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CA2722916A1 - Musical instrument based on water-hammer, hydraulophonic, or hydraulidiophonic percussion - Google Patents

Musical instrument based on water-hammer, hydraulophonic, or hydraulidiophonic percussion


Publication number
CA2722916A1 CA 2722916 CA2722916A CA2722916A1 CA 2722916 A1 CA2722916 A1 CA 2722916A1 CA 2722916 CA2722916 CA 2722916 CA 2722916 A CA2722916 A CA 2722916A CA 2722916 A1 CA2722916 A1 CA 2722916A1
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CA 2722916
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French (fr)
Steve Mann
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Steve Mann
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    • G10D17/00Musical instruments not provided for in any of the preceding groups, e.g. Aeolian harp, singing-flame musical instrument
    • H04R1/00Details of transducers, loudspeakers or microphones
    • H04R1/44Special adaptations for subaqueous use, e.g. for hydrophone


A musical instrument or other multimedia input device is disclosed. User input is by way of hitting or striking water abruptly in order to produce an at least partially transient acoustic disturbance, vibrations, or change in the water. In one embodiment a dozen or so rigid pipes of various lengths (and possibly various diameters) emit fluid which is for being struck by a user at an open end of each pipe. The other end of each pipe is connected to an elastic tubing or other elastic medium, such as a diaphragm or bulb, resulting in a hydraulic resonator. In another embodiment the resonators are formed from variously sized Bordeaux wine bottles or Florence flasks encased completely in cement, except for the mouths of the bottles, each bottle having two additional holes drilled for a water inlet port and a listening port. Each hydraulic resonator is fitted with a sensor that senses the vibrations in the water and amplifies the vibrations into a sound reproduction system, such as an entirely acoustic impedance matcher or an electrical amplification system.


Industry Industrie AJAIJ Y/MID

1IIIlIU\ 201 0111 - C~PD ~P1C D001609430 BUREAU REGIONAL OE L'OPIC

of which the following is a specification...


io The present invention pertains generally to a new kind of hydraulic instrument, hy-draulic user-interface, or input/output device that may be used to control another multimedia system or events.


Existing musical instruments are divided into three categories: strings, percussion, and wind. Strings are essentially one dimensional solids (i.e. they are long and thin, having a relatively smal cross section). Percussion is typically a two-dimensional (i.e.
flat, and relatively thin) or three-dimensional (hulk) solid. Wind instruments run on matter in its gaseous state.
More generally, various researchers have categorized all known musical instrii-ments into five catogories: idiophones, rnembranopliones, chordophones.
aerophones, and electrophones. This categorization scheme was devised to categorize all possible musical instruments either known or to be made in the future. This system originated thousands of years ago, was adopted by Victor-Charles MMllahillon, and then further refined by Hornbostel and Sachs, and is often referred to as the Hornbostel Sachs Musical Instrument Classification Scheme.
The first three categories refer to solid matter, in three, two. and one dimension, i.e. idiophones make sound from bulk (3d) solid matter. Membranophones make sound from membranes (flat thin, essentially 2 dimensional solid matter).
Chordo-phones make sound from stings which are essentially one dimensional solid matter.
Another state-of-matter, namely liquid, has found relevance in musical instru-rnents. For example, the ancient Greeks and Romans used water as a supply of power, in order to blow air into organ pipes. These ancient instruments like the "wa-ter organ" or "hy draulis" used water as a power source. or as a means to store energy, which was then used to push wind through organ pipes.
In a similar way, modern church organs are examples of water organs because they use hydro-electricity (electricity that is generated by a waterfall) as a source of power to run the electric motor that powers the blower. which blows the wind (air) into the pipes to make the sound.
Sounds can also be produced underwater. For example, municipal swimming baths, various public and private pools, and the like, often have underwater loud-to speakers so that music can be played for people to hear underwater. This also fa-cilitates safety, so that ainiouncements over the Public Address (PA) system can be heard underwater.
Some animals such as dolphins and porpoises can make sounds underwater. They do this by having air pockets in which they make sound in air, which then is audible underwater.
Previously I invented a musical instrument that I call a hydraulophone in which sound is produced and/or controlled by vibrations in liquid matter. Typically the hydraulic fluid is water, and the instrument typically comprises 12 finger holes along the length of a pipe that resembles a giant Irish tin-whistle or recorder-flute. Water emerges from the 12 finger holes, and the instrument is played by inserting one or more fingers into one or more of the finger holes to stop or partially stop water from emerging. Blocking the water produces a gentle soothing organ-like sound or a flute-like sound. Each finger hole corresponds to it note on a natural musical scale, and chords may be played by blocking the water from coining out of more than one hole simultaneously. See, for example; See also my U.S. Patent 7,551,161, and associated priority documents, such as, for example, Canadian Patent 2499784. Dec 30, 2004.
Due to its gentle soothing sound and experientiality, the hydraulophone has found many uses in wellness centres, water therapy, rehabilitation, and the like, and its spirtually uplifting quality has been realized in its use as the organ for church services, concerts, playing hymns, and the like.
Its ability to smoothly vary a sound sculpture inakes it useful for motion picture sound tracks, and as a replacement for, or use with st rings ensembles and other fluidly flowing sound textures.
It has also been used in live theatrical productions to provide the acompanying music or sound track.
The hydraulophone is also being widely used in waterparks and children's play areas, where its slow and gently varying sound remains pleasantly soothing, even when children play notes at random. or play random chords and clusters.
More recently it is being adopted by rock and roll, and jazz musicians. A
common sentiment among jazz piano players is that it would be nice if the hydraulophone io responded more quickly, so that it could be used for jazz funk, reggae. and the like.
It has been said that it would be nice if the hydraulophone had the "quick attack"
capability of behaving like a guitar or piano, in addition to its ability to sustain notes like an organ or violin.


The following briefly describes my new invention. The new invention is a very fast-responding percussion-oriented hydraulophone or hydraulophone-like instrument.
Informally and metaphorically speaking, this new invention is to a guitar or piano, as the original hydraulophone invention is to a pipe organ or flute.
Now that I have said how the new invention compares to earlier hydraulophones, let inc also say how it relates to even older instruments, such as traditional instruments previously known throughout human history. Whereas previous musical instruments use solid or gas or informatics (e.g. electrophones) as the sound source, and user interface, the new invention makes possible new forms of sound production and/or user-interface possiblities using liquids, and in particular. played by striking liquids.
One drawback of the earlier hydraulophones is that the ruggedized versions in-stalled in children's playgrounds and waterparks tended to respond more slowly, owing to the need to mitigate the destructive effects of water hammer.
The new invention exploits the effects of water hammer in order to create a dra-matic and forceful transient response based on the immediate and powerful forces that liquids can create.
For example, one aspect of the invention allows an aquatic play device, fountain, pipe, hot tub, or the like to be equipped with a row of finger or hand holes from which water emerges to form a row of water openings that can be struck or slapped by a user.
Inside the device, there is, in some embodiments, the capacity to hold water in a rigid-walled straight tube connected to each hole, and then connected to each of those water-holding capacities, there is an elastic tubing.
In one embodiment I used 12 rigid plastic toilet/faucet tubes, cut, to various lengths to form a natural scale from a 220CPS (Cycles Per Second) "A" up to a 660CPS high "E" . Each rigid toilet tube was connected to an elastic hose of equal length. The hoses were connected to a manifold to supply water to all of them.
In one prototype embodiment, which I built into a Jacuzzi-style bath tub in my bathroom, I used Schedule 160 stainless steel pipes. of various lengths, to create a natural hydraulophone scale (110 CPS "A" through 330 CPS "E" ). The lenghts of the pipes ranged from approximately 12 inches (approx. 305cn1) for the low A
down to approximately 4 inches (approx. 102cm) for the high "E". The very rigid Schedule 160 pipes were supplied by elastic hoses.
In some embodiments, a one or more hydrophones (or underwater microphones) listens to the sound made by the vibrating water. The outputs of the hydrophones are electrically amplified, and sometimes various auditory effects processors are used, or other processors are used to generate other multimedia effects, not necessarily limited to auditory effects.
In another embodiment of the invention, a user-interface comprises a dozen or so 3 inch pipes (approx. 76crn in nominal diameter), of various lengths, each connected to an identical rubber elastic medium, each of which has a filling nipple. The pipes are supplied by a gentle strea.rn of water that maintains a meniscus that is concave downwards. The instrument is played by slapping the meniscus with the palm of the hand. The resulting shockwaves, water-hammer. or the like, sets a column of water into transient disturbance such that it settles into an oscillatory motion that decays exponentially, like that of 'a struck string oil a piano. Oscillations occur due to the interaction between the capacity to hold a mass of water in the pipe, and the elasticity of the end cap on the bottom of each pipe.
I made another prototype from flushometer diaphragms that oscillate at a, specific frequency with a specific amount of water column above each one, played, again, by =I

