Abstract: A detachable (portable) electrical pickup for musical instruments, such as basses, that includes a clamp to secure the pickup to the bridge of an instrument, a piezo crystal sensor, an integral audio jack, and a volume control. Also included are musician removable and interchangeable weights that are used to alter the response characteristics and to control any deleterious feedback.

Abstract: Provided is a transducer that can be attached to a desired position and removed therefrom and that does not damage musical instruments. A first magnet member and a second magnet member are mutually attracted toward one another by magnetic force across the top board of a ukulele. Thus, a receiver unit including a piezoelectric element, which is supported by the first magnet member, can be positioned at a desired position. Because the receiver unit is kept in position only by the mutually attracting magnetic forces, the receiver unit can be moved to any desired position even after once being positioned on the top surface of the ukulele.

Abstract: A percussion detecting apparatus capable of enhancing an effect of disturbance interception by intercepting a micro-vibration conveyed from a support frame. A pad member has a pad having a back-side surface to which a base is fixed, and a percussion sensor is disposed on a back-side surface of the base. The pad member is supported by a frame via fixing members integral with the pad member and intervening members made of silicon rubber. Vertical protrusions having different protrusion heights are formed on an upper surface of a flange of each intervening member, and horizontal protrusions are formed on an inner peripheral surface of a through-hole of each intervening member. When the pad member in an unstruck state, each fixing member is in contact with a corresponding one of the intervening members only at the vertical and horizontal protrusions of the intervening member.

Abstract: A percussion instrument striking detection device is configured to minimize time lag from striking the head until detection of head vibrations and for reliable detection of the vibrations in conformance with the striking force without regard to the head condition. A striking member has a vibration sensor. Therefore, the distance from the striking location on the head to the vibration sensor can be short, to minimize time lag. In addition, the effect of the tension or the material of the head on the vibrations detected by the vibration sensor can be minimized and vibrations in conformance with the striking force can be reliably detected.

Abstract: The present invention includes an electronic cymbal assembly including a hi-hat clutch for mounting a hi-hat to a hi-hat stand post; a top cymbal; a self dampening trigger system attached to the underside of the top cymbal; a bottom cymbal; an input jack box mounted to the underside of the bottom cymbal; and a hi-hat cymbal mounting post. The cymbal assembly may be mounted using a magnetic ring configuration or a threaded pole configuration.

Abstract: An improved transducer structure for musical instruments, principally for stringed instruments, permitting the production of an electrical analog signal which faithfully reproduces sound waves conducted to a sensor from the surface of the instrument through the attachment surface of the transducer and air borne sound waves incident on the elevated structure of the transducer, with nominal distortion. The sensors which are effective using this transducer technology include piezo-electrical sensors, magnetic sensors and capacitive pickups are made part of a symmetric resonant structure none of whose sides are parallel.

Abstract: A piezo electric element generates a vibrating voltage in response to a striking force on a pad. The piezo electric element is connected across a series connection of a linear resistor and a nonlinear resistance network. The voltage appearing across the nonlinear resistance network is taken as an output voltage. The nonlinear resistance network is comprised of a parallel connection of a first and a second resistance circuitry. The first resistance circuitry is a series connection of a resister and two diodes connected in parallel in an opposite polarity to each other. The second resistance circuitry is a series connection of another resister and two Zener diodes connected in series in an opposite polarity to each other.

Abstract: Embodiments are directed to a novel technique used to create electronic apparel that is powered by batteries and generates light, or sound in reaction to various sensors on the garment. The wearer through the use of various options or effects can further modify the output through the use of various options or effects. The electronic apparel includes an image of an instrument and a keypad that allows for user control of sounds generated by electronic circuits incorporated in the garment. Sound generation circuitry and speakers are coupled to the keypad in an electronic assembly that is detachably coupled to the garment in such a way as to allow regular washing of the garment without any damage to the electronic devices.

