Hydraulophone
A water-based musical instrument played by blocking water jets.
A hydraulophone is a musical instrument that produces sound through hydraulic action, typically played by touching water (or another fluid) directly. The term was introduced by Steve Mann in 2005, and he patented the design in 2011. In most cases, the same fluid that touches the player’s fingers also generates the sound. The instrument has also served as a sensory exploration tool for people with low vision.
The instrument can be defined by its playing interface: a player blocks water flowing from a specific hole to sound a particular note. Sound is created using water-flow mechanisms, such as water jets striking perforated spinning disks, shafts, or valves—similar to a siren disk. A single disk or shaft may have rings or passages with varying numbers of holes for different notes. Some hydraulophones include reeds (one or more per finger hole), while others are reedless and use fipple mechanisms, meaning no moving parts wear out. Blocking a finger hole redirects water to one or more sound-producing mechanisms, or changes in flow or pressure affect a separate sounding mechanism tied to that hole. In some versions, a hydrophone electrically amplifies the sound, and further signal processing may be applied. Other embodiments use acoustic or optical pickups. Electric amplification allows effects (like those used with an electric guitar) and makes the hydraulophone a hyper-acoustic instrument, where computation alters the water’s acoustic sound into another instrument’s timbre.
A pump—hand-operated, wind-powered, water-powered, or electric—forces water into the hydraulophone. Unlike woodwind instruments, which have one mouthpiece at the entrance, hydraulophones have a mouthpiece at every exit port. While a ducted flute has one fipple mechanism for the player’s mouth and several finger holes sharing it, a hydraulophone gives each finger hole its own mouth. A typical park hydraulophone has 12 mouths; a concert version has 45. The player controls embouchure through the instrument’s mouths, not their own mouth, so they can sing while playing. This also enables polyphonic embouchure: each note’s sound can be shaped by the finger’s position and shape inside the mouth—for example, fingering the center of a water jet produces a different sound than fingering near the edge.
The hydraulophone resembles a woodwind instrument but uses an incompressible or less compressibl
- Inventor
- Steve Mann
- Year described
- 2005
- Year patented
- 2011
- Category
- Musical instrument
- Sound production
- Hydraulic (water-flow sound-producing mechanisms)
- Common types
- 12-jet diatonic, 45-jet chromatic/concert
Lore & Background
The hydraulophone uses water-flow sound-producing mechanisms. Its user interface involves blocking water jets to produce sound. Sound is produced by water jets striking perforated spinning disks, shafts, or valves, creating a pulsating water flow similar to a siren disk. Some hydraulophones have reeds; others are reedless with fipple mechanisms. Blocking flow through a finger hole directs water to sound-production mechanisms, and the resulting changes in flow or pressure affect a separate sounding mechanism associated with each finger hole. Blocking water from a given hole produces a given note, which may be electrically amplified by a hydrophone.
Unlike woodwind instruments with one mouthpiece at the entrance, hydraulophones have mouthpieces at every exit port. A typical park hydraulophone has 12 mouths; a concert hydraulophone has 45 mouths. Embouchure is controlled by the instrument's mouth, not the player's, allowing the player to sing along. The instrument provides polyphonic embouchure, where each note can be dynamically shaped by the position of the finger inserted into each mouth.
The hydraulophone is similar to a woodwind instrument but uses incompressible fluid rather than air. It is sometimes called a 'woodwater' instrument. Many hydraulophones include a separate water-filled pipe for each note, similar to a pipe organ but with water. On a concert hydraulophone, finger holes are arranged like piano keys. The response differs from piano (velocity) and organ (displacement); hydraulophones respond to time-integral of displacement, displacement, velocity, and to some degree jerk and jounce.
Reader's Guide
The hydraulophone represents a novel intersection of music, hydraulics, and accessibility. Its significance lies in its unique interface—using water jets as both the sound source and the playing mechanism—which offers a tactile, multi-sensory experience. The instrument's use as a sensory exploration device for low-vision individuals highlights its potential beyond traditional music performance. The hydraulophone's design, with separate mouthpieces for each finger hole, allows for polyphonic embouchure and simultaneous singing, expanding expressive possibilities. Its installation in public spaces, such as the 45-jet concert hydraulophone at the Ontario Science Centre and themed installations like the Aquatune at Legoland, demonstrates its role as both an artistic and educational tool. The instrument's legacy includes its contribution to the field of hyper-acoustic instruments, where computation alters the acoustic sound of water into other instruments. The hydraulophone also challenges conventional instrument classification, bridging woodwind, organ, and piano concepts while using water as the primary medium.
Did You Know?
- The hydraulophone was described and named by Steve Mann in 2005 and patented in 2011.
- It has been used as a sensory exploration device for low-vision individuals.
- A typical park hydraulophone has 12 mouths, while a concert hydraulophone has 45 mouths.
- Finger holes on some hydraulophones are encoded in Braille to aid players when water spray obscures vision.
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