slapping the water directly on its end point. It is possible with the instrument to cup the hands in various ways to bend the pitch up or down a little bit, as well as to attain a wide variety of different sounds from each finger or hand hole.
In another aspect of the invention a separate hydrophone is used to pick up the sound made by each sound-producing element. This allows, for example, separate signal processing for each note, or separate amplification for each note so that the sounds can be distributed throughout a waterpark or public art installation.
In another embodiment of the invention, the entire instrument is cast from one piece of concrete. and the elastic mechanisms consist of water reservoirs. of cross-io section that is significantly larger than the pipes leading from the finger or hand holes. In this way, the elasticity is due to the small but nonzero compressibility of the liquid.
In another embodiment of the invention, the elastic element consists of a similar large bulbous reservoir housed in an elastic material, such that a portion of the elasticity is due to the small but nonzero compressibility of the liquid, and a portion of the elasticity is due to the material housing the liquid. I made some prototypes.
for example, from recycled plastic or glass drink bottles. Other embodiments of the invention are made from one large piece of material, such as a TIG (Tungsten Intert Gas) welded frame, from which surplus fire extinguishers are suspended. the fire extinguishers being cut shorter or longer and TIG welded back together, in various sizes. and suspended from their hydraulic+idiophonic nodal points.
Alternatively, the entire instrument may be molded front or made of a single piece of plastic. This facilitates low-cost mass production.
In another aspect of the invention, notes are changed by changing the length of the pipes, their diameter (both of which affect the capacity) and the spring or elastic mechanism or the like.
In another aspect of the invention. each finger hole of the instrument leads directly to a column of fluid, such that pressing the finger deeper into the finger hole shortens the column and increases the resonant frequency of each note, thus allowing greater musical expressivity.
Some embodiments of the invention are entirely acoustic. Other embodiments are merely user-interface devices. Many preferred embodiments use acoustically generated sounds as input to effects such as computerized processor or the like, in such a way that the overall instrument is not an electronic instrument but is more akin to an electric guitar or other acoustically-originated but electrically amplified instrument.
On professional hydraulophones for concert performance, the water jets are often arranged like the keys on a piano, and the instrument is played by pressing down on one or more of the water jets, one for each tone of a diatonic or chromatic scale. In some embodiments there is one acoustic sounding mechanism inside the instrument for each finger or hand hole or other user-interface port. Whenever a finger taps on io the water bubbling out of the UI (user interface) port, sound is generated.
A preferred embodiment of the hydraidophoiie consists of a housing that has at least one hole in it, through which water emerges. trickles, or sits. The hole and the water in it comprise a user interface, and by tapping one's fingers or palm on or near the hole, one can intricately create sound, and expressively vary the dynamics, timbre, and pitch of each note.
Besides the normal way of playing music on such a water-hammer piano, the instrument's water jets can be used simply as a user-interface and controller for other multimedia devices or other devices.
Multiple water-hammer instruments can be arranged in a two- dimensional array, or in a row., to control multiple multimedia events.
Some embodiments of the water-hanmier instrument bear similarity to an electric guitar, in the sense that the sound is initially generated acoustically, and then there is electric processing, filtering, and amplification to increase the range of sounds but maintain a high degree of expressively and intricacy of musical nuance that arises from the initially natural physical acoustic sound production. As with electric gui-tar, the new instrument of the invention can be used with numerous effects pedals, computerized effects, guitar synths, hyper instruments, and the like, while remaining very expressive. Particularly when playing the water-hammer piano underwater, at high sound levels, as with an electric guitar, feedback can be used creatively, to get long or infinite sustain in a way that is similar to the way in which notes can be held for much longer on an electric guitar than is possible with an acoustic guitar.
Some embodiments of the invention use one or more active "hydrospeakers"
(trans-(3 mit hydrophones, i.e. speakers designed for use underwater) built in, in addition to the "receive hydrophones" (underwater microphones) of the pickup. In much of the liter-attire, the term "hydrophone" means a transducer that can send and receive, whereas similar transducers in air are described by the words "microphone" or "speaker" for receive and transmit, respectively. I prefer to use the tern "hydrophone" to denote underwater listening transducers, and "hvdrospeaker" to denote underwater sound-producing transducers, in order to disambiguate in applications where the device only sends or only receives.
The underwater hydraulophone with acoustic pickup is also useful for creative use of acoustic feedback, and various interesting forms of interaction with sounds pro-duced in the water, especially if one or more hydrospeakers ("transmit hydrophones") are installed inside the instrument.
In sonic embodiments the output from each microphone is run into a bandpass filter, tuned to the frequency of the note corresponding to that particular user interface port.
By cascading a variety of different filterbanks. sonic embodiments achieve a rich and full sound that is still very expressive, but is easier to play.
When using hydrophones to listen to the sound from inside the vibrating water, the hydrophone caii dampen the sound, so it is best to use a hydrophone of low "dampiness", i.e. a hydrophone that doesn't rob the instrument of too much sound.
A peizoelectric cylinder encapsulated in a sufficiently rigid polymer will work. Prefer-ably the polymer has an acoustic impedance similar to water, such that there is only one transition zone from into and out of the peizoelectric material.
Alternatively, a graded-impedance layer of variously designed encapsulations, one on top of the other, may be used. In either case, loss should be avoided, and the wire to the hydrophone should also be selected so that its insulation is not acoustically lossy.
In some embodiments, to further increase the playability an acoustic exciter, such as one or more hydrospeakers, is placed inside the instrument, causing feedback to occur. When combined with a bank of bandpass filters, this results in a tendency for the instrument to favor playing at or near the center frequency of each bandpass filter. As a result of this feedback, the instrument becarnes alot easier to play "on key", but still is sufficiently expressive (i.e. there is still sufficient ability to "bend"