Abstract: A tuning device includes a weighted housing which reduces transfer of vibrations of all strings of a stringed musical instrument to a body of the stringed musical instrument, and tuning circuitry which simultaneously detects a pitch of each vibrating string. A method of tuning a stringed musical instrument includes attaching an electronic tuning device to a bridge of the stringed musical instrument, activating the electronic tuning device, causing a plurality of strings of the stringed musical instrument to vibrate simultaneously, and individually adjusting a pitch of each of the simultaneously vibrating strings in accordance with a pitch indication for each of the strings produced by the electronic tuning device.

Abstract: A transducer includes a piezoelectric element attached to a stringed musical instrument with an adhesive layer, and at least one intermediate layer provided in a thickness-wise middle portion of the adhesive layer and made of a material different from a material of the adhesive layer. The transducer has a mounting surface attached to face a back surface of a top of a body of the stringed musical instrument, and the mounting surface is disposed in an area, in the top, including an area right under an installation area of a bridge which is provided on a front surface of the top and supports a saddle supporting one-end sides of strings.

Abstract: A piezo electric element generates a vibrating voltage in response to a striking force on a pad. The piezo electric element is connected across a series connection of a linear resistor and a nonlinear resistance network. The voltage appearing across the nonlinear resistance network is taken as an output voltage. The nonlinear resistance network is comprised of a parallel connection of a first and a second resistance circuitry. The first resistance circuitry is a series connection of a resister and two diodes connected in parallel in an opposite polarity to each other. The second resistance circuitry is a series connection of another resister and two Zener diodes connected in series in an opposite polarity to each other.

Abstract: One embodiment of the Touch sensitive impact controlled signal transfer device invention whereas the invention is used as a musical glove device that sends electrical signals to a sound module when areas of the glove containing piezoelectric discs are tapped or otherwise impacted on a surface and where the force applied by impact to the piezoelectric disc or discs is interpreted by the sound module and said module produces a sound at a volume level directly related to the force of impact on the piezoelectric discs and where multiple piezoelectric disks are located in each glove allowing a plurality of sounds by tapping different areas of the glove, such as the palm, thumb and fingers.

Abstract: An improved transducer structure for musical instruments, principally for stringed instruments, permitting the production of an electrical analog signal which faithfully reproduces sound waves conducted to a sensor from the surface of the instrument through the attachment surface of the transducer and air borne sound waves incident on the elevated structure of the transducer, with nominal distortion. The sensors which are effective using this transducer technology include piezo-electrical sensors, magnetic sensors and capacitive pickups are made part of a symmetric resonant structure none of whose sides are parallel.

Abstract: Disclosed is a stringed instrument with embedded DSP modeling capabilities to model an acoustic stringed instrument. The stringed instrument has a body and a plurality of strings and each of the plurality of strings is respectively coupled to a pickup to detect a vibration signal for each string. An A/D converter converts the detected vibration signal of a string into a digital string vibration signal. A DSP is located within the body of the stringed instrument to process the digital string vibration signal and to implement an acoustic modeling system to process the digital string vibration signal in order to emulate a corresponding string tone of one of a plurality of selectable acoustic stringed instruments. Acoustic modeling includes acoustic string and body modeling, microphone placement modeling, and pick-sound modeling. The emulated acoustic digital tone signal is then converted to analog form for output to an amplification device.

Abstract: An electric cello is equipped with a pickup unit under a bridge, and strings are stretched to press the bridge; the pickup unit has a bridge tray where the bridge stands and a piezoelectric transducer provided beneath the bridge tray, and the bridge tray is bolted at a side portion under the thick string to the instrument body; however, the other side portion under the thin string is made freely vibrate; while a player is bowing on the strings, the vibrating strings give rise to rolling of the bridge, and the leg portions of bridge are alternately pressed on the side portion and the other side portion; only the vibration of the other side portion give rise to deformation of piezoelectric converter so that the piezoelectric converter is free from interference of the bolted side portion.

