Filtering Patents (Class 84/661)
  • Patent number: 6111181
    Abstract: A synthesis of percussion musical instruments sounds is provided using a microprocessor (17) that implements an all pole lattice filter and applying either a single impulse signal to the filter or N samples of an excitation signal sequence to the filter by a memory (19). The coefficients of the filter are determined by storing digital samples (501) of desired musical note from a desired percussion instrument, generating a Fourier transform to get a spectrum (502), picking the peaks of the spectrum (503) to select the most prominent components in the spectrum and determining wanted frequencies for decaying sine waves and for the frequencies finding the time envelope and estimating therefrom the pole radius.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: August 29, 2000
    Assignee: Texas Instruments Incorporated
    Inventors: Michael W. Macon, Wai-Ming Lai, Alan V. McCree, Vishu R. Viswanathan
  • Patent number: 6101469
    Abstract: For use in a synthesizer having a wave source that produces a periodic wave, frequency shifting circuitry for frequency-shifting the periodic wave and waveshaping circuitry for transforming the periodic wave into a waveform containing a formant, the frequency-shifting causing displacement of the formant, a circuit for, and method of, compensating for the displacement and a synthesizer employing the circuit or the method. In one embodiment, the circuit includes bias circuitry, coupled to the wave source and the frequency shifting circuitry, that introduces a bias into the periodic wave based on a degree to which the frequency shifting circuitry frequency shifts the periodic wave, the bias reducing a degree to which the formant is correspondingly frequency-shifted.
    Type: Grant
    Filed: March 2, 1998
    Date of Patent: August 8, 2000
    Assignee: Lucent Technologies Inc.
    Inventor: Steven D. Curtin
  • Patent number: 6040516
    Abstract: There are provided a tone generator system using computer software and a storage medium storing the computer software. A musical tone synthesis module generates a musical tone signal by generating an excitation signal in response to an request for generating the excitation signal and at least delaying and looping the generated excitation signal. A first monitoring module monitors whether or not the request for generating the excitation signal is issued. A second monitoring module monitors whether or not the musical tone signal is generated by the musical tone synthesis module. An interruption module interrupts execution of the musical tone synthesis module when the first monitoring module detects that the request for generating the excitation signal is not issued, and at the same time the second monitoring module detects that the musical tone signal is not generated.
    Type: Grant
    Filed: March 30, 1999
    Date of Patent: March 21, 2000
    Assignee: Yamaha Corporation
    Inventor: Hideyuki Masuda
  • Patent number: 5998726
    Abstract: A musical sound generating system which generates musical sounds having desired tone regardless of the variation of volume setting. In the musical sound generating system, the standard tone control touch curve TCstd, the maximum tone control touch curve Tcmax, and the minimum tone control touch curve TCmin when the amplification factor V is standard (a standard amplification factor Vstd), maximum, and minimum respectively are stored. If the amplification factor is higher than the standard amplification factor Vstd, an interpolation between the standard tone control touch curve TCstd and the maximum tone control touch curve TCmax is performed, and the tone control touch curve TC according to the amplification factor V is obtained. Based on the tone control touch curve, the cut-off frequency F corresponding to the velocity value Tv is determined, and then the tone of the musical sound is controlled by the low pass filter with the cut-off frequency F.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: December 7, 1999
    Assignee: Kabushiki Kaisha Kawai Gakki
    Inventor: Jiro Tanaka
  • Patent number: 5945621
    Abstract: In a musical tone control apparatus, musical tones to be generated are controlled according to musical tone control parameters which include an envelope that has been extracted and processed. The range of variation of the extracted envelope may be limited within a predetermined range, so that the musical tones are controlled according to the thus limited envelope. A key-on event of the input signal may be detected, and the timing of delivery of the processed envelope may be changed according to a length of time that elapses from a point of time when the key-on event is detected. The velocity of the input signal may also be detected, so that the musical tones are controlled according to the musical tone control parameters including one or more parameters altered according to the detected velocity and processed envelope.
    Type: Grant
    Filed: September 20, 1996
    Date of Patent: August 31, 1999
    Assignee: Yamaha Corporation
    Inventor: Susumu Ishibashi
  • Patent number: 5942708
    Abstract: A music apparatus has a set of controls manually operable to input a performance event, a waveform memory storing an original waveform sample composed of a series of digital values sequentially readable from a default start address, and a processor for executing a tone generating process in response to the performance event.