and sculpt notes).
In other embodiments a soundboard is used. The soundboard is connected to the reservoirs. For example, the reservoirs may each comprise an Erlentneyer flask or flat-bottom bottle. A plastic folding table. such as the standard folding tables sold in home improvement centres, works quite well for this purpose. Bottles sitting on the table tend to radiate to the table's surface.
Alternatively, aluminum sounding plates may be TIG welded to the bottom of each of a plurality of aluminum bottles constructed from scrap aluminum fire extin-guishers. The carbon dioxide and dry powder are eruptied, and the empty canisters io are modified into the desired size and shape. The sounding plates extend past the round bottonis of the variously modified fire extinguishers, and both radiate as well as absorb sound from the surrounding air, and conduct this sound into the bodies of the fire extinguisher metal, and subsequently the water contained therein.
The soundboard provides two useful functions: (1) it radiates sound from the 1s vibrations in the chamber into the surrounding air; (2) it allows sound in the sur-rounding air to affect the vibrating water. This second use helps when trying to create acoustic feedback.
The meniscus of water rests statically or emerges slowly from each mouth, waiting to be struck by the palm or other body part such as the foot of the user (e.g.
there 20 can be hand division like the manuals of a pipe organ and foot division in ground nozzles like the pedal division of a pipe organ). This ineniscusial user-interface allows the user to interact with water and abruptly set it iltto vibration.
Specialized embodiments of the invention for physiotherapy and wellness:
The invention may be used for water therapy, as part of therapy pools, physio-25 therapy, music therapy and in health and wellness centres.
The invention may have a basin that captures and recirculates water emerging or gently brimming over each of the mouths.
The user of the invention may be seated in the basin, such as, for example, by making the basin be a hot tub or jacuzzi or therapy pool. One or more persons 30 may communally enjoy being in the basin while one or more of the bathers use the apparatus of the invention.
The invention may be used for entertainrneut, relaxation, or training exercises, or the like, or in a spa or aquatics facility, waterpark, or playground for entertainment, relaxation, exercise, or training.
The invention may include an element for providing tactile stimulation. Such an element is sometimes referred to herein is a tactor. As used herein, a tactor is a type of transducer which converts an electrical signal to a variable tactile stimulation and which may also he capable of converting a tactile stimulation to an electrical signal.
The tactor may be a vibratory transmit hvdrophone in the water, or in each mouth of the instrument.
In some embodiments of the invention. brainwave entrainment may be used to io create a relaxation or mediation environment. The tactor may vibrate in a repetition rate in the 1 to 30 CPS (Cycles Per Second) range. The actual frequency of vibration need not be in that range, but some aspect of the waveform such as the repetition rate of tone-bursts can be placed in that range for use in brainwave entrainment.
A headband worn by the bather may thus be used to modulate the entrainment frequency of the device when used in these kinds of physiotherapy or the like.
More generally, brainwave entrainment need not be limited to sinusouidal signals of pure tone., but, may instead comprise spread spectrum excitation, or other arbitrary periodic or quasi-periodic signals that can be worked with the equivalent of a more generalized lock-in amplifier.
A standard lock-in amplifier such as a Stanford Research SR510 lock in amplifier can be used for sinusoidal signal detection. For example, we might excite the user at a particular frequency and then attempt to coherently detect the existence of that fre-quency in the subject's brainwaves. However, a better approach is to entrain desired brainwave activity more generally, with an arbitrary periodic excitation, and then measure, more generally. the response to this very excitation, with signal averaging, or the like.
Tactile and audiovisual entrainment. biofeedback, or the like. are constructed such that thalmic stimulation of the cerebral cortex affects cortical activity, in a frequency range around 1 to 30 CPS over a large area of the body such as by vibratory elements or other tactuators in, seating, pulsating hot tub jets, as well as audiovisual stimulus.
Television can have a sort of hypnotic effect on the watcher, thus causing different brain states to be reached. Similarly, a computer screen can be directed in a more structured way, as part of a biofeedback loop, especially in the context of a relaxation tub, relaxation application, or for exercises for the mind and body.
Various forms of SSVEP (Steady State Visual Evoked Potentials may be displayed on a multimedia display device, or, alternatively, upon illumination sources in the s finger or hand holes of the instrument, by way of illuminating each of the water holes separately. In this way, one or more senses can be stimulated for brainwave entrainment while part of an exercise or gain(, or training or relaxation regimen is in process.
Some embodiments of the invention may use tactile sound, so that the device is io more than simply all input device.
Frequencies up to a couple hundred CPS may be felt by the fingers if sufficiently strong in their vibrations, as can be achieved by way of, for example, a suitable tactuator such as the Clark Synthesis AQ339 geophone or hydrophone sometimes referred to as an "Aquasonic Underwater Speaker" , although it is more of a geophonic 15 or hydrophonic device than a loudspeaker (i.e. it is meant to move solid matter or liquid matter more so than to move air).
In applications where the use is not underwater, but outdoors in light rain, or in a somewhat dry housing, a Clark Synthesis model AW339 will suffice.
The result is "tactile sound", i.e. a sensation of sound sent to the human body zo directly in liquid or solid matter, rather than through air.
In communal bathing areas like one might find at a place like Spaworld USA, the "tactile sound" can be felt without too much disturbance to other bathers using adjacent therapy equipment.
In a hot tub, even a communal hot tub or spa, tactual vibration of one individual's 25 body can be achieved without too much disturbance to others. if desired.
Baseband versus narrowband sensing:
A simple embodiment of the invention comprises a row of a dozen or so bottles that are filled with water, by a source that slowly fills each bottle and thus makes all the bottles gently runneth over. Each bottle has hydrophone, such as a Sensortech 30 model SQ34, in the bulb part of the bottle. Each hydrophone is connected to an amplifier input, whereupon the instrument is played by striking or tapping the open mouths of the bottles to make a nice pure sound which sounds similar to that made by a Fender Rhodes electric piano (i.e. similar to the sound made by striking a tuning fork tuned to each note). The sound is very pure because the bottles form Helmholtz resonators that each tune to one and only one frequency with very little in the way of overtones or higher harmonics beyond the fiurdaniental.
The best way to play the instrurnent is to strike the meniscus of the water.
This meniscusial user-interface allows for a great deal of nuance. Additionally.
the in-strument can be played by tapping the edjes of the necks of the bottles. with the fingertips, in a downward motion.
An alternative form of listening device is pressure sensor or diaphragm sensor, io such as made from a peizoresistive diaphragm having a Wheatstone bridge, supplied with a power source such as, for example, a 12 volt power supply. Preferably the 12 volt supply is center-grounded, with +6 volts going to one side of the bridge input and -6 volts to the other. The bridge output, is connected to a balanced XLR
microphone plug (Switchcraft A3NI) or a balanced quarter inch plug, or an underwater connector.
Such a pressure sensor or diapliragnr sensor is placed such that one side of each diaphragm listens inside each bottle, and the other side is referenced to atmosphere.
In this way, the sound can be heard all the way down to, and including a frequency of 0 CPS, i.e. DC (Direct Current).
This combined "AC DC" capability means that the sensor can hear the bell-like sound of striking the water, as well as feel the sustained pressure if exerted in a sustained manner. The sensed pressure can be frequency-shifted to match the resonance of the bottle, and in this way, hitting the water makes a chime, and pressing and holding down on the water makes an organ sound.
Since the diagphragm sensor can listen to AC and DC, the result is a "PIANOr-gan" (a portmanteau of the words "piano" and -organ'"), or "guiolin" (a "guitar" and "organ").
The low-frequency sensing that goes right down to 0 CPS is called baseband sensing. and the resulting signal is called a baseband signal. It is generated by pressing the palm down on the mouths of one of the bottles and holding it down. As long as you keep it held down, the pressure in the bottle remains higher than it was before.
and the pressure sensor continues to output DC.
The sound made by striking without pressing is an AC signal that is called a passband or narrowband signal.
Combining the narrowband and baseband signals can work with the bottles when fitted with a diaphragm sensor that does double duty listening to the AC and DC
Alternatively, since many diaphragm sensors are not very sensitive, or of limited dynarnage range (i.e. are damaged by heavy water hammer if they are made to sensitive), it may be preferable to use one sensor for the AC and one for DC
and thus have a small-signal sensor and a, large-signal sensor. A suitable DC large-signal sensor is a diaphragm sensor or pressure sensor such as is connnonly used in process control systems. A suitable AC small-signal sensor is a. Sensortech model SQ34 hydrophone.
Together these two sensors, one for each bottle, will give a better result than using the diaphragm sensor alone.
When using bottles, the elasticity arises from the large volume of water, and water being slightly compressible yields when presented in a sufficiently voluminous reser-voir. The bottle's own elasticity may or may not also contribute, depending on the wall thickness of the bottle (for example, encasing the bottles in cement makes them follow theory better, and thus easier to compute using the standard Helmholtz for-mula). Additionally, backing the bottles in cement helps prevent them from breaking due to excess forces and transient forces. One embodiment uses variously sized Bor-Beaux wine bottles or Florence flasks encased completely in cement, except for the mouths of the bottles, each bottle having two additional holes, one for a continuous water supply, and another for a listening device to listen to the vibrations in the water itself. The Bordeaux wine bottles. or Florence flasks, or the like. may be cut to different lengths using a bottle cutter. and then welded together using glass working techniques.
Vuine bottle cutters are well known in the art. More durable bottles can be made from stainless steel spheres TIG welded to stainless steel pipes. An easy way to get stainless steel spheres is to obtain floats made out of stainless steel. These spherical floats are readily available. and can be TIC welded to a stainless steel pipe, after knocking a hole in the sphere using a plasma cutter. A suitable process for manufacturing the hydraulophone bottle is to use a. plasma cutter, such as Miller Spectrum 375 X-TREME(TM), to cut a hole in a stainless steel float. A suitable size of float is one that is in the 3 inch (approx. 75nmi) to 9 inch (approx.
230mm) diameter range. A pipe is then TIC welded onto the ball to make a hydraulophone bottle. A satisfactory welding process is the use of a Miller Dynasty 350 that has been modified from the standard 14 pin control connector to the 28 pill welding automation connector, for use with a robotic orbital welder, to automate the process of TIC welding the pipes onto the balls. A weld current is delivered at high amperage and low frequency while a 2% Thorium tungsten electrode moves toward the pipe, and the weld current is reduced and the frequency is increased while the electrode moves toward the float, which is typically of thinner material.
A satisfactory size pipe is a schedule 40, size 6 (1 inch nominal, approx.
25.4mm nominal, having approximately 1.315 inch outside diameter) pipe for some of the medium notes on the instrument. A size 7 or 8 pipe is suitable for the lower notes, and a size 5 (this is called "three quarter inch pipe" and is approximately 1.05 inches or 26.7mm outside diamter) is suitable for the higher notes.
Alternatively. instead of using bottles for the hydraulophone pipes, the hydraulo-phone pipes may each be made from a rigid pipe fitted with an elastic end medium on the bottom of each pipe. A satisfactory clastic medium is the diaphragm from a Sloan Valve model LC (which stands for "Low Consumption'') flushozneter.
Thus a very nice waterhammer piano may be constructed from a dozen or so Sloan Valve LC flushozneter diaphragms fitted onto the bottoms of pipes of various lengths, the lengths determining the notes of each of these hydraulophone pipes.
Instead of using the flushozneter diaphragms, a thin stainless steel "bender"
may be TIG welded to the bottom of each of a plurality of stainless steel pipes to get the elastic medium.
A simple variation of this embodiment arises by way of using a peizoelectric "ben-der" transducer as the end cap for the bottoms of each of the pipes. In this way the bender does double-duty as both a spring and a sensor.
Alternatively, some kind of strain guage may be affixed to each pipe bottom.
Thus the pipe bottoms themselves become diaphragm sensors.
Suppose each of a dozen pipes is fitted with a strain guauge resistance bridge, at its bottommost point. One input to each bridge is supplied with a voltage supply such as +6 volts, for example, and the other side with -6 volts. The dozen or so pairs of outputs are connected to instrumentation amplifiers that can listen to the sounds of the vibrating water as well as listen to the baseband pressure if, for example, pressing and holding the palm of the hand onto the mouth of the hydranlophone pipe.
Alternatively The dozen or so bridges can be matrixed in a 3 by 4 arrangement, to use 3 of the 6 analog inputs of an Atrnel ATNIEGA48 for example. The bridges are supplied by voltage from output pins PB1, PB2. PB3, and PB4 of the AT-NIEGA 48, as referred to the Atrnel ATMEGA 48 datasheet, or the pinout diagram, which can be obtained from Atinel Corporation or there is also a local cache in,vr/.
Were more factors are present, we simply use more pins, e.g. PBO-7 driving a 6 by 8 set of matrixed bridges into all six analog inputs provides 48 bridges, so that we can then have 48 hvdraulophone pipes, i.e. 48 water holes, analogous to it piano with 48 keys.
The output of each of the 12 bridges (one for each water hole) may be connected directly to pins PCO-PC2 (refer again to Atrnel ATMEGA 48 datasheet for PCO, PC1, PC2, etc., pinout designators), for simplicity.
Preferably, though, we connect the two outputs of each bridge (i.e. left and right) to a differential instrument op amp (operational amplifier) and the output of that op amp is what is actually connected to the input pins PCO-2. Because of the matrixing, for the 12 diaphragm sensors, we only require 3 op amps for 12 sensors, rather than requiring 12 op amps.
Pressing the pahn and holding down on one of the water holes decreases the resistance of one path of the bridge (i.e. increases the conductivity, of one path of the bridge thus pulling the output voltage of the bridge in one direction. The bridges are normally wired so that this direction results in more positive output of the positive output of the bridge with the other side going more negative, such that a differential op amp connected to the bridge output gives a higher output.
Thus pressing down on one water hole causes a measurable output for that par-ticular corresponding bridge. that indicates pressure. Resistance bridges are in some ways analogous to a carbon microphone, and can "hear" sounds and other distur-bances made in the water, in addition to slow flexing. Thus the bridges pick up a frequency range that goes all the way down to 0 CPS. i.e. Direct Current (DC).
In this sense, the sound spectrum that the bridges "hear" includes the origin, in the frequency axis.
In addition to flexion, in some einbodiments, we have one or more AC
hydrophones in each pipe that listen to vibrations in the water. AC hydrophones such as the Sensortech SQ34 tend to pick up higher frequencies better, and they can also "listen"
and "speak" , i.e. they can create disturbances when fed with electric input.
Another suitable hydrophone is the previously mentioned Clark Synthesis AQ339 geophone or hydrophone.
It is helpful to classify transducers according to state-of-matter in which they operate:

= solid: geophone;

= liquid: hydrophone;

= gas: loudspeaker or microphone:
= plasma: ionophone.


The invention will now be described in more detail, by way of examples which in no way are meant to limit the scope of the invention, but, rather, these examples will serve to illustrate the invention with reference to the accompanying drawings, in which:
FIG. 1 illustrates an embodiment of the invention having a basin, heater, and recirculating pump, suitable for being, or being installed in, a hot tub, or the like.
FIG. 2 illustrates a bottle piano embodiment of the invention.
FIG. 3 illustrates an AC, DC (Alternating Current, Direct Current) embodiment of the invention in which subsonic (or DC) sounds in a bottle are used to modify the audible sounds in the bottle.
FIG. 4 illustrates a bottle piano embodiment of the invention setup with 12 bottles on a musical scale.
FIG. 5 illustrates a tuning inethod for the bottle piano embodiment.

FIG. 6 illustrates an embodiment having closely spaced mouths.
FIG. 7 illustrates all embodiment where the DC channel is implemented by a fipple circuit that is completed by the touch of a finger or the like, to a playing interface.
FIG. 8 illustrates an AC/DC arrangement by way of analogy to FIG. 9 illustrates an embodiment of the invention that uses a shifterbank to eliminate the need for the different bottle sizes, or the need for bottles altogether.

