Gesture synthesizer for electronic sound device

Abstract

A MIDI-compatible gesture synthesizer is provided for use with a conventional music synthesizer to create musically realistic<DEL-S DATE="20020416" ID="DEL-S-00001" / >ally<DEL-E ID="DEL-S-00001" / > sounding gestures. The gesture synthesizer is responsive to one or more user controllable input signals, and includes several transfer function models that may be user-selected. One transfer function models properties of muscles using Hill's force-velocity equation to describe the non-linearity of muscle activation. A second transfer function models the cyclic oscillation produced by opposing effects of two force sources representing the cyclic oppositional action of muscle systems. A third transfer function emulates the response of muscles to internal electrical impulses. A fourth transfer function provides a model representing and altering virtual trajectory of gestures. A fifth transfer function models visco-elastic properties of muscle response to simulated loads. The gesture synthesizer outputs <DEL-S DATE="20020416" ID="DEL-S-00002" / >MIDI-compatible<DEL-E ID="DEL-S-00002" / > continuous pitch data, tone volume and tone timbre information. The continuous pitch data is combined with discrete pitch data provided by the discrete pitch generator within the conventional synthesizer, and the combined signal is input to a tone generator, along with the tone volume and tone timbre information. The tone generator outputs tones that are user-controllable in real time during performance of a musical gesture.

Description

FIELD OF THE INVENTIONBACKGROUND OF THE INVENTIONMusical instruments are manipulated by a musician-user to articulate and produce notes of discrete tones having constant pitch. For example, a guitar has strings and a finger board with frets that divide the guitar strings into discrete lengths. By pressing a string against a fret with a finger, a musician can select equally spaced pitches. Each musical note need not be articulated separately. Some notes may be played merely by changing the pitch of a previously articulated note, and pitch may frequently be altered to glide continuously between notes.To more fully appreciate the present invention, it is helpful to define several terms commonly used by professional musicians. "Pitch" is the subjective sensation produced by a periodic vibration having constant frequency, e.g., what may be produced by a picked (or plucked) guitar string that is under tension. The sensation of pitch is logarithmically related to the frequency of vibration...

AI Technical Summary

Benefits of technology

The present invention provides a musical synthesizer with a gesture synthesizer that modifies musical gestures. Applicant has recognized that conventional tone synthesizers reproduce the sensation of tone created by an acoustic instrument by modeling human aural perception processes, and representing these processes parametrically. In contrast to the prior art however, the present invention recognizes that a missing musical parameter or parameters may be defined, representing a perceptual quality or qualities, related to the trajectory of a gesture and to the continuous variation of its trajectory. Gestures are controlled using feedback loops between the eyes and ears of a performer and their muscles. Additionally receptors in muscles transmit information about position, speed, and acceleration of gestures back to the higher brain centers involved in muscle activation and control. Such processes allow performers to formulate and continuously modify gesture trajectories in very precise ways.

A gesture synthesizer according to the present invention permits performance of several gestures simultaneously or sequentially in any order, and permits at least one gesture simulation parameter to be modified in real time during performance. Preferably a parametric menu-driven interface permits user-specification of gesture types by selection of synthesis functions and non-real time modification of programming arguments.

Problems solved by technology

Unfortunately, such mechanisms do not generally produce lifelike pitch inflections.

However, this produces a significantly different effect than a harp arpeggio because it requires discrete motions of the fingers used to strike each note.

But such prior art pitch altering mechanisms permit only a single type of gesture, and the sounds they produce do not include very expressive gestures.

In general, they do not permit combining gestures, or alteration of the gesture as it is performed.

In addition, no means of strumming chords is provided.

However, this does not produce a realistic sounding strum because it requires coordinating several discrete gestures by the player's fingers.

But even these more complex mechanisms produce sounds that are less expressive than desired because acoustic instruments (and the human voice) require some exertion to produce musically useful results.

But such mechanisms are expensive, bulky, and difficult to use, and require special circuitry to interface with electronic sound-production systems.

They also suffer from the same limitations as standard mechanical operators.

By implication, the prior art would regard as futile attempts to bend pitch in more than one direction.

Unfortunately, mono mode does not create effective slurs because on real musical instruments pitch changes that create slurs do not occur suddenly, but have a characteristic pitch change curve.

While such curves produce a recognizable effect peculiar to synthesizers, they do not realistically duplicate natural sounding portamentos performed on actual musical instruments.

Unfortunately the vibrato effect produced inevitably sounds automatic, and not lifelike.

Some prior art synthesizers include tables of pre-drawn transfer function curves, but do not provide a means of altering the predrawn-curves during performance.

Unfortunately, Usa's disclosed mechanical operator is sophisticated mechanically and thus expensive to manufacture.

Significantly, Usa fails to adequately specify means of simulating a variety of realistic gesture performance techniques.

Unfortunately, the output from Usa's device is not MIDI-compatible, and cannot be exported for use by other MIDI-compatible systems.

At best, however, what result is an unrealistic pitch bend sound that is quite unlike the pitch inflection actually produced by a musician using a traditional musical instrument.

Unfortunately the musical effects provided by prior art synthesizer 10 are not especially realistic.

Further, there is no means provided of modifying gesture trajectory in real time.

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