Abstract: South Asia's unique musical instruments and raag systems have provided many rich treasures to Western music. This invention melds Western-music technologies with the innovations, timbre, playing techniques, and performance environments of South Asian musical instruments and traditions. Sitars, Dilrubas, and Esraj may be provided with multi-channel signal processing and pitch change for individual strings, additional playing strings, keyboards, strumpads, percussion interfaces, controls for timbre and stage environment control, synthesizer interfaces, pickups for brass strings, resonant and twang processors, and spatial sound distribution. Bows may include sensors measuring the bow's physical activity or direct finger manipulation. Tabla and baya may be replaced with touch pads capable of recognizing relevant hand contact modalities and positions. Touch pads may be comprised of pressure sensor arrays that recognize traditional bols and permit other generalizations and deeper levels of sonic control.

Abstract: An audio effects control for and method of controlling the application of special audio effects applied to an audio signal, comprises a sensor configured to sense movement associated with the generation of the audio signal, wherein the sensor produces a control signal in response to detecting the movement, and the control signal is transmitted to an audio effects unit to control application of an audio effect on an audio signal.

Abstract: A transducer for converting mechanical vibrations to an electrical signal and/or for converting an electrical signal to mechanical vibration. Damping liquid damps the relative vibration of transducer components. The damping liquid can be selected to optimize the sound quality of acoustic vibrations at the point of transduction. Also, a transducer with components that rotate relative to each other. For example, a permanent magnet component may simultaneous vibrate rotationally and linearly with respect to an electric signal carrying coil. The characteristics of the rotational vibration may be adjusted to optimize sound quality of acoustic vibrations at the point of transduction.

Abstract: An apparatus for detecting the displacement of a movable member of an electronic musical instrument. The apparatus has superior mechanical durability compared to displacement sensors of the past and can withstand long-term use. The apparatus includes a sensor that provides a detectable electrical characteristic having a value and a spring that, when compressed upon displacement of the movable member acts with the sensor, causing the value of the electrical characteristic to change. The value of the electrical characteristic represents the amount of displacement of the movable member and is used by a controller of the electronic musical instrument.

Abstract: An electronic percussion instrument that detects vibrations due to a hit and outputs a corresponding signal where the head of the instrument is held in place independent of a rim part. The independence stops vibrations originating from a hit of the rim from traveling to the head and interfering with the proper signal detection of hits to the head part.

Abstract: An electronic hi-hat cymbal comprises a hi-hat having a strike detector, a pedal unit having a stepped degree detector, a waveform data memory for storing a plurality of electronic hi-hat sound waveform data, corresponding to respective stepped degrees, in a plurality of stages, a CPU, a musical tone generating controller, and so forth. The CPU causes the musical tone generating controller to read out electronic hi-hat sound waveform data corresponding to a stepped degree in the pedal unit from the waveform data memory when a strike to the hi-hat is detected to thereby generate a musical tone signal before outputting, and when a change occurs to the stepped degree during a musical tone being produced thereafter, to read out electronic hi-hat sound waveform data corresponding to a new stepped degree halfway through to thereby generate a musical tone signal to be outputted, which is continued while the musical tone is being produced.

Abstract: A method and apparatus provides metronomes capable of wireless synchronization with other similar metronomes. A metronome includes a tactile device capable of conveying the tempo and beat to a user without the use of sound. In one example, one of the metronomes is used as a lead unit (for example, controlled by a band leader or conductor) and transmits control signals to the other metronomes. This allows multiple musicians in an orchestra, or similar music ensemble, to each have a metronome that is synchronized with other metronomes and shares a common tempo and beat.

Abstract: An electronic drum system includes an electronic drum having a shell, a drum head stretched across an opening of the shell, a vibration sensor converting vibrations of the drum head to an electric signal and a damper held in contact with the reverse surface of the drum head; when a drummer strikes the drum head with a stick, the drum head is shaken, and vibrations follow; the damper is held in contact with a certain area on the reverse surface, and the shake and vibrations are propagated from another area free from the damper to the vibration sensor; the shake is surely propagated to the vibration sensor, and the vibrations are rapidly decayed; for this reason, the vibration sensor exactly discriminates the shake from the peaks of the vibrations, thereby preventing an electronic sound generator from unintentionally repeated electronic beats.