    Type: Grant
    Filed: January 15, 1999
    Date of Patent: August 24, 1999
    Assignee: Yamaha Corporation
    Inventor: Takao Yamamoto
  • Patent number: 5911170
    Abstract: A method is disclosed for synthesizing acoustic waveforms, especially musical instrument sounds. The acoustic waveforms are characterized by time-varying amplitudes, frequencies and phases of sinusoidal components. These time-varying parameters, at each analysis frame, are obtained in one embodiment by short term Fourier transforms (STFT). The spectrum envelope at each frame is parameterized with an autoregressive moving average model and applied to a waveform consisting of unit amplitude sinusoids via time-domain filtering. The resulting synthetic waveform preserves the time-varying frequency and phase information and has the same relative energy distribution among different sinusoidal components as that of the original signal. Finally, a general waveform shape for the type of acoustic signal being synthesized is applied.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: June 8, 1999
    Assignee: Texas Instruments Incorporated
    Inventor: Yinong Ding
  • Patent number: 5900570
    Abstract: This invention provides a circuit for synthesizing musical sounds. In one embodiment, the circuit includes a first order FIR highpass filter that is placed between a modulation phase increment oscillator and a carrier phase increment oscillator. The invention may also include waveshaping circuits, adders, multipliers, time division multiplexing, and other types of filters. Another embodiment of the invention provides a music synthesis method where a modulation phase increment is multiplied by a modulation index to produce a modulation signal. That modulation signal is then filtered and added to a carrier phase increment. Finally, that sum is multiplied by an amplitude envelope to produce a signal representing a musical sound. The method may include using a first order FIR highpass filter, waveshaping of both sinusoidal and non-sinusoidal waveforms, additional multiplying and time division multiplexing. The invention also includes self-modulation and cascading.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: May 4, 1999
    Assignee: Creative Technology, Ltd.
    Inventor: David P. Rossum
  • Patent number: 5886276
    Abstract: An audio signal analyzer and encoder is based on a model that considers audio signals to be composed of deterministic or sinusoidal components, transient components representing the onset of notes or other events in an audio signal, and stochastic components. Deterministic components are represented as a series of overlapping sinusoidal waveforms. To generate the deterministic components, the input signal is divided into a set of frequency bands by a multi-complementary filter bank. The frequency band signals are oversampled so as to suppress cross-band aliasing energy in each band. Each frequency band is analyzed and encoded as a set of spectral components using a windowing time frame whose length is inversely proportional to the frequency range in that band. Low frequency bands are encoded using longer time frames than higher frequency bands.
    Type: Grant
    Filed: January 16, 1998
    Date of Patent: March 23, 1999
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Scott N. Levine, Tony S. Verma
  • Patent number: 5814750
    Abstract: A method for resampling includes convolving a given set of samples with the impulse response function of a low-pass filter. In this method, values of the impulse response required for the convolution calculation are computed at the time of resampling from a segmented polynomial approximating the impulse response. In one embodiment, the method is applied to provide musical tones of various pitches from a stored waveform.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: September 29, 1998
    Assignee: Chromatic Research, Inc.
    Inventors: Avery L. Wang, Brooks S. Read
  • Patent number: 5787023
    Abstract: A digital filter device, for an electronic musical instrument, comprises: filter coefficient generation means for generating a set of filter coefficients in consonance with a designated resonance frequency and Q; and filter operation means for performing an operation for an IIR digital filter, relative to an input tone wave, by using the filter coefficient, which is generated by the filter coefficient generation means, with the filter coefficient generation means including trigonometric function output means, for outputting a trigonometric function value that is consonant with the resonance frequency, and filter coefficient calculation means, for calculating a plurality of filter coefficients based on the Q and the trigonometric function value that is generated by the trigonometric function output means, and with the filter coefficient calculation means having segment approximation means for performing, within a range of x.gtoreq.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: July 28, 1998
    Assignee: Kabushiki Kaisha Kawai Gakki Seisakusho
    Inventor: Taichi Kosugi
  • Patent number: 5777255
    Abstract: An efficient digital waveguide synthesizer is disclosed for simulating the tones produced by a non-linearly excited vibrational element coupled to a resonator, such as in a piano. In a preferred embodiment, the synthesizer creates an excitation pulse from a table containing the impulse response of a piano soundboard and enclosure. Alternatively, this excitation pulse can be synthesized by filtering white noise. The excitation pulse is fed into a filter that simulates the collision of the piano hammer and string. Because the hammer-string interaction is nonlinear, the characteristics of this filter vary with the amplitude of the tone produced. The filtered excitation pulse is then fed into a filtered delay line loop which models the vibration of a piano string. Because the excitation pulse already contains the effects of the resonator, the tone produced by the delay line loop does not require additional filtering in order to model the resonator.
    Type: Grant
    Filed: May 2, 1997
    Date of Patent: July 7, 1998
    Assignee: Stanford University
    Inventors: Julius O. Smith, III, Scott A. Van Duyne
  • Patent number: 5748513
    Abstract: A coupled mode digital filter which simulates any number of arbitrarily tuned modes coupled together so as to share the same loss element at a junction loaded by an arbitrary impedance function is formed from the combination of one first order allpass filter ?28! and one unit delay ?30! per mode and one shared coupling filter?36!.
    Type: Grant
    Filed: August 16, 1996
    Date of Patent: May 5, 1998
    Assignee: Stanford University
    Inventor: Scott A. Van Duyne
  • Patent number: 5744743
    Abstract: The present invention relates to a pedal resonance effect simulation device for digital pianos consisting of a resonance effect circuit for the simulation of the resonance effects in the strings of a traditional mechanical piano, coupled with a reference model which varies the resonance contributions of the various strings, which are equivalent to those of a mechanical piano, by using delay lines with a method which considers the position of the resonance pedal pressed by the performer upon reproduction.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: April 28, 1998
    Assignee: Generalmusic S.P.A.