While the invention shall now be described with reference to the preferred em-io bodiments shown in the drawings, it should be understood that the intention is not to limit the invention only to the particular embodiments shown but rather to cover all alterations, modifications and equivalent arrangements possible within the scope of appended claims.
In various aspects of the present invention, references to "microphone" can mean any device or collection of devices capable of determining pressure, or changes in pressure, or flow, or changes in flow, in any medium.
Likewise the term "hydrophone" describes any of a variety of pressure transducers, pressure sensors, or flow sensors that convert changes in hydraulic pressure or flow to electrical signals. Hydrophones may include differential pressure sensors, as well as pressure sensors that measure gauge pressure. Thus a hydrophone may have a single "listening" port or dual ports, one on each side of a, glass or ceramic plate, stainless steel diaphragm, or the like. The term "hydrophone" may also include pressure sensors that respond only to discrete changes in pressure, such as a pressure switch which may be regarded as a 1-bit hydrophone. Moreover, the term "hydrophone"
can also describe devices that only respond to changes in pressure or pressure difference, i.e. to devices that cannot convey a static pressure or static pressure differences. More particularly, the term "hydrophone" is used to describe pressure sensors that sense pressure or pressure changes in any frequency range whether or not the frequency range is within the range of human hearing, or subsonic (including all the way down to zero cycles per second) or ultrasonic. Similarly the term "geophone" is used to describe any kind of "contact microphone" or similar transducer that senses or can sense vibrations or pressure or pressure changes in solid matter. Thus the terra "geophone" describes contact microphones that work in audible frequency ranges as well as other pressure sensors that work in any frequency range, not just audible frequencies.
The terms "Earth", "NVater", "Air" and "Fire" refer to the states-of-matter.
For example. the Classical Element indicated by the term "earth" refers to any solid matter. Likewise the term "water'' refers to any liquid such as wine, oil, hydraulic fluid, or the like. The term "hydraulic" also refers broadly to any pressurized or pressurizable liquid not just water. The Classical Element of "air" likewise refers to any gas, etc..
The method claim(s) is/are meant to be taken in the broad sense, e.g. a method of making music with water by filling bottles and then putting a listening device inside each bottle is to be taken as the same method as putting the listening device in first and then filling lip the bottles.
FIG. 1 illustrates an embodiment of the invention having a basin 100B, a heater 100H, and a recirculating pump, 100P. This embodiment is suitable for being, or being installed in, a hot tub, or the like. Water from basin 100B is drawn into pump 100P where it passes through heater 100H to feed manifold 10011-1, which feeds one or more water supply lines lO1S, 102S, ..., etc..
The one or more water supply lines feed one or more user-interfaces 101U, 1O2U, etc., by way of one or more supply pipes 101P. 1O2P, ..., etc..
The one or niore supply pipes are typically rigid pipes, denoted by the thick vertical lines in the drawing, because one means to make a pipe rigid is to make it from relatively hard and thick-walled material, such as thick-walled Type 316 stainless steel. or the like. Plastic pipes may be used in some embodiments. if the pipes are thick enough, and especially if they are backed by some rigid material such as cement, concrete, or the like. especially in an inground pool or inground hot tub where concerto is typically used.
The water within the pipes 101P, 102P, ... typically has a carefully selected mass that is linearly proportional to the length of the pipe. The speed of sound in water is about four and half times faster than in air, and the instrument of the invention often tends to produce lower notes, so in many embodiments of the invention we can neglect the time it takes sound to travel front one end of pipe 101P, 102P....
to the li other, and consider the mass of water in the pipe as a single vibrating mass.
In this case, we approximate the vibrations in the water as being uniform along the pipes 1O1P, 102P, ....
I shall refer to the product of the density (mass per unit volume) of the water and the length of the pipe, divided by its cross sectional area, as "capacity" or "capaci-tance", and to this body of water itself as a "capacitor".
I use the terns "capacitor" as a variation Oil the forCC-currentt analog commonly used in control theory. For more reading on this analogy, see, for example, Control Systems, by Naresh K. Sinha, John Wiley & Sons, Hardcover, 488 pages, July 1995, io ISBN-l0: 0470235160, ISBN-13: 978-0470235164. The force-current analogy creates an analogy between rnechancial systems and electrical systems in which capacitance is analogous to mass, inductance is analogous to inverse spring constant (i.e.
a coil of wire is analogous to the coil of a spring with inductance in Henrys equivalent to inverse spring constant of the spring), and voltage is analogous to velocity, etc.. Note that this analog theory differs from an earlier analog theory of James Clerk Maxwell in which voltage is analogous to force and current is analogous to velocity.
Maxwell's version is called the force-voltage analogy. One advantage of the more recent force-current analogy is that voltage and velocity are both across variables (e.g.
measured across two different points, such as when you stand on a moving train and watch another train go by, you're measuring relative velocity, as when you put a voltmeter probe from one point to another point), and that current and force are both through variables (i.e. force and current both occur at a single point).
We use a variant of the force-current theory in which capacitance is mass divided by distance to the fourth exponent, rather than letting capacitance stand for mass alone. This proves convenient in terns of factoring in the diameter of the user port (pipe 1O1P or 102P, or the like).
The capacitance of the pipes IO1P, 102P, ... is thus, C = l (1) where p is the density, typically in units of ky/r11 '1.
Capacitance, C, of Equation 1 is in units of kg Sal na = ky~7rrr.
2 (2) 7T 1, When the finger holes or user-interfaces 101 U, 102U, ... are struck, touched, pounded or slapped, the capacitance of water in the rigid pipes 101P, 102P, ... vibrates or oscillates due to the combined effect of the capacitance as described above, and an elasticity, lasticity. or elastic or lastic member, such as spring lOlL, 102L, ....
In the Fig. 1, the lastic members are depicted as springs. These can take the forms of flexible rubber hoses, one connected to each of the pipes 101P, 102P, ....
For example, supply lines IOIS, 102S, ... can each form one of the springs lOlL, 102L, ... if made of sufficiently suitable elastic, elastomeric. or lastic material.
In other embodiments springs 1011, 102L, ... comprise bulbs of water. Each of the springs is implemented as a bulb of water, wherein the compressibility comes from the compressibilty of the water itself.
It is interesting to note that when I was inventing the hydraulophone, many ex-perts in fluid mechanics discouraged me by telling me it was impossible to make an underwater musical instrument because water is not compressible. But despite the ,5 fact that people often refer to liquids as incompressible fluids, we should really say that liquids are less compressible fluids, when compared with gases. The fact remains that liquids are slightly compressible, i.e. there is some degree of compressibility, [3 = 1 /Ii which is nonzero.
In operation. the instrument of Fig. 1 presents the user with user-interfaces 1O1U, 102U. ... numbering typically 12 interface holes on a diatonic scale covering a 1.5 octave range. In some typical embodiments there are 19, 33, or 45 user-interface holes, in keeping with the traditions defined by steady-state flow-based hydraulophones, although any number of holes from 1 and up, are possible with the invention.
In some embodiments, stemming from each hole is a meniscus 1O1M, and the instrument presents the user with a meniscusial user interface in which the user slaps the meniscus to create disturbances in the water.
Slapping the entire meniscus creates an explosive water-hammer sound, whereas hitting half or less of the rniniscus creates a softer sound because it allows some water to escape while being struck.
It should be noted that the instrument responds to how hard and fast it is struck, as does a piano, but that there are further degrees of freedom as to how the meniscus is struck.

For example, you can hit the whole tiring gently, or just a little bit of it very firmly. In both cases you can arrange it so the total sound level is identical in terms of how loud it sounds, but hitting it near the edge gives a more pure bell like quality whereas hitting it dead center and wholly gives it a more harsh and explosive kind of sound.
The sound in the instrument is produced bi- vibrating water. The vibrations in the water are very forceful but travel through small displacements. Thus to make them audible in a large concert hall. for example, it is preferable to have some kind of impedance transformation, such as by way of transformers 101T, 102T, ....
The transformers 101T, 102T, ... may comprise pressure chambers similar to those found in an old Edison style phonograph, each supplying a horn. Thus the instrument, might have 12 horns, each one made specifically for a specific note. As such the horns may each be optimized for the particular note they are made for, such that there is a large horn for the lowest note and a small horn for the highest note, and various sizes in between.
Alternatively, transformers 101T, 102T, ... may be constructed with hydrophones (underwater listening devices) connected to an electric amplifier and loudspeaker.
A satisfactory hydrophone is a Sensortech SQ34 hydrophone connected to an audio amplifier having a sufficiently high input impedance.
In some embodiments, it is preferable to feedback some of the electrically amplified signal to the springs 101L, 102L, ... to increase the sustain of the instrument,. A foot pedal may be supplied to dampen this feedback, and/or mechanically dampen the springs, much like the damping pedal of a, vibraphone.
FIG. 2 illustrates an embodiment of the invention in which springs 101L, 102L.
... are bulbs of water. The water itself forms the spring. Although liquids are often said to be incompressible fluids (researchers often refer to gases as compressible fluids and liquids as incompressible fluids) there is some nonzero degree of compressibility that liquids posess, even though the degree of compressibility is very small.
Let the degree of compressibility of the fluid, such as water, be denoted by C3 =
- ~l, dV/dp. We prefer to use the incompressibility which is the reciprocal of the compressibility: K is the incompressibility given by K = -Vdp/dV, which is more like the familiar "spring constant".

The elastic medium of Fig. 2 is specifically a bulb of liquid, and if the walls of the bulb are inelastic, let us denote the elasticity, lasticity, by the letter "L", as in elastic, or buLb:
L=V/K=Vj (3) Let us define this value, L as being analogous to inductance. It has units of:

3 s2 (4) kg kq 711s2 The resonant frequency of each note is given by:

f (5) 2~r LC

In the case of an inelastic bulb, this is approximately:
f 7 Vl (6) where c is the speed of sound in the water, c A is the area of the user-interface or neck, l is the length of the neck. and V is the volume of the bulb.
This inelasticity can be approximated by encasing the bulbs in concrete to make sure they don't offer much, if any, springiness in and of themselves. In one embod-y invent I encased variously modified (i.e. variously sized for various notes) Bordeaux wine bottles in concrete, to make a set of hydraulic resonators which I
refered to as "Nessonators""" The word Nessonator is a word I made up from the words "Nessie" (as in the giant sea snake said to inhabit Scotland's Loch Ness) and "res-onance". The name "Nessie" is a trademark that I have been using for my aquatic to musical instrument inventions, and I have sold these under the name "NessicT~'r"
A Nessonator (hydraulic resonator) can be made from a rigid pipe connected to a rubber hose, or from a rigid pipe connected to an elastic bulb, or from a rigid pipe connected to a rigid bulb, or from a rigid pipe connected to a diaphragm. or from a wide variety of other means.
15 When the Nessonator is rigid, such as can be approximated from a concrete bottle, we get a philosophical purity in the instrument, in the sense that the sound comes primarily (or wholly) from vibrating water. that has very little (or no) influence from the materials from which the instrument is made.

