Abstract: A new acoustic echo suppressor and method for acoustic echo suppression is described herein. Exemplary embodiments of the acoustic echo suppressor use one linear regression model for each subband. The linear regression model for each subband may operate on the squared magnitude of the input samples as well as corresponding cross-products. In this way, accurate and robust estimates of the echo signal in each subband can be obtained, thereby providing good echo reduction while keeping the signal distortion low.

Abstract: A method and apparatus of generating a sound field effect is provided. The sound field effect generating apparatus may generate a frequency coefficient that is frequency-transformed from a direct signal, may generate a reflection signal from the frequency coefficient, may generate an output signal using the frequency coefficient and the reflection signal, and may perform an inverse-frequency transform of the output signal.

Abstract: A surround experience for headphones can be created using various techniques and tools. The described techniques and tools can be applied separately or in combination. For example, a surround experience can be created by splitting input audio channel signals into high-pass and low-pass signals. The low-pass signals can undergo cross-mixing and artificial reverberation. The artificial reverberation can apply different delay profiles to the low-pass audio signals. The high-pass and low-pass audio signals can be combined to generate output audio channel signals. A surround experience can be crated using a system comprising an input module, a crossover module, a channel cross-mixing module, a reverberation module, and an adder module.

Abstract: A reverberation effect adding device comprising a first convolution circuit which in turn comprises FIR filters (80-1 to 80-4) and an adder (accumulator) (81) which adds outputs from the FIR filters, a moving average circuit (82) which receives musical sound waveform data delayed by a predetermined number of stages in the first convolution circuit and which outputs averaged second musical sound waveform data obtained by sampling at a second sampling frequency lower than the first sampling frequency, a second convolution circuit which in turn comprises FIR filters (80-5 to 80-28) which sequentially receive the second musical sound waveform data obtained by sampling at the second sampling frequency and an adder (accumulator) (83), an interpolator (84) which receives an output from the adder (83) of the second convolution circuit, calculates an interpolated value of the output value from the adder (83), and provides the output from the adder (83) and the interpolated value from the interpolator (84) sequentially

Abstract: A method and apparatus for processing sound sources to simulate environmental effects includes source channel blocks for each source and single reverberation block. The source channel blocks include direct, early reflection, and late reverberation blocks for conditioning the source feeds to include delays, spectral changes, and attenuations depending on the position, orientation and directivity of the sound sources, the position and orientation of the listener, and the position and sound transmission and reflection properties of obstacles and walls in a modeled environment. The outputs of the source channel blocks are combined and provided to single reverberation block generating both the early reflections and the late reverberation for all sound sources.

Abstract: An electronic circuit for adding the effects of reverberation to a high impedance signal produced from an external audio source such as a guitar pickup or a high impedance microphone.

Abstract: A data processing apparatus is designed for simulating an acoustic characteristic of an acoustic space which contains a sound source for generating a sound and a sound receiving point for receiving the sound. In the apparatus, each of a plurality of characteristic control sections processes sound data and outputs the processed sound data. The characteristic control sections correspond to transmission paths which must exist in the acoustic space such that the sound generated from the sound source travels to the sound receiving point through the respective transmission paths. An instruction section provides a processing instruction of the sound data to each characteristic control section such that each characteristic control section processes the sound data according to the provided processing instruction to thereby execute the simulation of the sound traveling through the corresponding transmission path.

Abstract: The present invention provides an apparatus and a method for emulating audio. The apparatus comprises an echo device, a reverberation device, an audio source device and a first signal synthesizer. Wherein, the echo device receives an audio source signals and applies thereof for generating echo signal and feedback signal; the reverberation device receives the audio source signal and applies thereof in accordance with the feedback signal of the echo device for generating a reverberation signal; the audio source device receives the audio source signal and applies thereof for outputting a direct audio source signal; and the first signal synthesizer is used to receive and synthesize the echo signal, the reverberation signal and the direct audio source signal so as to output a first synthesized signal, which is an audio effect emulation signal.