    Inventors: Giovanni De Poli, Francesco Campetella, Giampaolo Borin
  • Patent number: 5744742
    Abstract: A parametric signal modeling musical tone synthesizer utilizes a multidimensional filter coefficient space consisting of many sets of filter coefficients to model an instrument. These sets are smoothly interpolated over pitch, intensity, and time. The filter excitation for a particular note is derived from a collection of single period excitations, which form a multidimensional excitation space, which is also smoothly interpolated over pitch, intensity and time. The synthesizer includes effective modeling of attacks of tones, and the noise component of a tone is modelled separately from the pitched component. The input control signals may include initial pitch and intensity, or the intensity may be time-varying. A variety of instruments may be specified.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: April 28, 1998
    Assignee: EuPhonics, Incorporated
    Inventors: Eric Lindemann, Jeffrey Barish
  • Patent number: 5744739
    Abstract: A variable sample rate approximation technique is used for coding and recreating musical signals in a wavetable synthesizer. Many sounds inherently include one large fast transfer of energy followed by vibrations that dampen over time so that the bandwidth requirement of a musical sound is reduced with passing time. Using the variable sample rate approximation technique, musical sounds are classified into two categories, sustaining sounds and percussive sounds. A sustaining instrument creates a noisy stimulus then sustains the sound created by the noisy stimulus. A percussive instrument is also a noisy source and generates a sound signal having high frequencies that decay rapidly while sustaining instruments sustain at all frequencies nearly equally. The sustaining and percussive instruments have substantially different waveform characteristics but present similar conditions with respect to memory reduction.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: April 28, 1998
    Assignee: Crystal Semiconductor
    Inventor: Michael V. Jenkins
  • Patent number: 5740716
    Abstract: A sound synthesis system employs a variable-length delay line whose length is modulated at a frequency that is close to the fundamental frequency of the delay line. By modulating the length of the delay line at a frequency close to the fundamental frequency of the delay line, a new class of sounds is generated. A delay line length modulator produces a periodic modulation signal whose frequency is close to the fundamental frequency of the delay line. The length of the delay line is modulated in accordance with the modulation signal, thereby causing a variable pitch shifting effect in the waveform produced by the delay line structure. Since the length of the delay line is modulated at a frequency close to the average loop frequency, part of the waveform stored by the delay line is time-compressed and the other part is expanded. The waveform's shape changes smoothly so that the compressed part of the waveform is pitched-shifted upwards, and the expanded part is pitch-lowered.
    Type: Grant
    Filed: May 1, 1997
    Date of Patent: April 21, 1998
    Assignee: The Board of Trustees of the Leland Stanford Juior University
    Inventor: Timothy S. Stilson
  • Patent number: 5731533
    Abstract: A musical tone signal forming apparatus includes a pickup which detects vibrations of a string of an electric guitar and produces a string vibration signal. The string vibration signal and the output of a first delay imparting a first delay time are combined in a first combiner. Second and third delays impart second and third delay times to the string vibration signal, respectively. Delayed signals from the second and third delays are combined in a second combiner. Outputs of the first and second combiners are combined in a third combiner. The first delay time is determined by the distance between a bridge and a first imaginary pickup supposed to detect vibrations of the string. The second delay time is determined by the distance between the first imaginary pickup and a second imaginary pickup supposed to be disposed nearer to the bridge. The third delay time is determined by the distance between the bridge and the mid-point of the first and second imaginary pickups.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: March 24, 1998
    Assignee: Roland Corporation
    Inventor: Atsushi Hoshiai
  • Patent number: 5712439
    Abstract: A musical tone signal producing apparatus having a loop circuit portion including a filter circuit and a delay circuit for circulating therethrough a vibratory waveform signal to be produced as a musical tone signal and a control signal generator for generating a first control signal for effecting excitation of the waveform signal in the loop circuit and applying the first control signal to the filter circuit and for generating a second control signal for applying time variation to the waveform signal. The musical tone signal producing apparatus further includes a filter control circuit for modifying the second control signal based on the vibratory waveform signal and for applying a control parameter defined by the modified second control signal to the filter circuit for control of a signal transmission characteristic of the filter circuit.
    Type: Grant
    Filed: September 12, 1995
    Date of Patent: January 27, 1998
    Assignee: Yamaha Corporation
    Inventor: Kunimoto Toshifumi
  • Patent number: 5698807
    Abstract: An electronic music system which imitates acoustic instruments addresses the problem wherein the audio spectrum of a a recorded note is entirely shifted in pitch by transposition. The consequence of this is that unnatural formant shifts occur, resulting in the phenomenon known in the industry as "munchkinization." The present invention eliminates munchkinization, thus allowing a substantially wider transposition range for a single recording. Also, the present invention allows even shorter recordings to be used for still further memory improvements. An analysis stage separates and stores the formant and excitation components of sounds from an instrument. On playback, either the formant component or the excitation component may be manipulated.