I call such an embodiment a waterflute, to distinguish it from an instrument that makes sound from vibrating water in conjunction with vibrating solid matter.
Embodiments of my invention that use a combination of vibrating water and vibrating solid matter might aptly be called "hydraulidiophones", a portmanteau of "hydraulophone" and "idiophone". In selling such instruments I use the tradenames "CLARINessieTM', (analogous to a clarinet which makes sound from vibrating air in conjunction with vibrating solid matter of a reed), and "H2OboeT` I,,, (hydraulophones that have more than one reed associated with each finger hole).
A 12-jet CLARINessieTM thus has 12 reeds, whereas a 12 jet H2OboeTM typically io has 24 or 36 reeds (2 or 3 per finger hole).
When the bulbs for springs TOIL, 102L, ... are made of material that is not rigid, the instrument behaves partly as a waterflute, but also exhibits features similar to that of the CLARINessie. Embodiments of the invention can also be made from pipes themselves that are somewhat elastic, or from joining elastic to inelastic pipes, or the like.
Whether the bulb is rigid, elastic, or whether there is no bulb at all (i.e.
where the springs are elastic disks; cylindrical slugs, rubber hoses, or otherwise, we may continue to use Equation 3 but with a modified value of L analogous to the "equivalent inductance" that defines the resonant frequency f = 2,7 117C*
_ Referring once again to Fig. 2, pump LOOP pumps water (possibly through heater 100H if present) to a. bottle supply manifold LOOM, from which supply lines I01S, 1025.... keep the bottles of the underwater bottle organ topped up. Springs lOlL.
102L, ... are the bulbs (bodies) of the bottles, and pipes 101P, 102P, ...
form the necks of the bottles.
If the bottles are encased in concrete. or simply are concrete, then they can be suspended by any part of the bottle, typically. However, if the bulbs are elastic, then they should be suspended as may be achieved by grasping the bottles by their necks, with bottle clamps 201C, 202C.....
Clamps 201C, 202C, ... may be retort clamps, or they may be simply a means for 3o holding the bottles, such as by welding the bottle necks to a metal plate when the necks are made of metal.
Each bottle has a transformer 1.OIT, or 102T, or ..., positioned near the center of its bulb.
A non-damping bottle holder as described above, or as facilitated by other means, is kind of like the way a glockenspiel or rrretallophone has the metal bars or pipes held at the nodal points. If the bottle is in fact idiophonic, then a non-damping bottle holder should grasp it in such a way as to be grasping it at or near its idiophonic nodal points.
When the bottle is encased in concrete, just about any mounting will be a non-damping bottle holder.
Preferably the bottles each have a bottle fill port or supply port 201S, 202S, ...
io and a listening port 201L, 202L, ....
FIG. 3 shows an AC+DC (Alternating Current-Direct Current) embodiment of the invention in which an eLastic buLb such as spring lOlL is fitted with a differential diaphragm sensor hydrophone 301H. The hydrophone 301H is a differential pressure sensor having two ports, an acoustic transformer port 301T and an atmospheric ref-,s erence port 3018,. Alternatively a flow sensor, pressure switch, or flow switch may be used, or a combination of devices, such as a hydrophone to listen, and a flow switch or pressure switch to respond to changes in flow or pressure.
Consider, for the moment, a signgle diaphragm sensor for hydrophone 301H, such as a piezoresistive pressure sensor having a thin glass diaphragm 301D fitted with 20 piezoresistive strain guages arranged in a wheatstone bridge. The bridge is supplied by a 12 volt center-tapped power supply with a grounded center tap, i.e. to supply the bridge with 6 volts. There are four conductors in cable set or wire 301W. Wire 301WW' being a 4-conductor wire or cable assembly has two input conductors from the plus minus 6 volts, and two output conductors that connect to a high gain analog 25 instrumentation amplifier 320AC. Amplifier 320AC may be capacitively coupled, if desired, so that a very high gain can be achieved without problems with DC
offset. It may comprise many stages of amplification- AC coupled (i.e. capacitively coupled).
The AC signal processing track responds to transient sounds that make the in-strument a bottle piano, i.e. to capture the percussive effects of water hammer. A
30 parallel processing path also makes the instrument simultaneously function as a bot-tle organ. Processor and amplifier 320DC capture show changes in pressure inside the bottle. The processor part of processor and amplifier 320DC frequency-shifts the DC part of the. input signal 340S from hydroplione 301H. This can be dome by a con-volution in the time-domain, or by a shifting in the frequency domain (i.e.
Fourier Transform, followed by shifting samples, followed by inverse Fourier Transform), or the like. Alternatively, the processor part of processor and amplifier 320DC
can be a voltage-controlled oscillator tuned to the same frequency as the resonant frequency of the bottle. In this way, when you press your hand on the mouth of the bottle, and hold while pressing down, the pressure in the bottle stays high as long as you hold down, and thus a tone sounds for as long as you press down on the mouth of the bottle.
Thus the instrument behaves like a. piano and an organ at the same time.
Slapping the mouth of the bottle with the pahn of the hand makes a percussive sound from resonance in the bottle. Pressing and holding makes a steady drawn out sound.
A High Dynanic Range (IIDR) signal processor 320S combines the AC ('piano-like") and DC ("organ-like") signals 340AC and 340DC. If one of the signals clips, for example, it call be moderated down in its effect, as compared to the better (i.e.
nonclipping) of the two signals.
Any number of separate signal processing pathways can be used. For example, there can be a high gain AC path, a low gain AC path, a high gain DC path, and a low gain DC path, all four of which can be combined to give a high dynamic range signal, using HDR processing with certaintly functions as described in the IEEE
Transactions on Image Processing, in an article entitled "Compa.rarnetric Equations'', in volume 9, number 8, ISSN 1057-7149, August 2000, pages 1389-1406.
In some embodiments amplifiers 320AC and 320DC are potted in resin and placed inside the bulb together with hydrophone 30111, for 2 reasons: so that they are (1) close to the source, and (2) so that they are at the same temperature is hydrophone 30111. In fact a therrnistor inside the amplifier assembly can be coupled to hydrophone 301H for temperature compensation against drift, especially useful in amplifier 320DC
where offset drift might otherwise push the output 320N into the supply rails or saturation or cutoff.
An atmospheric reference pipe 301A emerges from the bulb spring 101L of the bottle. Wiring 301W also emerges from the bottle.
Each bottle has 4 ports:

= a wiring port 310W;

= an atmospheric reference port 310A;

= a. port for supply lines 1015, 201S, ...; and = a port for the user-interfaces 101U. 102U.....

When I refer to "listening device" I refer to a device that may sense quantities ouside the range of human hearing. Much of the DC part of the signal captured by hydrophone 301H is subsonic. In some embodiments, instead of using one sensing or listening device to sense the AC and DC. we ma use separate devices. For example, amplifier 320AC may be supplied with an AC hydrophone such as a Sensortech SQ34, i0 that is not a diaphragm sensor. Processor and amplifier 320DC may be supplied with a separate pressure sensor, pressure switch, flow sensor, or flow switch that senses when a finger or hand has blocked the mouth of the bottle, and sounds, triggers, or shifts a steady note out signal output 320N for as long as the mouth of the bottle's mouth remains blocked.
We may regard the DC capabilities of the machine as an ORGAN-izer, which takes the bottle piano and makes it work like an organ, because you can slap the top of the bottle's mouth with the palm of your hand and make a very ORGAN-like sound, like a pipe organ, that keeps on sounding for as long as you would like.
In fact you could press a cork into the bottle's mouth, and walk away, and leave it for a day or two and it would still be singing when you came back, and it would keep singing until you pulled the cork out again.
Another embodiment, rather than separate AC and DC paths, is to have a rever-beration unit, such as a guitar effects pedal or other revereration unit whether it be based on something like the SAD1024 bucket brigade Charge Coupled Device type echo unit, or more like a digital delay or analog delay or tape loop or the like, just about any suitable revereration or echo unit. The reverberation unit is connected to the pressure sensor, so when the pressure increases. it captures and loops whatever sound the bottle last made or recently made.
So if you slap the bottle with your paten, it makes the sweet sound of the bottle piano, and the sound is captured in a loop that gets held for as long as there is pressure in the bottle.

The sound is bottled up in the bottle for as long as you like, and keeps echoing or reverberating until you let go, and let it escape from the bottle.
In a computerized embodiment (e.g. using a processor for the revert),, where the same processor "listens" (is responsive) to the bottle through AC and DC
signals of one hydrophone, or to separate AC and DC hydrophones), this is done, using, for example, a delay loop or echo loop, which might itself be realized, for example, using a buffer, to process and transmit the sound to a sound production system such as a speaker and amplifier system, as follows:

1. initialize loop buffer to zero;

2. begin acquiring data froth the AC cltattnel and DC channel;

3. when DC is not present, transmit the AC signal to the destination sound pro-duction system unaltered but also record or capture the sound into the loop buffer as well as transmitting it;

4. when DC is present, transmit the sound from the loop buffer instead of live from the AC channel;

5. continue acquiring the DC signal;

6. continue looping the recorded AC signal and playing it back, i.e.
transmitting it, repeatedly to the sound production system, for as long as the DC signal is present;

7. when the DC signal becomes absent:

(a) stop looping the AC signal (i.e. stop playing it back and transmitting it) to the sound production systent: and (b) restart transmission of live AC signal to the sound production system.

In some embodiments of this aspect of the invention, it is desirable to have a more fluidly continuous rather than abrupt transition between AC and DC modes. Thus what I like is to be able to tap a bottle mouth and then also press down a little while tapping, and have a nice blend of AC and DC. In some embodiments this is achieved as follows:

1. initialize loop buffer to zero;

2. begin acquiring data from the AC channel and DC channel;

3. when DC is less present, transmit more of the AC signal to the destination sound production system unaltered but also record or capture the sound into the loop buffer as well as transmitting it;

4. when DC is more present, transmit a greater proportion of the sound from the loop buffer, and a lesser proportion live from the AC channel;

5. continue acquiring the DC signal;

6. continue looping the recorded AC signal and playing it back, i.e.
transmitting io it, repeatedly to the sound production system, in proportion to the strength of the DC component of the signal.

Additionally, the nature of the AC sound loop can be varied in proportion to the DC
Alternatively, the DC input can be frequency-shifted using the AC input as a shifting signal. When I speak of DC input here. what I really mean is the subsonic sounds made by the water, including the static pressure (zero frequency) and sur-rounding low frequencies. These are not a pure Dirac Delta measure at the origin (f = 0), but, rather, spread about the origin with much energy at the origin plus some energy around the origin. This whole DC signal is then shifted up to match the AC
signal that is centered around the resonant frequency of the bottle, 1/(2rrsgrt(LC)).
Then the two can be added together or combined in other ways, such as, for example, using the DC signal to control aspects of the AC signal beyond merely the reveration described in the algorithm above.
FIG. 4 illustrates a bottle-based embodiment of the waterhammer piano inven-ts Lion. Twelve bottles 460 are held by their necks using bottle clamps 430 that suspend the bottle tops through a basin 499 where they can be struck by the player.
Typically the instrument is played by striking the meniscus of the water brimming from the mouths 400U. Alternatively, the index finger can be tapped downward onto the edge of one or more mouths 400U.