Abstract: A stringed musical instrument device that functions as a peripheral for a computer or computing device, whereby electronic transducers placed inside and/or outside the instrument convert the vibrations of the strings and/or the instrument body from an analog electrical signals to digital signals. The digital signals are then transmitted via Class Compliant USB and/or FireWire-IEEE 1394 and/or IEEE 802.11 wireless and/or Bluetooth® wireless protocols to any computer or computing device that accepts data via those protocols. This device requires no external power, amplification, analog-to-digital conversion, software or hardware. This device is an improvement over the prior art in that it accurately and immediately represents on a computer or computing device the signals that are being sent from the instrument and reduces the number of devices needed to accomplish the task of sending digital signals to a computer or computing device.

Abstract: A mobile wireless communication terminal includes a wireless communication module and a controller. The wireless communication module is configured to communicate with other communication terminals over a wireless interface. The controller is configured to establish a connection with a participant wireless communication terminal via the wireless communication module, to maintain a play list representing song files to be played, to receive a participant song identification from the participant wireless communication terminal, wherein the participant song identification corresponds to a participant song file stored on the participant wireless communication terminal, to add the participant song identification to the play list, and to thereafter execute playback of the song files represented by the play list, including retrieving the participant song file from the participant wireless communication terminal for playback.

Abstract: A key driving apparatus for driving a key may include, but is not limited to, a first elastically deformable unit. The first elastically deformable unit is configured to receive a first control voltage. The first elastically deformable unit is configured to show elastic deformations of stretch and shrinkage based on the level of the first control voltage. The first elastically deformable unit is configured to allow the key to be driven by the elastic deformations of stretch and shrinkage of the first elastically deformable unit.

Abstract: An electrified musical instrument having a pickup wire (30), multiple strings (6), and a frame, typically comprising a head (2), diagonal arm (24), front column (16), and rear column (18), arranged in such a way as to provide an electrical signal from vibrations in the strings.

Abstract: A musical instrument is provided. The instrument is light weight and portable. The instrument includes electrical pickup capabilities but also has the feel of an acoustic instrument. The instrument can be folded to an arrangement that is easy for transport. The folding instrument has maximum similarity to an acoustic cello, including the feel and size when unfolded. The instrument includes a floating soundboard to provide maximum acoustic feel. The instrument further includes an acoustic pickup.

Abstract: A method of making musical sounds from a musical instrument may include amplifying musical sounds from vibrations of a vibrating element when a musical instrument is played, sensing forces between the musical instrument and the vibrating element and altering the forces applied to the vibrating element in response to the sensed forces to emulate musical sounds produced by a musical instrument having different musical characteristics, for example, to emulate an acoustic guitar. Piezoelectric material or magnetic material may be used to apply forces along one or more than one axis of vibration and may be controlled by a replaceable element and/or in response to user adjustments. The applied forces may be adjusted to control relative phase between the sensed and applied forces to avoid unwanted musical effects, such as unwanted sustained oscillation, in response to a fundamental period of the vibrations or random number generation to change the vibration waveform.

Abstract: A game apparatus includes an operating switch and a microphone. A player operates a player object through intuition by the operating switch or inputting a sound. The number of zero crossings contained in waveform of a sound input through the microphone is detected, and also individual interval times between the zero crossings are detected. Then, it is determined whether or not the distribution of the interval times, i.e. the frequency distribution matches the distribution of interval times (frequency distribution) related to a breath sound stored in advance. If there is a match between the two, the input sound is recognized as a breath sound, and a game process based on the breath (wind) is carried out. For example, a game screen depicting the breath or wind is displayed on an LCD.