    Type: Grant
    Filed: March 5, 1996
    Date of Patent: December 16, 1997
    Assignee: Creative Technology Ltd.
    Inventors: Dana C. Massie, David P. Rossum
  • Patent number: 5691496
    Abstract: Only in a transient band of a filter, substantially all frequency bands of the musical tone waveform are subjected to filter processing. Due to this, the drawback that the amount of change of the frequency characteristic of the musical tone gradually changes as a whole from a fundamental wave toward a harmonics and only one part of the frequency characteristic of the musical tone changes is eliminated.Also, the density of frequency components of the frequency band of the musical tone waveform does not change, the related frequency band is shifted in frequency, subjected to filter processing, and further shifted to a frequency in accordance with the musical tone pitch. Due to this, a specific range of the filter characteristic is selected, and the musical tone is subjected to the filter control only within this range.
    Type: Grant
    Filed: February 14, 1996
    Date of Patent: November 25, 1997
    Assignee: Kawai Musical Inst. Mfg. Co., Ltd.
    Inventors: Takashi Suzuki, Seiji Okamoto, Katsushi Ishii, Yutaka Washiyama
  • Patent number: 5687105
    Abstract: A digital signal processor (i.e., DSP) is employed by an electronic musical instrument. The contents of operational processes to be executed by the DSP can be arbitrarily set in accordance with filtering operations of the filters to be realized. A processing device to be embodied by the DSP at least contains a microprogram memory, a coefficient register, a delay memory and a processing portion. A desired set of coefficients are read from the coefficient register in accordance with a first address signal, while a desired program is read from the microprogram memory in accordance with a second address signal. Each program contains at least one operational command or one instruction. The value of each of the first and second address signals is periodically changed in each sampling period.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: November 11, 1997
    Assignee: Yamaha Corporation
    Inventors: Hideo Miyamori, Masatada Wachi, Mitsumi Kato
  • Patent number: 5641931
    Abstract: In a device which excites an oscillating signal in a closed loop containing a delay circuit and a filter so as to synthesize a sound of pitch corresponding to the total delay time in the closed loop, arithmetic operations are performed in the closed loop, in response to a change in a color controlling coefficient caused during generation of the sound, for interpolating delayed output signals from plural points in the loop having different delay time. This interpolation compensates for a variation in the signal delay time in the closed loop resultant from the change in the filter coefficient, to allow the entire closed loop to provide such a total delay time that excites oscillation corresponding to a desired pitch. The closed loop also includes first and second filters.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: June 24, 1997
    Assignee: Yamaha Corporation
    Inventors: Yoichiro Ogai, Iwao Higashi
  • Patent number: 5631434
    Abstract: A filtering apparatus for an electronic musical instrument includes at least a digital filter. The digital filter has a frequency characteristic determined by a filtering parameter and performs a filtering operation on a musical tone signal inputted thereto. In addition, the filtering parameter is changed in accordance with a keycode signal representing a tone pitch of the musical tone signal. Thus, the frequency characteristic is varied in accordance with a keycode signal.
    Type: Grant
    Filed: April 11, 1995
    Date of Patent: May 20, 1997
    Assignee: Yamaha Corporation
    Inventor: Toda Hiroyuki
  • Patent number: 5621801
    Abstract: A reverberation effect imparting system includes plural comb filters, each of which has a signal delay line and a feedback loop for filtering a delayed output signal from the delay line and feeding the filtered signal back to the input side with a variable loop gain. The device further includes a junction section which receives the respective output signals from the delay lines of the plural comb filters. The junction section controls the received signals with respective variable scattering coefficients and sums up the thus-controlled signals, so as to introduce the summed signal into the feedback loop of each of the comb filters. In this manner, reverberation control according to the waveguide theory is performed by the junction section, while the conventional-type reverberation control is performed by the comb filters. Thus, reverberation can be controlled through a combination of the two controls.
    Type: Grant
    Filed: June 9, 1994
    Date of Patent: April 15, 1997
    Assignee: Yamaha Corporation
    Inventors: Toshifumi Kunimoto, Masahiro Kakishita, Chifumi Takeuchi
  • Patent number: 5597970
    Abstract: In the waveform processing apparatus of the present invention, an original sound signal is divided into a plurality of bands, parameters such as amplitude and frequency are extracted for each band, and correction is made so that the amount of deviation of the parameters from the mean value thereof is gradually decreased to zero from a certain time to the time when the repetition period begins, whereby a musical tone signal is re-synthesized based on the corrected parameters. The electronic musical instrument which stores the waveforms processed by the apparatus of the present invention generates musical tones having more natural tone color change.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: January 28, 1997
    Assignee: Kabushiki Kaisha Kawai Gakki Seisakusho
    Inventors: Hiroshi Sato, Kaoru Matsunaga
  • Patent number: 5587548
    Abstract: A tone synthesis system employs a filtered delay loop which is excited by an excitation signal. The excitation signal corresponds to a partial impulse response of a body filter to the system which is to be simulated. Additional components of the impulse response of the body filter are imparted to an output from the filtered delay loop. High quality tone synthesis can be achieved without the necessity of providing a complicated body filter.