The mouths extend into the basin past a centerline 450. The centerline is the line through the centers of each neck, at the point where it intersects the basin, i.e.
the line that defines the boundary between the user-interface portion of the bottle necks, featured as protruding mouths 400U, and the part of the bottle that hangs down below the basin.
The apparatus looks like a vibraphone in some regards, in the way that the pipes hang down below an area the user interacts with. The basin 499 is generally curved on a 3 to 5 foot radius (approximately 1 to 2 metres radius), and the user (i.e. the player) stands or sits in a position that is approximately equidistant to all of the io mouths 400U.
Mouths 400U are user-interface ports that the player can interact with individually or with more than one mouth simultaneously. A utility line 490 provides concealment for water supply and electrical connections. There may be separate electrical conduit and water supply or these may be integrated. For example, a water supply may run in front of each bottle and an electrical conduit may run behind. These may be styled similarly so that the general appearance is that of a band circling around the bottles, either collectively, or individually, as an aesthetic that represents rings around, or an orbit around a planetary celestical body, or the like.
Typically line 490 is in the shape of a gentle swoosh that provides some physical support to the bottles, and also protects them to some degree. as well as providing water supply and electrical connectivity.
Inside each bottle 460 is a listening device. or listening devices. In one embodiment there is a Sensortech SQ34 hydrophone in each bottle, as well as a 26PCF type pressure sensor and signal conditioner. In another embodiment the pressure sensor is a broadband pressure sensor that listens in both DC (i.e. low frequencies that include the frequency origin f = 0) and AC (i.e. high frequencies further from the origin).
The basin is suported on legs 470. Typically the basin and overall design of the instrument is suggestive of the "Nessie" style hydraulophone, itself inspired, in shape, by the snakelike creature said to inhabit Scotland's Loch Ness.
The instrument generally has a bulbous "head" end where the lower notes (larger bottles) are located, and a more slender "tail" end where the high notes (smaller bottles) are located. The head is supported by two leg pipes, and the tail by only one leg pipe. This gives a total of 3 points of support. The instrument, standing on 3 legs, is very stable even if it is not anchored to the ground.
In a typical playground or waterpark installation, the supports are anchored in the ground and covered by a security plate 480 which also serves as a toe guard to make a nice smooth surface with the ground.
Water supply comes in through one of the supports. Another serves as the electri-cal connectivity, and a third support acts as the water drain from the basin, so that a user in a wheelchair can be parked under the instrument and not get too wet from dripping water.
In some embodiments, the water can also just overflow from the basin 499 in a way that is designed so that it runs off to the sides, and does not drip onto a user seated under the basin.
The water supply conies from underground, up one of the three legs 470. On that leg is a length of flexible hose 410 secured by pipe clamps 420 to the leg and to the water input of the utility line 490.
Hydraulophones generally keep very good time, but in exceptionally critical ap-plications, some embodiments can be user-tuned, by way of a tuning stub 401.
Stub 401 consists of a channel insert into each bulb that allows the bulb to slide up and down on the neck to fine-tune the length of the neck and thus the Capacity, C
of water in the neck. A tuning clamp 421 locks the tuning into place.
An added advantage of this arragement is that it facilitates easy cleaning of the bulbs should there be vandalism in the form of insertion of garbage into the mouths, when the instrument is installed in a public place. Clamps 421 are operable with a special security keyscrew mechanism, so that key holders can time the instrument, and clean the bulbs. Keyholders can be trusted members of the society. when the instrument is installed as a civic sculpture or architectural centerpiece. In waterparks, the keyholders can be the lifeguards or maintenance staff. In residential units, in the consumer market, a responsible family member may assume the role of tuning or cleaning the instrument.
A listening device in each bulb, such as hydrophone 440 in the largest bulb, shown (hydrophones in each of the other bulbs are present but not shown in the drawing, in order to keep the drawing simple and free of clutter) has a vent 441, which is a reference to atmosphere. The vent can be double split so that it can serve as or contain the reference to atmosphere for the hydrophone as well as the water supply to the bulb. In this embodiment the hydrophone is a type 26PCF diaphragm sensor having a programmable DC-coupled amplifier and temperature compensation onboard with an Atmel AVR, onboard with it to control it and monitor the temperature. The AVR
is thermally bonded to the diaphragm sensor to sense its temperature and compensate for offset drift that otherwise plagues high-gain DC systems. The gain is high enough to hear small-signal sounds made in the bottle as well as sense the DC
pressure and subsonic pressure waves in the bulb.
A connection 442 comes from each of the hydrophones and runs through the line 490 and down one of the legs 470, underground, through an underground conduit to a dry electrical vault where there are housed 12 AC/DC processors, one for each hydrophone. Each processor 440P receives input from an AC channel 440AC and a DC channel 440DC. The processed result is fed to a sound playback system such as a speaker system to make the instrument loud in a waterpark where there are a lot of screaming children and spraying water which makes it hard to hear the natural acoustic sound of the instrument. The electric amplification of the instrument is suitable for use in large rock concerts or large public demonstrations, or to provide a nice background sound in a waterpark where a particular child can enjoy the feeling zo of performing for the whole park while hitting water and having fun and frolic. A
sound system such as a Public Address system 440PA reproduces the sound from each of the 12 bottles throughout the waterpark, and a portion of this signal may also be used as a feedback signal 440F fed back to the instrument on soundboard 440S.
The soundingboard may be present along the bottoms of the bottles, or along any part of the bottles that resonates. The purpose of the sounding board feedback signal is to sustain the sound, much like the way an electric guitar feedback system works in a guitar such as the Moog guitar. The feedback signal goes to a feedback transducer 440FT. A satisfactory feedback transducer is a geoplione such as a Clark Synthesis Part Number AW339 tactuator.
Alternatively, flat bottom bottles may be placed on a, special sounding surface. A
satisfactory sound board is a plastic folding table. Bottles placed on such a table have an almost magical property when there is a speaker under the table that plays back the sound from a hydrophone in the bottle, while striking the meniscus of the water.
The sound feeds back into the vibrations in the bottle, causing the sound to have an almost bell-like clarity and sustain. It sounds touch like a Fender Rhodes piano (i.e.
the kind of piano made from an array of taming forks). To build an embodiment of s this aspect of the invention, you can take one or more flat bottom bottles such as Erlenmeyer flasks, and place them on a plastic folding table which is basically a thin membrane of plastic. It works best when the plastic is wet, so the bottle bottom makes an acoustic bond to the table. Alternatively, a sheet of glass can be welded to the bottom of a bottle, or an aluminum bottle can be welded to a sheet of aluminum io or the like. A speaker placed under the table (or better, a tactuator such as a Clark Synthesis Part Number AW339 can be connected directly to the table). The output of an amplifier supplies sound to the tactuator or speaker, and the input of the amplifier is connected to a, hydrophone in the bottle and the bottle is filled all the way with water, so it brims over a little bit. When you strike the meniscus of water, if the gain 15 is just right on the amplifier, you get what sounds like a tuning fork, of such pure tone, that the sound is very remarkably beautiful and pure, even though the bottle itself is far from idea. In this aspect of the invention, a relatively low quality (low "Q") bottle can be used but the result is a very high Q peak. For example, you can put an array of Coke (TM) bottles on the plastic table and time everything up right 20 and get something that sounds like a very beautiful set of tubular bells.
Then you can play "We'd Like To Teach The World To Sing" (the Coke song) on the bottles and it sounds like tubular bells or chimes. Alternatively you can fill up some Budweiser (TM) beer bottles with water, and play a Budweiser jingle on the bottle piano.
In the instrument shown in Fig 4, such sweetness of tone that results from this 25 feedback may be controlled by a sustain pedal switch, 449. Stepping down on pedal 449 closes the circuit to the feedback signal 440F to give that spiritual celestial bell-like sound. Letting up on the pedal gives a more quickly decaying sound. In the drawing of Fig. 4. the switch is shown in the closed (down) position. i.e.
with the sustain on for the nice bell-like sound, in a solid line. In a (lotted line the switch 3o position of the switch being open (pedal up) is shown.
With this pedal control, the waterhamrner piano behaves more similarly to a reg-ular piano with the use of the pedal. Alternatively, a pedal with a potentiometer can be used. For example, a standard 14-pin connector can be put on the instrument, and a standard Miller Elecric TIG welding control pedal, Miller Part Number 194744, can be used, with the wiper pin to the feedback signal 440F, the top of the potentiometer to the output of processor 440P. and the bottom of the potentiometer to ground.
Thus stepping down more on the pedal increases the feedback, and easing off a little bit reduces the feedback a little bit. Alternatively a wireless control can be used.
FIG. 5 illustrates a tuning embodiment included in the invention. This embod-iment comprises one or more bottles filled with water. Depicted in the Fig. 5 is a Bordeaux wine bottle with a flat, bottom. For feedback purposes an Erlenmeyer-i0 shaped wine bottle works even better, but the bottle shape shown in Fig. 5 comprises a working embodiment of a tuning system, as well as a satisfactory feedback system.
Tuning can be achieved by filling the bottle to varying degrees. to affect the effective neck length. The water should extend into the neck to some degree in order to get the bottle to Nessonate (i.e. to exhibit hydraulic resonance as a, water-based Helmholtz resonator). As the bottle is filled more, the Nessonant frequency decreases.
It can be tuned by filling to the correct height, and then the neck can be cut off at that height to get a ininuscus-based user-interface.
However, it is preferable to be able to fine tune the bottles without having to partially fill them, or cut the necks (or weld on more tubing to lengthen the necks) each time.
A sliding neck with telescoping tubing, one sliding into the other, is also possible.
But a better approach is to simply use an insert into the neck that occupies some space inside the neck. This will narrow the neck and lower the pitch.
Inserting it further (or inserting a bigger "space taker-upper") lowers the pitch further.
The space occupier in the neck reduces the sharpness of the Nessonance, so al-ternatively, the hydrophone itself may be used as the tuning mechanism. The reason this makes sense is that the hydrophone has to be in there anyway, so we might as well use it to tune the bottle.
The setup in Fig. 5 shows the hydrophone up in the neck, in a high position 500H.
3o A mid position 500M is shown in dotted lines. A low position 500L is also shown in dotted lines. As the hydrophone is lowered down, the pitch rises because the neck becomes free of the choke-point and widens out. As the hydrophone goes down the pitch goes up, to a point, and then lowering the hydrophone further causes the pitch to fall back down again.
There is some point of maximum pitch, where the hydrophone is between the highest and lowest points.
Tuning the bottle by raising and lowering the hydrophone is done by having it hang by its wiring, with wire holder 500W that grabs the wire and lowers or raises the hydrophone in the bottle.
A satisfactory hydrophone .540 is a Sensortech SQ34. which has a relatively high Effective Series Capacitance (ESC) of 15nF (nano Farads), and a good sensitivity of approximately -200dB (snore exact figures for Serial Number 0367 of a set of 36 Sensortech SQ34s was 15.22itF and -200.1.4(IB). The wiring 580 from the hydrophone 540 is connected to a voltage and phase controlled preamplifier as well as a processor that controls the voltage and phase of the preamplifier by way of control signal 570.
The hydrophone is connected to half of a Hosa Technology 25 foot (approx. 8 metres) gay male (i.e. male to male) balanced patch cord (i.e. TRS male on one and and TRS male on the other end), which, when cut in half, yields two 12.5 foot (approx. 4 metres) cables, having a shield, and a red and white wire. The cut end is stripped back about 12 inches (approx. 30cm) outer rubber, and back about 6 inches (approx. 15cm) inner rubber, exposing the white wire (ring) and red (tip) conductors.
The shield is cut off, and glue-shrieked (glue-shrink tubing, i.e. marine grade shrink tubing impregnated with adhesive). The white wire goes to the black hydrophone wire and the red goes to red, using smaller glue shrink (adhesive shrink tubing).
This connection results in a balanced quarter inch (approx. 6111111) plug that plugs into standard TRS (Tip Ring Sleeve) balanced quarter inch audio equipment. The ground of the amplifier 550 is connected to the shield of the hydrophone cable at the plug end only (the other end is not connected) and this ground is connected to any nearby railings or other metal parts, if they are not already bonded to the circuit ground of the apparatus. Additionally the liquid in the bottle may be grounded, if necessary, by way of an inserted grounding connection into the bottle. All materials in the bottle should be of high "Q" (i.e. low dampiness) so as not to dampen the vibrations in the water.
Audio equipment is used to amplify the hydrophone sound and feed some of that :33 sound back to the base 500B upon which the bottle(s) sit(s). Satisfactory audio equipment comprises a Peavy model 16FX mixer which has 12 microphone inputs that can be used for 12 hydrophones, one in each bottle, for a 12-bottle piano.
The output of the Peavey 16FX is connected to the input of an amplifier such as an AudioPro 3000 (3kW output power), split into a subwoofer such as a Yorkville Audio Elite SW800, and a mid cabinet such as an Elite EX401. The Peavey 16FX
together with the AP3000 and associated electronic. crossover, and an additional computer-controlled preamplifier comprise amplifier 550 which amplifies the hydrophone signal to a, speaker or speakers that comprise feedback transducer 540FT. The use of a i0 computer-controlled preamplifier allows the phase and gain of the amplifier to be dynamically adjusted to cancel or enhance feedback, in order to control the sustain and to get a nice bell-like quality from a cheap and readily available Bordeaux wine bottle. This avoids the need for more expensive Florence flasks, and also allows easier modification of a set of bottles into different sizes by using a bottle cutter to cut parts out of the bottle and change, its size in order to make a set of 12 welded bottles in a musical scale.
The setup shown here in Fig. 5 is suitable for doing a large rock concert, with a 12 bottle piano, but for a smaller demonstration of the invention, a small backpack-based battery operated speaker-amplifier can also be used to excite the base upon which the bottle sits. A satisfactory base for base 500B is a Realspace(TM) folding table, with molded plastic top, model 29Hx72Wx30D, 774491 from Office Depot, or a "Lifetime 4 ft. Adjustable Height Folding Table", model 48x24, with a table top constructed of high-density polyethylene (HDPE) plastic. The base 500B is thus the thin membrane of HDPE plastic. This behaves like the sounding board of a piano or violin, and conducts the sound from the bottle to the surroundings, as well as from the surroundings to the bottle. The table sits upon table legs that rest upon rubber safety tiles, such as 4inch (approx. 100mnr thick) SofSurface tiles.
Each tile has 64 springs in it to absorb shock and isolate the surface 500B from the ground, so that the instrument does not pickup too much vibration from footsteps or passing vehicular traffic, railway cars, streetcars, or the like.
Alternatively, a bottle clamp 5,30 suspends the bottle, and a sounding plate is used in place of base 500B. The sounding plate is a glass membrane welded to the bottom of the bottle, or it can be a piece of rigid carbon fiber, kevlar, plastic, or thin fiberglass bonded to the bottom of bottle 560. The sounding plate or sounding board board helps project the sound into the surrounding air, as well as helps to receive sound feedback from amplifier 561 by way of feedback from the ambient sound without the need even for explicit feedback transducer 500FT. In fact feedback transducer can simply be the main PA system in the concert hall or venue, and it doesn't need to specifically be under the table or base 500B pointing up, if it is sufficiently strong.
A processor 540P listens to the liydrophone and rides the volume gain of amplifier 550 up and down, to produce feedback signal 540F of such strength as to sustain feed-io back, that is filtered through the resonance of the water with the bottle.
Optionally, a phase adjustment is also dynamically made to track and maintain feedback.
A very light tap on the meniscus at the top of the bottle, or just a downward tap with the index finger on the rim of the mouth 500U, will set the resonance in motion, and begin a tone that can be sustained for as long as desired by way of the feedback.
A pedal connected to processor 540P controls this feedback process so it can range from heavily damped to infinite sustain. A satisfactory pedal is the Miller Electric Part Number 194744, or any other pedal comprising essentially a potentiometer and or switch (or both, as is the case in the Miller pedal).
The feedback processor uses a simple algorithm to keep the feedback going, if and when this feedback is desired. The algorithm proceeds as follows: check pedal;
if sustain is desired, proceed as follows:

= if pedal is depressed fully, initiate infinite sustain as follows:

- increase gain until hydroplione clipping results or is about to result (this occurs when the hydrophone signal from the vibrating water exceeds the range of linear input of the amplifier);

- decrease gain by a small increment to and monitor voltage drop;

- repeat adjustments in gain to maintain a steady-state tone for as long as the pedal is depressed fully;

if pedal eases off, decrease gain to allow any sounds to die out exponen-tially; let gain remain proportional to pedal position:

- if pedal eases off completely decrease gain completely (in the case of the 5-wire 14pin Miller pedal, the switch is used for this purpose, e.g. to shutdown the sound when the pedal backs off completely).

Not all embodiments of the invention require feedback. For example. a very nice embodiment of the invention can simply be made from a dozen or so bottles, fed into an amplifier.
In some embodiments the bottles, can also be identical, e.g. made from two six-packs of Coke bottles, and instead of having each bottle be made a different size, i0 they are pitch-shifted to notes on the scale. Suppose for example, we have a dozen identical bottles that all produce a middle "C" when struck at the top. We simply need to have 12 hydrophones, one in each bottle, and frequency shift the first "C"
down to an "A", the next "C" down to a "B", leave the third "C" as is, shift the fourth "C" up to a "D" and so on. In this way we get the natural minor scale that is typical of hydralophones. i.e. A, B, C, D. E. F, G, H (high A), I, K, K, and L
(high E).
A collection of frequency shifters arranged in this way is called a shifterbank. Thus the invention described here can be implemented using a number of bottles connected to a shifterbank.
FIG. 6 illustrates a close-fingering embodiment of the bottle piano organ, in which the necks 660C are curved or bent so that the bulbs 660L of the bottles 660 swing up and away, thus allowing the finger holes (mouths of the bottles) to be arranged more closely together. This figure shows a top view where the player 600P stands near the center 600C of the radius of curvature of the finger holes (mouths 600U).
The figure also shows a sideview of one of the bottles, the 5th bottle from the left (the 5th lowest note), which is typically note. lE using Natural Pitch Notation.
Natural Pitch Notation uses the number for the more significant digit and the letter for the less significant digit, with the more significant digit leftmost and the less significant digit rightmost. The rightmost digit counts in base 8 from A to G. The first letter of the alphabet ("A") is the lowest value for the rightmost digit, i.e. the counting begins with the first letter (not the third letter "C" ).
Bulbs 660L could have air trapped in them, so bleeder valves 660B allow air to escape when they are filled with water. Valves 660B also serve to provide a continuous supply of water into the bottles, to keep the mouths brimming over. The mouths face upward, or approximately upward, and thus runneth over with water, to form a meniscus that can be struck, tapped, or touched.
FIG. 7 illustrates an embodiment where the DC channel is implemented by a fipple or duct circuit that is completed by the touch of a. finger onto Direct Current (DC) mouth 700U which is located beneath the surface of some water, e.g. in a basin or the like. The whole bottle is submerged under the water's surface 700.
I call the mouth 700U a. Direct Current (DC) mouth because when pressed, it io causes a, steady continuous flow of water out of languid exit port 720 formed in duct 710. The duct 710 is supplied by a pump that pumps water into its input 730 that dissapears out-of-frame in the drawing (i.e. not shown). So long as a finger is pressed against mouth 700U, Water flows from left to right from input 730 through duct and out port 720 to spray across the mouth of bottle 560 to make a resonant tone picked up by hydrophone 540.
Letting the finger off mouth 700U introduces a big leak into the duct 710 allowing all or most of the pressure of the water from the puntp to escape out the top of the Bole in duct 710. The hole in the duct is mouth 700U.
Mouth 700U may extend right to the exit port 710 if desired, so that the finger can influence not just the amount of water flowing across the mouth 500U of bottle 560 but also, by way of "finger embouchure" the timbre of the sound can be changed depending on finger position and pressure profile and pressure distribution.
The player can block mouth 700U and also strike mouth 500U. Mouth 500U is an Alternating Current mouth because it does not sustain water flow, but merely introduces water flow in a transient (i.e. alternating pressure compressions and rar-efactions) sense.
The player can interact with these two mouths in various combinations, to achive an organlike sound with DC mouth 700U and a pianolike sound with AC mouth 500U.
In some embodiments mouth 700U may extend above the surface of the water, by way of a pipe leading from the leak or hole in duct 710 right up and out of the water.
In this way, the player can play the bottle by blocking a water jet that appears above the water surface.