Abstract: The present invention is directed to creating sound reverberation. In accordance with a preferred embodiment, an apparatus estimates an impulse response for use in reproduction of a sound in a desired acoustic space. In particular, the apparatus collects space information concerning an acoustic space and point information indicating positions of a sound generation and reception points in the acoustic space, estimates a set of acoustic ray paths of the sound traveling from the sound generation point to the sound reception point, acquires directivity information indicating an acoustic directivity of the sound generation point and the sound reception point, estimates an acoustic intensity of each acoustic ray path and weights each acoustic intensity by the acquired directivity information, and determines the impulse response based on directions of the respective acoustic ray paths toward the sound reception point and the weighed acoustic intensities of the respective acoustic ray paths.

Abstract: In a reverberation apparatus, a storage section stores a directional characteristic representing a directivity of generated sound at a sound generating point. A position determining section determines a position of the sound generating point within an acoustic space on the basis of an instruction from the user. An orientation determining section determines an orientation of the sound generating point based on the determined position thereof. An impulse response determining section determines an impulse response for each of sound ray paths along which the sound emitted from the sound generating point travels to reach a sound receiving point, in accordance with the directional characteristic of the generated sound and the orientation of the sound generating point. A calculation section performs a convolution operation between the impulse response and an input audio signal so as to apply thereto the acoustic effect.

Abstract: Reverberation imparting functions as are obtained by a mechanical type reverberation apparatus employing coil spring delaying elements are simulated by an electric circuit configuration. Three delay loop circuits are individually provided, each including a first and a second delay circuit and delaying and circulating an input signal to thereby simulate the propagation of vibrations through each individual coil spring. Multiplier circuits are provided to individually supplying the out puts from the first and the second delay circuit in one delay loop circuit to the input sides of the second and the first delay circuit in two other delay loop circuits after controlling the signal characteristic to thereby simulate the propagation of vibrations through the supporting plates for the coil springs.

Abstract: A sound field effect adding apparatus is provided to add such effects as reverberation to the musical tone signal of an electronic organ and the like, and to produce a sound field effect. It is possible to create a satisfactory reproduced sound field to which a sound field effect has been added by means of a low frequency component without having to provide a dedicated unit or dedicated speaker system that can reproduce low frequencies. The apparatus has an input terminal with which a musical tone that includes a low frequency is input, and a means in which a sound field added musical tone signal is generated that produces a sound field effect that is based on an input musical tone signal.

Abstract: A music apparatus is constructed for introducing a music sound into an acoustic space, and is equipped with an acoustic feedback system for introducing a reflection sound into the acoustic space. In the music apparatus, an input device sequentially provides performance information. A sound source generates a music signal representative of the music sound in response to the performance information provided from the input device. A plurality of channels of the acoustic feedback system are provided in the music apparatus, and are spatially separate from each other.

Abstract: A digital wavetable audio synthesizer is described. The synthesizer can generate up to 32 high-quality audio digital signals or voices, including delay-based effects, at either a 44.1 KHz sample rate or at sample rates compatible with a prior art wavetable synthesizer. The synthesizer includes an address generator which has several modes of addressing wavetable data. The address generator's addressing rate controls the pitch of the synthesizer's output signal. The synthesizer performs a 10-bit interpolation, using the wavetable data addressed by the address generator, to interpolate additional data samples. When the address generator loops through a block of data, the signal path interpolates between the data at the end and start addresses of the block of data to prevent discontinuities in the generated signal. A synthesizer volume generator, which has several modes of controlling the volume, adds envelope, right offset, left offset, and effects volume to the data.