    Type: Grant
    Filed: September 1, 1994
    Date of Patent: December 24, 1996
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventor: Julius O. Smith, III
  • Patent number: 5583309
    Abstract: A musical tone generating apparatus is provided for a keyboard electronic musical instrument. The apparatus consists of a musical tone source, a coefficient generator, a digital filter and so on. The coefficient generator generates at least one time dependence coefficient, and applies It to output of the digital filter. The parameter controller changes at least one parameter, which designates tone color of the musical tone, in accordance with the time dependent coefficient to thereby realize time-variant changing rate of envelope of musical tone. And, the coefficient generator and the parameter controller are used by means of time sharing technique. That is, the coefficient is used as plural units, wherein each unit generates a coefficient in each stage, and the digital filter is also used as plural units. Each digital filter unit changes a parameter of tone color of the musical tone in accordance with the coefficient supplied thereto.
    Type: Grant
    Filed: October 5, 1993
    Date of Patent: December 10, 1996
    Assignee: Yamaha Corporation
    Inventor: Yoshio Fujita
  • Patent number: 5578781
    Abstract: There are provided an analyzer which processes a supplied original sound waveform signal so as to generate one or more analyzed waveform signal components, a synthesizer which receives and processes at least one of the analyzed waveform signal components from the analyzer so as to synthesize a waveform signal on the basis of the processing, and a control section which controls the respective parameters used in the analyzer and synthesizer independently of each other. At least output signal of the synthesizer is taken out and output as a tone signal. In order to achieve diversified control of the tone color or characteristic of a tone to be generated, a tone signal may be obtained by taking out the respective output signals of the analyzer and synthesizer for synthesis.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: November 26, 1996
    Assignee: Yamaha Corporation
    Inventor: Hideo Suzuki
  • Patent number: 5536903
    Abstract: A musical tone synthesizing apparatus at least comprises two loop circuits. Each loop circuit delays an input signal thereof by a delay time corresponding to a tone-pitch period of a musical tone to be produced while circulating the input signal therethrough. When the loop circuits are connected in series, an excitation signal is applied to one loop circuit, while an output signal of one loop circuit is supplied to another loop circuit. Then, the excitation signal is mixed together with the output signals of the loop circuits, so that a musical tone signal representing a synthesized musical tone is generated. The excitation signal is generated by mixing a noise signal and a musical-tone-waveform signal. When simulating the violin sounds, the noise signal is made based on a frictional sound which is caused due to a friction between a string and a bow. Incidentally, a filter can be provided to perform a filtering operation on each of the excitation signal and the output signals of the loop circuits.
    Type: Grant
    Filed: March 14, 1994
    Date of Patent: July 16, 1996
    Assignee: Yamaha Corporation
    Inventors: Toru Kitayama, Akira Yamauchi
  • Patent number: 5521329
    Abstract: A musical tone synthesizing apparatus provides a closed loop containing an adder, a delay circuit, a filter and a gain control portion. The delay circuit has a delay time which is set responsive to a tone pitch of a musical tone to be produced. An excitation signal is produced in response to the musical tone to be produced and is introduced into the closed loop through the adder, so that the excitation signal circulates through the closed loop. The gain control portion is provided to control a loop gain of the closed loop on the basis of a preset parameter and another parameter which is controlled responsive to a tone color of the musical tone to be produced. The signal circulating through the closed loop is picked up as a musical tone signal representing the musical tone to be produced. By controlling the loop gain of the closed loop, an attenuation characteristic of the musical tone signal is controlled. Hence, it is possible to freely control a sounding time of a decay sound such as a guitar sound.
    Type: Grant
    Filed: January 21, 1994
    Date of Patent: May 28, 1996
    Assignee: Yamaha Corporation
    Inventors: Akira Yamauchi, Masashi Hirano
  • Patent number: 5521328
    Abstract: An electronic musical instrument simulating a wind instrument is fundamentally configured by a loop circuit at least containing a linear portion and a non-linear portion. The linear portion simulates a pipe portion of the wind instrument, while the non-linear portion simulates a breath-blowing portion of the wind instrument so as to produce an excitation signal, which is supplied to the linear portion. By an interaction between the linear portion and the non-linear portion which is carried out while a signal circulates through the loop circuit, a sounding characteristic of the wind instrument is simulated. In order to accurately simulate a jet reed instrument (e.g., organ pipe), there are further provided a delay circuit and an edge tone generator. The delay circuit imparts a delay time to the output signal of the linear portion, and then, a delayed signal is supplied to the non-linear portion.