In another embodiment there is a keyboard where pressing keys completes the fipple circuit or duct circuit and also strikes the bottle, for the piano organ ("pi-anorgan") or guitar violin ("guiolin") effect, which I call the AC/DC effect.
Thus a keyboard can be arranged so that hitting the keys "dings" the water in the bottles like a bell, and holding down the keys makes the water in the bottles sing.
FIG. 8 illustrates the AC/DC arrangement by way of analogy to (or even an embodiment of the invention by) a mass, such as the mass of water in the neck of a bottle, or a hanging "weight", as capacitor 800C, and spring, as inductor 800L.
Attached to the mass is shown a potentiometer which is. more typically of the to invention, rather, a Wheatstone bridge. or similar sensor 800P. The output 860 of sensor 800P is supplied to a processor 810. A graph or plot 850 of the waveform of sensor output 860 as a function of time, will show an oscillatory behaviour when capacitor 800C is struck. If the capacitor is a mass (`weight'') suspended from a, spring, then striking the weight will cause this behaviour. If the capacitor is the water in the neck of a bottle, then striking the water at the mouth of the bottle will exhibit this oscillation.
In playing the instrument of the invention, some embodiments allow for an ACDC
type of interaction in which a player can strike something, to make it ding or ring like a bell or piano, and then the player can also grab and hold the something to make it sing or sustain like a violin or organ.
The situation in Fig. 8 depicts a situation in which a player strikes the mass with an impulse to cause it to vibrate. then waits a. little while (approximately 3 milliseconds) and then grabs the mass and pulls it downwards and holds it down.
Equivalently it depicts a situation when a player hits the mouth of a bottle with the index finger, then waits 3 milliseconds, and then slaps his or her palm down on the open mouth of the bottle, sealing the mouth, and applying a. downward pressure on the water. This tirnescale is not so realistic, i.e. usually the time between striking and holding would be much more, but the plot tirnescale is simply chosen for illustrative processes.
On plot 850, the oscillations are depicted in two regimes, an AC regime 880 from when the player taps the mass, and a DC regime 881, depicting when the player presses and holds the mass.

It should also be noted that these two actions can happen together, i.e. the player can hit the mass and keep it displaced from its origin. For example, slapping the paten of the hand against an open bottle mouth will create a transient AC
signal of alternating (oscillatory) pressure waves inside the bottle and also a steady-state DC
signal resulting from an increase in the pressure inside the bottle.
The transient strike depicted in plot 850 occurs at approximately 1 millisecond and ends at a approximately 4 milliseconds. at which time the steady state strike begins to take effect from 4 milliseconds onwards. The transient oscillatory regime is what I call the DC regime. The regime where the mass is displaced away from its to central resting position, 8008, is what I call the DC regime. This is where the user has grabbed and held it away from its central position.
To sense the DC regime, processor 810 computes an average voltage over a time interval, to sense a sustained trend of the signal being away from the central position, i.e. to sense sensor output 860 being nonzero for a sustained period of time beyond the mere oscillations of the AC regime. Although grabbing and holding capactior 800C will often dampen its oscillations (i.e. introduce DC will often dampen AC), it is certainly possible for AC and DC to co-exist. For example, slapping the mouth of a bottle with the palm while simultaneously holding and pressing down tight, will cause oscillations with a DC offset. i.e. AC and DC together at the same time.
In other situations, the player might tap the side of the mouth with the index finger to make the instrument ding, like a bell, and then slide the finger over to cover the whole mouth and make the note begin to sing like a violin after the ding, as depicted in plot 850.
Another means for determining DC content is to compute a Fourier Transform in processor 810. Typically in this embodiment, a sliding window Fourier Transform is computed, and subsonic components are considered DC. In this way, even if the sensor 800P can't sense all the way down to zero Hertz, a subsonic part of sensor 800P's output 860 signal can be used by processor 810 to make the AC signal sustain longer than it would ordinarily. If the sensor can't go all the way to zero Hertz, I
still claim as an embodiment of my invention the use of subsonic frequency content to modify sonic frequency content. For example, processor 810 applies retroactive echo or reverberation to output 860 to a degree or extent controlled by a subsonic content in output 860. This retroactive echo or reverb uses a delay line or other soundstore, and reaches back into the past to loop back whenever the output 860 deviates from its central rest position 800R. The more deviance from rest position 8008, the more strongly processor 810 reaches into the past to reverberate output 860.
In other embodiments, the subsonic (i.(,. DC) components of output 860 are frequency-shifted to the same or similar frequency as the AC components. I
call this the shifterbank embodiment, because there is usually a bank of frequency shifters, one for each capacitor inductor pair (e.g. one for each bottle). For example, in the plot 850 we see that there are approximately ten cycles in the 3 millisecond AC
io Let us suppose, therefore, that this sound comes from a 330Hz "E" bottle.
In the shifterbank embodiment, processor 810 is progrannned to take whatever subsonic content occurs, and shift this up to the pitch that the capacitor and inductor are supposed to normally resonate at. In this example, processor 810 takes any sub-sonic content and frequency-shifts this up to a 330Hz note (i.e. an "E"). This can be is performed by something as simple as a 330Hz oscillator that has a voltage or strength controlled by the amount of subsonic content, to something more sophisticated such as a bank of 15 computer controlled oscillators that accept MIDI commands such as channel volume. In this case one oscillator on one channel can be controlled with channel volume change commands issued in proportion to how much subsonic (or 20 DC) sound is present. I use sound in the broad sense, i.e. to denote pressure at any frequency.
In the shifterbank embodiment it is preferable to have a temperature sensor that performs temperature compensation, so that the tuning of the oscillator matches the resonant frequency of whatever capacitor (e.g. bottle neck) and inductor (e.g.
25 bottle bulb) is being used.
Voltage deviance from the average, thus outputs a frequency-shifted sound to match the resonance of the device (e.g. bottle).
The combined AC and DC signals are amplified by amplifier 898, and output by final instrument output 899.
30 FIG. 9 illustrates a shifterbank embodiment of the invention that allows for the use of identical bottles for all of the different notes, or the use of open water regions not contained in bottles.

In the bottle embodiment 12 bottles 900 are used, whereas in the openwater embodiment 12 water regions 960 are used. A dozen hydrophones, Sensortech SQ34, denoted in the drawing as hydrophones 940. are used to pickup the sound or vibtations in water each bottle 900 or region 960. The hydrophones are each connected to a shifterbank 930 by wires 910. The shifterbank does a frequency-shift by convolution with an oscillatory wave packet recorded from a high quality Florence flask encased in concrete. In this way, ordinary Coke (TiVI) bottles, or even just slapping open water in a bathtub can be made to sound like a high quality hydraulophone.
Slapping the water at the mouths of bottles 900 or in tub 950 will produce io frequency-shifted output amplified by amplifier 998 to output signal 999.
From the foregoing description, it will thus be evident that the present invention provides a design for a musical instrument or other highly expressive input device.
As various changes can be made in the above embodiments and operating methods without departing from the spirit or scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense.
Variations or modifications to the design and construction of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications, if within the spirit of this invention, are intended to be encompassed within the scope of any claims to patent protection issuing upon this invention.

Claims (12)

1. A water pipe piano, said water pipe piano comprising one or more pipes each for being filled with water, each pipe having a proximate user-interface end, and a distal end, each distal end being connected to an elastic element, said water pipe piano also having a means for transforming vibrations in water to vibrations in air.
2. A bottle piano of claim 1, where said pipes are each a neck of a bottle, and said elastic elements are each a bulb of a bottle, and said means for transforming vibrations comprises an hydrophone for being inside each of said bottles.
3. A bottle piano of claim 1, including a number of bottles of varying size or shape, said size or shape selected such that each bottle forms a Helmholtz resonator having a frequency of a different note on a musical scale, when each bottle is completely filled with water, where each neck of each bottle is said pipe, and each bulb of each bottle is said elastic element, and said means for transforming vibrations comprises an hydrophone in each of said bottles, said hydrophones being connected to a mixer to combine electrical outputs of each of said hydrophones into a combined signal.
4. The bottle piano of claim 3, further including an amplifier having an input responsive to an output, of said combined signal, said bottle piano further in-cluding a feedback transducer arranged to excite vibrations in water in said bottles, when said bottles are filled with water.
5. The bottle piano of claim 4, said bottle piano mending a sustain pedal, said sustain pedal for altering again parameter of said amplifier.
6. A pipe piano organ including the features of claim 1, where said pipe piano organ includes an alternating current (AC) sensor for sensing alternating changes in one of (1) flow; or (2) pressure, of water in each of said (1) pipes; or (2) said elastic elements connected to said pipes, said pipe piano organ also including a direct current (DC) sensor for sensing changes in one of (1) flow; or (2) pressure, of water in each of said (1) pipes; or (2) said elastic elements connected to said pipes, said pipe piano organ further including a processor for combining an output of said AC sensor and DC sensor into an audible signal.
7. The pipe piano organ of claim 6, where said processor combines said AC and DC
signals using a delay loop to reverberate or echo said AC signal in proportion to said DC signal.
8. An infinite-sustain pipe piano organ including the features of claim 1, said infinite-sustain pipe piano organ including a sensor for sensing vibrations or flow in each of said pipes or elastic elements, said sensor for broadband sensing that extends from direct-current and subsonic sensing up into sensing audible frequencies, said sensor connected to a processor for looping, echoing, or re-verberating an alternating current component of a signal from said sensor to a degree that is proporational to a direct current or subsonic component of said signal.
9. An infinite-sustain pipe piano organ including the features of claim 1, said pipes being the necks of a plurality of Coke (TM) bottles, said instrument further including a frequency shifter connected to each of said means for transforming.
10. A coke organ, or coca-cola bottle organ, including the features of claim 1, said pipes being the necks of a plurality of Coke (TM) bottles, said instrument fur-ther including a shifterbank, an input of each shifterbank for each of a plurality of hydrophones, one inside each of said Coke bottles, said hydrophones forming part of said means for transforming.
11. A musical instrument for making music with liquids such as water, said musical instrument having a plurality of upward-facing or non-downward-facing mouths, each of said mouths being one end of a rigid pipe for supplying liquid to a player of said instrument, said instrument further including a space for elastically holding water to a second end of each of said pipes, said space comprised of (a) an elastic housing; or (b) a bulb for being filled with water, such as to form a bottle with said rigid pipe being a neck of said bottle, each of said rigid pipes and spaces chosen to resonate together at one note of a musical scale, when said rigid pipes and spaces are filled with liquid.
12. A method of playing music using Nessonators (TM), a Nessonator being defined as a hydraulic water resonator that has a mouth, a hydraulic capacitor in the form of a rigid pipe, and an hydraulic inductor in the form of an elastic element, said method comprising the steps of:

.cndot. arranging a plurality of Nessonators with their mouths facing upward, and filling each Nessonator completely with water;

.cndot. fitting each Nessonator with an acoustic transformation device that con-verts vibrations in water to vibrations in air;

.cndot. striking the mouths of the Nessonators to hit one or both of (1) water emerging from the mouths; (2) the edge of the mouth;

.cndot. keeping each Nessonator filled with water so that water displaced by said striking is replenished, to keep each of said mouths filled with water.
CA 2722916 2010-11-26 2010-11-26 Musical instrument based on water-hammer, hydraulophonic, or hydraulidiophonic percussion Abandoned CA2722916A1 (en)

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