Abstract: A music sound correcting apparatus for correcting a music sound signal entered thereinto to selectively supply the corrected music sound signal to a speaker and a headphone, is provided with a jack into which a plug of the headphone is inserted, and a detector for detecting whether or not this plug of the headphone is inserted into the jack. When the detector detects that the plug is not inserted into the jack, a frequency of the entered music sound signal is changed so as to be properly reproduced by the speaker. On the other hand, when the detector detects that this plug is inserted into the jack, the entered music sound signal is corrected so as to be properly reproduced by the headphone in such a manner that a sound image produced based upon the entered music sound signal is localized to a predetermined position. As a result, preferable music sound can be reproduced even when the speaker is used and the headphone is employed irrespective of a small amount of hardware.

Abstract: A sound reproduction control apparatus processes an audio signal in reproduction of a musical sound to control a tone of the musical sound while imparting an effect to the musical sound. A preceding tone controller has a variable frequency response for amplifying the audio signal by the variable frequency response so as to variably control the tone of the musical sound. A signal processor is connected to the preceding tone controller for processing the audio signal to impart a desired effect to the musical sound. A succeeding tone controller is connected to the processor means and has an adjustable frequency response adjusted separately from the variable frequency response of the preceding tone controller for amplifying the audio signal by the adjusted frequency response so as to adjustively control the tone of the musical sound.

Abstract: A keyboard musical instrument produces electronic sounds in synchronism with fingering on a keyboard, and a player can select an reverberation emvironment and a depth of reverberation through predetermined keys of the keyboard before the performance, thereby making an arrangement on a switch board simpler.

Abstract: An echo generating apparatus includes an echo effect generator for producing reverberative echo effect by delaying an input audio signal; a band limit filter for limiting the frequency band of the output signal of the echo effect generator; a first calculator for delivering an output signal by calculating the input audio signal and the output signal of the band limit filter; and a frequency characteristic compensator for emphasizing the signal of the frequency band attenuated by the band limit filters. The echo effect generator consists of a second calculator for calculating the input audio signal and the output signal of the band limit filter, an analog delay means for delaying the output signal of the second calculator, and a clock generator for generating an operation clock signal for the analog delay means. A long reverberative echo time is maintained without the necessity of increasing the number of signal delay stages or enlarging the scale thereof.

Abstract: An electronic musical instrument changes sound effects, such as resonance and reverberation, during a performance. The instrument has a tone-ON channel counter, for counting keys that are simultaneously depressed; an output channel determination unit, for determining an output channel in consonance with a count value held by the tone-ON channel counter; and an output channel selector, for designating the output channel, so as to provide a desired sound effect through the selected output channel.In a modification, the instrument has a parameter value determination unit, for determining a parameter value in consonance with a count value counted by the tone-ON channel counter; a resonant tone production unit, for adding a desired sound effect; and a controller, for employing the parameter value to control the resonant tone production unit.

Abstract: A sound echo machine as an acoustic signal processing unit of the present invention comprising an adder to which an input signal is fed, and a delay circuit for delaying the signal fed from the adder for a certain time to repeatedly feed back to the adder to generate an echo sound further comprises an input signal level detector for detecting the level of the input signal and sending it to a frequency oscillator to vary the oscillating frequency in accordance with the thus detected signal level for feeding it later to the delay circuit so as to modulate the time to be delayed at a predetermined cycle, whereby it can create an acoustic field in which a listener can feel as if various level of reflected sounds are coming towards him from various directions.

Abstract: A sound effect-creating device for imparting a sound effect to a musical tone produced by performance subjects an analog or digital signal indicative of the musical tone to reverberation processing over a predetermined reverberation time to add reverberations to the musical tone. The predetermined reverberation time is set based on a basic reverberation time determined in a manner dependent on the repetition period of a timing clock of a MIDI signal received from an external electronic musical instrument. Alternatively, the repetition period of a timing clock of a MIDI signal transmitted to an external electronic musical instrument is determined based on a reverberation time parameter used in setting the predetermined reverberation time.