    Type: Grant
    Filed: August 18, 1993
    Date of Patent: May 28, 1996
    Assignee: Yamaha Corporation
    Inventor: Masahiro Kakishita
  • Patent number: 5519167
    Abstract: In a musical tone synthesizing apparatus, employed by an electronic musical instrument, an excitation signal circulates through a waveguide to form a musical tone signal corresponding to a synthesized musical tone. The waveguide is configured by a loop circuit containing an adder, a delay circuit, a filter and an amplifier. A delay time used for the delay circuit is determined in response to a tone pitch of a musical tone to be produced, while a filter coefficient used for the filter is determined in response to a tone color of the musical tone to be produced. A multiplication coefficient used for the multiplier is generated in accordance with one of the tone pitch and delay time; or the multiplication coefficient is computed on the basis of the tone pitch and a decay rate which is set by a performer. In addition, a different multiplication coefficient can be generated in response to a state of an envelope waveform of the musical tone to be produced.
    Type: Grant
    Filed: August 4, 1994
    Date of Patent: May 21, 1996
    Assignee: Yamaha Corporation
    Inventors: Toshifumi Kunimoto, Hideyuki Masuda, Toru Kitayama
  • Patent number: 5508473
    Abstract: A music synthesizer simulates the musical tones of wind instruments. The synthesizer includes a vopex noise generator, an edge tone nonlinearity function driven by the differential between a blowing pressure signal and a feedback signal from the resonator. The vopex noise generator feeds its noise output signal back into itself so as to generate a noise "votex". The vopex noise generator furthermore modulates the spectral content of the generated noise fluctuates in a manner that is period synchronous with the resonator output signal. As a result, the noise vopex signals mimic the turbulence associated with air blown into wind instruments by switching between structured and chaotic modes of operation in a manner that is period synchronous with the resonator output signal. The transfer characteristic of the edge tone nonlinearity function is dynamically controlled by the noise signal so as to change the operating point of the edge tone nonlinearity.
    Type: Grant
    Filed: May 10, 1994
    Date of Patent: April 16, 1996
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventor: Christopher D. Chafe
  • Patent number: 5502277
    Abstract: A filter device has a variable frequency cut-off characteristic as well as a variable gain characteristic. To obtain these characteristics, a filtering operation is performed on data input thereto on the basis of a transmission function, which is defined by gain G for predetermined frequencies and a frequency fo corresponding to a phase at an intersection of a unit circle and a straight line intersecting at right angles a real axis passing a midpoint between a polar and a zero point on the real axis on Z-plane. An electronic musical instrument employing the filter device can change amplitudes of frequency components involved in musical tones on the basis of performance data, generating musical tones involving complex harmonics and having various tone colors, as a conventional acoustic instrument does.
    Type: Grant
    Filed: May 2, 1995
    Date of Patent: March 26, 1996
    Assignee: Casio Computer Co., Ltd.
    Inventor: Goro Sakata
  • Patent number: 5498835
    Abstract: A designating mechanism generates filtering designation data, which designate the contents of filtering, reverberating designation data, which designate the contents of reverberation, and characteristics data, which express the combined contents of filtering and reverberation. A parameters generating mechanism generates filtering parameters expressing filtering characteristics, and generates reverberating parameters expressing reverberation characteristics. A readout device reads out a first operating algorithm, which designates filtering designation data, and a second operating algorithm, which designates reverberating designation data, from a memory mechanism wherein a plurality of operating algorithms are stored.
    Type: Grant
    Filed: March 10, 1993
    Date of Patent: March 12, 1996
    Assignee: Yamaha Corporation
    Inventor: Tetsuji Ichiki
  • Patent number: 5496964
    Abstract: A tone generator for an electronic musical instrument is fundamentally configured by a drive-waveform creating portion and a closed loop. The drive-waveform creating portion creates a drive-waveform signal by mixing an excitation waveform and a noise waveform together. The drive-waveform signal is applied to the closed loop through an adder. The closed loop contains a plurality of feedback paths, each of which at least contains a delay circuit and an all-pass filter. The adder adds all of output signals of the feedback paths together with the drive-waveform signal so as to produce a musical tone signal. The number of delay stages, representing an amount of delay to be used in each delay circuit provided in each feedback path, is designated in response to a delay ratio which is arbitrarily set.
    Type: Grant
    Filed: March 24, 1994
    Date of Patent: March 5, 1996
    Assignee: Yamaha Corporation
    Inventor: Hideo Suzuki
  • Patent number: 5466884
    Abstract: A musical sound synthesizer simulates interaction of a hammer having a compressible striking surface with a resonating medium. A digital waveguide resonator that simulates operation of a resonating medium and generates digital resonator waveforms representing signals propagating in said digital waveguide resonator. A hammer filter simulates the hammer striking the resonating medium and generates first and second hammer waveforms. The hammer filter includes a scattering junction that couples the hammer filter to the digital waveguide resonator.
