks so that the resultant signals require only a fixed number of filters regardless of the number of input audio signals to provide the signal processing. Such signal processing resulting in accurate positioning and moving of the sound source is accomplished using front and back early reflection filters, left and right reverberation filters, front and back azimuth placement filters having a head related transfer function, and up and down elevation placement filters.

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: A hands-free headset includes first and second earpieces and is configured such that the second earpiece is integrally mounted to and stowed against the first earpiece during mono-communications operation or during storage. The headset includes two retractable cords which engage with a portable communications device. A sliding grommet attached to the retractable cords controls the separation of the cords and facilitates the two cords being reeled into a common cord reel. The headset also includes a switch which directs the desired electrical path to either stereo listening or communications operation. The headset further includes a docking platform which can be attached to the body of the portable communications device for storage and which holds the integral mounted earpieces against the cord storage reel for an aesthetic stowed hands-free device.

Abstract: The invention relates to a method for converting signals in two-channel stereo format to become suitable to be played back using headphones. The invention also relates to a signal processing device for carrying out said method. According to the invention left direct path (Ld) and left cross-talk path (LX) signals are formed from the left input signal (Lin), and correspondingly right direct path (Rd) and right cross-talk path (RX) signals are formed from the right input signal (Rin), and further the left output signal (Lout) is formed by combining said left direct-path (Ld) and said right cross-talk path (Rx) signals, and correspondingly, the right output signal (Rout) is formed by combining said right direct-path (Rd) and said left cross-talk path (Lx) signals.

Abstract: A headphone system that including casings that each contain at least two speakers. Each speaker in each casing is able to produce sounds of different frequencies and/or coming from separate channels. The headphone set may include an electrical device for separating one or more individual signals into two or more signals. The electrical device may be located directly on the headset.

Abstract: The invention relates to a system for generating sounds with a left front loudspeaker which converts an electric signal of a left audio channel and with a right front loudspeaker which converts an electric signal of a right audio channel. Such a system for generating sounds in a room is known. The electric signals are processed such that spatial rear loudspeakers are dispensed with and the front loudspeakers generate a surround or spatial sound. According to the invention, a virtual filter generates virtual sound bodies laterally of a listener in a region between 80 and 100 degrees. Experiments have shown that the human ear is most sensitive to surrounding sound when sound sources are arranged laterally of a listener's head or when spatial sound is generated laterally of a listener.

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: The present invention disclosed and claimed herein, in one aspect thereof, comprises a method for enhancing the front sound image during reproduction in a listening space of a stereo sound program, comprising the steps of receiving left and right channels of the stereo sound program; generating a virtual center channel signal from the left and right channels of the stereo sound program; and driving a center channel speaker with the virtual center channel signal, the center channel speaker disposed at a central location in a front portion of the listening space.