Abstract: A device (10) used by a drummer to produce low frequency signals in response to the playing of a bass drum (D). Low frequency signals from the device are first amplified and then sent to a subwoofer near the drummer, or tactile transducer connected to the drummer's chair (C). This results in a powerful shaking effect each time the drum is struck. The device is used in a stand alone audio circuit and does not require connection into a band's complete audio system. This is important because it allows the drummer to feel a powerful shaking effect each time the drum is struck when practicing or while playing in situations where an audio system is limited or non-existent.

Abstract: An apparatus for detecting the displacement of a movable member of an electronic musical instrument. The apparatus has superior mechanical durability compared to displacement sensors of the past and can withstand long-term use. The apparatus includes a sensor that provides a detectable electrical characteristic having a value and a spring that, when compressed upon displacement of the movable member acts with the sensor, causing the value of the electrical characteristic to change. The value of the electrical characteristic represents the amount of displacement of the movable member and is used by a controller of the electronic musical instrument.

Abstract: A method and system for producing synthesizer and MIDI control data and for reconstructing and reproducing a signal from data collected by sensors coupled to a string instrument comprising a plurality of sensors coupled to the string instrument and a control unit that is associated with the plurality of sensors. The sensors are adapted to collect temporal and spatial data referring to performer's actions and to the sound generation process of the string instrument, specifically as to string deflection along time, while the control unit is adapted to process the data and generate a signal corresponding to the sound characteristics of the performer's playing and actions on the string instrument.

Abstract: Methods and apparatus for manipulating physical objects to produce sounds that are correlated with the feel of the objects being manipulated. Example devices called the PebbleBox, CrumbleBag and ScrubberGlove each use the manipulation of physical objects of arbitrary material as the basis for interacting with granular sound synthesis models. The sounds made by the objects as they are manipulated produce sound signal events that are detected and used to trigger and control the reproduction of stored sound samples in real time.

Abstract: A pickup device (11) sandwiched between strings (3) and a top (4) of a body in a plucked string instrument comprises: a saddle (16) transmitting vibrations of the strings (3) to the body; and a bridge (25) fixedly attached on the top (4) of the body to support the saddle (16). Piezoelectric films (17, 18) being piezoelectric elements are pasted on areas of a front surface of the bridge (25) excluding a portion in which the saddle (16) is fitted. The vibrations of the strings (3) cause the pickup device (11) to also vibrate together with the top (4) of the body, and the portions of the bridge (25) on which the piezoelectric films (17, 18) are pasted make the largest bending deformations. The piezoelectric films (17, 18) are also free to make bending deformations to efficiently output electrical signals by a piezoelectric effect for musical sound in all pitch ranges.

Abstract: A sound determination unit previously divides sound into a low sound range for first sound, a middle sound range for second sound, and a high sound range for third sound by its frequency band. When sound information detected by the microphone is inputted to the sound determination unit, the sound determination unit determines whether the frequency band of that sound information is in the predetermined low sound range or not. When it is in the low sound range, a signal to operate a first vibrator is generated from a first controller. When it is in the middle sound range, a signal to operate a second vibrator is generated from a second controller. When it is in the high sound range, a signal to operate a third vibrator is generated from a third controller.

Abstract: An electric contrabass has a bridge structure on a body in which an inner space is defined, and the body is further formed with a slit under the bridge structure so that the lid of the body vibrates like a cantilever; a vibration sensor is provided inside the body, and has a vibration sensitive surface held in contact with the lower surface of the lid; while a player is bowing the strings, the vibrating strings excite the lid through the bridge structure, and the vibrations of the lid is converted to an electric signal through the vibration sensor; since the distance from the vibrating strings and the single vibration sensor is approximately equal, the single vibration sensor produces the electric signal without undesirable imbalance and interference.

Abstract: A ring-shaped percussion transducer for converting a striking impact into a representative electrical pulse triggering signal is suitable for mounting on the center axis of a percussion instrument. In a preferred embodiment, the transducer is formed of a piezo electric material of ring shape; protected on the top and bottom by thinner ring shaped washers; enclosed in a protective coating and mounted along the center axis of a percussion device which when struck transmits vibrations to the percussion transducer. The percussion transducer is connected to conventional downstream electronics so as to produce a sound responsive to the striking impact.