    Type: Grant
    Filed: May 10, 1994
    Date of Patent: November 14, 1995
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Scott A. Van Duyne, Julius O. Smith, III
  • Patent number: 5459280
    Abstract: A musical tone synthesizing apparatus for generating a musical tone which is influenced not only by blowing pressure and embouchure, etc. but also effected by the movement of a performer's tongue. The apparatus comprises an operating part WC having a mouthpiece part and a reed part; a breath measuring sensor for measuring breath passing through the mouthpiece part; a tonguing detector for measuring the relative position of a performer's tongue to the reed part; a musical tone forming circuit TC for simulating the mouthpiece, the reed, and the resonance tube of the acoustic wind instrument in response to an output signal of the breath measuring sensor so as to create a musical tone signal; and a tonguing effector for changing a simulating characteristic of the reed of the acoustic wind instrument in response to an output signal of the tonguing detector.
    Type: Grant
    Filed: May 27, 1993
    Date of Patent: October 17, 1995
    Assignee: Yamaha Corportion
    Inventors: Hideyuki Masuda, Toshifumi Kunimoto
  • Patent number: 5448010
    Abstract: A tone generation system includes one or more digital waveguide networks coupled to one or more junctions, one of which receives a control signal for controlling tone generation. The control signal initiates and interacts with a wave signal propagating through the waveguide networks to form a tone signal. A non-linear junction may be employed which receives a signal from a waveguide, converts it in accordance with a non-linear function based upon the value of the control signal and provides it back to the waveguide. A tone signal whose pitch is determined by the wave transmission characteristics of the waveguide network is thereby produced.
    Type: Grant
    Filed: March 22, 1993
    Date of Patent: September 5, 1995
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventor: Julius O. Smith, III
  • Patent number: 5442130
    Abstract: The musical tone synthesizing apparatus utilizes a loop circuit receptive of an input signal for looping the same with a given delay time to produce an output signal representative of a musical tone. The loop circuit includes a delay element for delaying the input signal and a feedback path for feeding back the delayed input signal to the delay element. A control unit is provided for controlling the delay element according to a designated pitch of a musical tone so as to set the delay time of the loop circuit to thereby determine the pitch of the musical tone. A generator generates the input signal containing various frequency components. A high-pass filter is connected precedingly to the loop circuit for selectively attenuating relatively lower frequency components of the input signal, which have periods longer than the set delay time of the loop circuit.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: August 15, 1995
    Assignee: Yamaha Corporation
    Inventors: Toru Kitayama, Yoichiro Ogai
  • Patent number: 5438156
    Abstract: An acoustic wind instrument having a conical tube is simulated by two cylindrical tubes communicated to each other at each one end. A parallel connection of electrical signal transmission lines, each simulating a cylindrical tube constitute a synthesizer synthesizing the sound of the conical acoustic wind instrument. Each signal transmission line includes a shift register for giving a delay to the input signal, a multiplier for simulating sound reflection, and a filter for affording a tone color. An exciting signal is injected at the interconnection of the parallel connection through a junction circuit.
    Type: Grant
    Filed: May 5, 1992
    Date of Patent: August 1, 1995
    Assignee: Yamaha Corporation
    Inventors: Hideyuki Masuda, Toshifumi Kunimoto
  • Patent number: 5432296
    Abstract: The musical tone synthesizing apparatus is mainly configured by a closed loop which at least provides a delay circuit and an all-pass filter. The delay circuit delays an input signal (e.g., excitation wave signal) by a first delay time corresponding to a certain integral number of sampling periods. The all-pass filter functions to at least delay an output of the delay circuit by a second delay time corresponding to a decimal fraction of the sampling period, so that an output of the all-pass filter is fed back to the delay circuit. The whole delay time of the closed loop consists of the first and second delay times which can be respectively controlled. Thus, a musical tone signal representing a synthesized musical tone (e.g., an attenuating sound which is produced from an percussion instrument) is picked up from the closed loop. Incidentally, the whole configuration of the closed loop can be embodied by a digital signal processor (DSP).
    Type: Grant
    Filed: August 18, 1993
    Date of Patent: July 11, 1995
    Assignee: Yamaha Corporation
    Inventors: Chifumi Takeuchi, Iwao Higashi
  • Patent number: 5428185
    Abstract: A musical tone synthesizing apparatus synthesizes musical tones by simulating the tone generation construction of an acoustic musical instrument. The acoustic musical instrument comprises of a tone generating element and a tone generating operator for exciting the tone generating element, thereby creating reciprocally propagating vibration within the tone generating element. The musical tone synthesizing apparatus has a parameter producing portion which automatically produces a plurality of control parameters used for controlling a simulation of the acoustic musical instrument in response to operational information representing the operation applied to the acoustic musical instrument by a performer, musical tone synthesizing portion which synthesizes a musical tone of the acoustic musical instrument, wherein the operation of the musical tone synthesizing portion is controlled in accordance with the control parameters. The parameter producing portion includes, for example, keyboard apparatus having a keyboard.