Abstract: A preamplifier device employing electron tubes wherein the preamplifier has tremolo/vibrato circuits independent from reverb circuits allowing continuously variable control of either tremolo or vibrato effects simultaneous with continuously variable control of the reverb effect. A mixer control for controlling the level of reverb and a tone control is provided. Connections are provided for external switches used to disable any one of the above effects.

Abstract: A nonlinear function generation apparatus and a musical tone synthesis apparatus are disclosed.The nonlinear function generation apparatus comprises hysteresis and nonhysteresis function generators for generating hysteresis and nonhysteresis functions using an input signal as a variable respectively, and a multiplier for synthesizing the functions outputted from the generators.The musical tone synthesis apparatus comprises a closed loop including delay circuits, and the nonlinear function generation apparatus.

Abstract: An electroacoustic system for acoustic enhancement of a room that includes a sound source location. The electroacoustic system includes a microphone spaced from the sound source location, an array of loudspeakers arranged in at least four interleaved banks, each bank including at least one loudspeaker, and signal processing electronics connected between the microphone and the speaker banks that includes an input channel, circuitry connecting the microphone to the input channel, a plurality of output channels corresponding in number to the number of speaker banks, circuitry connecting each output channel to a corresponding speaker bank, and at least four statistically independent time-variant reverberation units responsive to input signals from the microphone for producing output signals on the output channels for driving the several banks of speakers.

Abstract: An apparatus for producing an improved sound field in an acoustic space. The apparatus comprises a signal source for producing a source signal. The source signal is applied to a loudspeaker for reproduction thereof. The source signal is also applied to a reverberation circuit. The reverberation circuit includes at least two reverberation signal generators which provide different predetermined time delays to the source signal for converting it to two reverberation signals. At least one phase inverter is connected to invert at least one of the two reverberation signals before the reverberation signals are reproduced.

Abstract: A reverberation circuit comprises an amplifier, attenuation circuit, a feedback component, and a delay circuit. The amplifier, delay circuit, and feedback component form a feedback loop. The amplifier amplifies an input signal supplied to an input terminal and outputs an amplified signal to the delay circuit. The output of the delay circuit is fed through a feedback component back to the amplifier. The feedback component controllably varies the feedback amount of the delayed signal to the amplifier in accordance with the desired depth of reverberation. An attenuation circuit is placed in the feedback loop, or before or after the feedback loop. The attenuation circuit selectively attenuates the level of specific frequency component of a signal passing therethrough whose frequency may be different depending on the depth of reverberation or feedback amount.

Abstract: Disclosed is a signal processor formed using digital waveguide networks. The digital waveguide networks have signal scattering junctions. A junction connects two waveguide sections together or terminates a waveguide. The junctions are constructed from conventional digital components such as multipliers, adders, and delay elements. The signal processor of the present invention is typically used for digital reverberation and for synthesis of reed, string or other instruments.

Abstract: An audio signal processing apparatus for digitally processing input audio signals according to the contents of a program for creating a given sound field. A basic program for creating a specific sound field is read from a first memory. The contents of the basic program are modified as required. The modified program is assigned thereto information identifying the basic program. The modified program as well as the identification information is stored in a second memory. When the modified program is read from the second memory, the information identifying that program is displayed first. After a predetermined time, the information identifying the basic program on which the modified program is based is displayed, replacing the previously displayed identification information.

Abstract: An electronic musical instrument for causing a tone generator to generate a musical tone corresponding to a musical performance while controlling an envelope by operation of a pedal. An operated-amount signal generator is provided for detecting an operated amount of the pedal and for generating an operated-amount signal, and an effect adding unit is provided for controlling parameters for effect addition so as to add an effect to a musical tone generated from the musical tone generator in accordance with the operated-amount signal from the operated-amount signal generator. The operated-amount signal from the operated-amount signal generator is changed by the operation of the pedal, and an effect-adding parameter in the effect adding unit is changed accordingly, to thereby add an effect to the generated musical tone.