    Type: Grant
    Filed: August 24, 1993
    Date of Patent: June 27, 1995
    Assignee: Yamaha Corporation
    Inventors: Toshifumi Kunimoto, Mitsuru Fukui
  • Patent number: 5428183
    Abstract: A tone signal generating apparatus, including a memory for storing wave data containing frequency components within a full band; a tone generator for reading the wave data from the memory in accordance with key ON/OFF data to generate a tone signal; a velocity generator for generating a velocity value based on key ON/OFF data; a first coefficient processor for producing a first coefficient to control the amplitude in accordance with the velocity value generated by the velocity generator; a first operator for performing an operation on the first coefficient produced by the first coefficient processor and the tone signal generated by the tone generator, a filter for extracting frequency components within a specific band from the tone signal output from the first operator to produce a first tone signal and outputting the first tone signal; a second coefficient processor for producing a second coefficient to control the amplitude in accordance with the velocity value generated by the velocity generator; and a sec
    Type: Grant
    Filed: December 17, 1993
    Date of Patent: June 27, 1995
    Assignee: Kabushiki Kaisha Kawai Gakki Seisakusho
    Inventors: Eiji Matsuda, Hiroshi Kitagawa, Gen Izumisawa, Jiro Tanaka
  • Patent number: 5426262
    Abstract: An electronic musical instrument: is provided to perform an active control on the pitch of the musical tone to be generated, thereby simulating the pitch-rising phenomenon to be occurred in the performance of a non-electronic musical instrument such as a wind instrument, percussion instrument and stringed instrument. In case of the simulation of the wind instrument, this electronic musical instrument is mainly configured by an excitation-vibration circuit and a tube simulation circuit which are connected together by means of a junction. The tube simulation circuit is configured by a closed-loop circuit in which plural delay circuits and junction circuits are connected together in cascade-connection manner. Herein, the delay circuits simulate the propagation delay of the air-pressure wave to be transmitted through the tube of the wind instrument, while the junction circuits simulate the scattering manner of the air-pressure wave at the points at which the diameter of the tube is changed.
    Type: Grant
    Filed: July 23, 1992
    Date of Patent: June 20, 1995
    Assignee: Yamaha Corporation
    Inventors: Toru Kitayama, Iwao Higashi, Tomoyuki Funaki
  • Patent number: 5408042
    Abstract: When playing a wind instrument such as a clarinet, noises are inevitably or intentionally generated under effect of a turbulent flow contained in an air-pressure wave propagated through a resonance tube of the wind instrument. In response to an accurate simulation of a noise behavior, particularly, a behavior of the turbulent flow contained in the air-pressure wave, a musical tone synthesizing apparatus artificially produces a noise signal by use of a white-noise signal having the predetermined uniform spectral distribution. Herein, frequency characteristic and amplitude characteristic of this noise signal are controlled to be varied in response to an excitation signal which is created responsive to performance information representing the breath pressure applied to a mouthpiece of the wind instrument. This excitation signal is delayed by the predetermined delay time while it is circulating through a loop circuit.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: April 18, 1995
    Assignee: Yamaha Corporation
    Inventor: Hideyuki Masuda
  • Patent number: 5403969
    Abstract: In a tone signal synthesizer for synthesizing a tone signal by supplying a driving signal, into a closed loop circuit including a delay circuit and a filter, a filter coefficient which controls the characteristic of the filter is changed while a musical tone is generated. For example, a set of filter coefficients are provided at the time of key-on and are switched to another set of filter coefficients when a predetermined time is passed after the time of key-on. The set of filter coefficients are switched to a further set of filter coefficients at the time of key-off and then are switched to a still further set of filter coefficients when a predetermined time is passed after the time of key-off. It is possible to generate a musical tone which changes more complexly on the basis of the change of the filter characteristic, with the passage of time.
    Type: Grant
    Filed: July 7, 1994
    Date of Patent: April 4, 1995
    Assignee: Yamaha Corporation
    Inventor: Takaaki Muto
  • Patent number: 5389730
    Abstract: An emphasize system for an electronic musical instrument including filter and control device. The filter extract and output predetermined frequency range component of an input musical tone signal. The control device control the level of an output from the filter at least on the basis of an output from an envelope generator which controls the level of the input musical tone signal, or on the basis of the level of another frequency range component of the input musical tone signal. At least the level controlled signal is outputted from the system.
    Type: Grant
    Filed: March 20, 1991
    Date of Patent: February 14, 1995
    Assignee: Yamaha Corporation
    Inventor: Masatada Wachi
  • Patent number: 5386082
    Abstract: A method of detecting localization of an acoustic image, in which an acoustic impulse is emitted from a sound source to a dummy of a human head, an acoustic sensor is provided to a portion of the dummy's ears, and the response waveform is received by the acoustic sensor. This enables the detection of what effects are derived from interruption, reflection, and the like of a tone due to the human head. The received response waveform is analyzed and parameters for an acoustic image localization system are obtained. The acoustic image localization system comprising a delay circuit, a filter and an amplification controller sets the parameters into the delay circuit, the filter and the amplification controller, so that the detected localization of an acoustic image is reproduced.
    Type: Grant
    Filed: October 30, 1992
    Date of Patent: January 31, 1995
    Assignee: Yamaha Corporation
    Inventor: Iwao Higashi