Abstract: An electro-acoustically amplified drum mixer or sound level adjuster for amplifying a hollow drum shell having at least one open end, a drumhead spaced from the open end of the said drum shell and supported thereon. One or more microphones are supported on, and positioned within said drum shell and adapted for connection to an external amplifier and speaker. A second or additional microphones may be included with the internal mounting or may be adapted for mounting outside the drum housing.

Abstract: An electronic tone generation system including a plurality of separate, portable, handheld transmitters, or batons, that are provided as “instruments” to one or more players. Each baton can be activated to send a signal, preferably a wireless signal, to a single receiver which produces an output signal fed to a tone generator, preferably a MIDI tone generator, which produces audible sounds via an amplifier and speakers. For example, the batons can correspond to different musical notes as played by a selected musical instrument and the batons can be played in concert to produce a musical or other audible presentation. Alternatively, selected batons can be designated to play in one voice, while others batons are set to play other voices.

Abstract: An electronic percussion instrument includes input means, correction information storage means, and musical tone generation means. The input means allows for vibration information, which expresses a vibration of an operator, position information, which expresses a position of the operator, and standard position information, which indicates a standard position of the operator, to be input. The correction information storage means allows for correction information to be stored that is based on the position information that has been input in the input means that corresponds to the standard position information that has been input in the input means. The musical tone generation means allows for the generation of a musical tone in conformance with the position information that has been input in the input means that corresponds to the vibration information that has been input and the correction information that has been stored in the correction information storage means.

Abstract: An electric acoustic stringed musical instrument is a combination between an acoustic stringed musical instrument and an electric system; while a player is bowing on the strings, the strings not only laterally vibrate but also are repeatedly elongated and shrunk so as to give rise to rolling motion and pitching motion of the bridge; a strain sensor sensitive to the lateral component force of the vibrations and another strain sensor sensitive to the longitudinal component force are provided in and on the bridge for producing electric signals; since the timbre of tones is varied dependent on the ratio between the lateral component force and the longitudinal component force, the player can express his artistic expression in the electric tones by strongly or gently pressing the bow onto the strings.

Abstract: A sound augmentation system for a drum comprises a wave generator for producing an electrical signal corresponding to a predetermined sound, an amplifier for amplifying the electrical signal to produce an amplified electrical signal, and a driver for translating the amplified electrical signal to a plurality of sound waves. The wave generator, amplifier and driver are mounted to a support structure configured to fit within a body of the drum. In operation, a strike of the head of the drum produces amplified sound waves that emanate from the body of the drum. Various embodiments of the sound augmentation system and associated method are provided.

Abstract: A sound pickup switching system for an electric string instrument which has at least two pickup coils and a multi-position selector switch, includes a switch matrix with a plurality of switches in it connected to the pickup coils. The switch matrix electrically interconnects the pickup coils in predetermined combinations of series, parallel, in-phase, or out-of-phase arrangements. A relay driver is coupled to the switch matrix to operate the switches under control of outputs from a table memory coupled with the relay driver. User input controls are coupled with the table memory for entering and storing groups of user selected switch combinations in the table memory; and connections are made between the selector switch on the string instrument and the table memory for enabling the table memory to cause the relay driver to operate predetermined combinations of switches in the switch matrix corresponding to different positions of the selector switch on the electric string instrument.

Abstract: A tactile metronome for use by a musician generally includes a signal generator for producing an electrical signal according to a desired timing scheme and a tactile transducer in electrical communication with the signal generator. The tactile transducer, which may take the form of a piezoelectric device, a buzzer, electrodes or any substantial equivalent, is adapted to impart a tactile sensation to the musician in response to the generated electrical signal. A strap, which may be formed from an elastic material or a soft cloth material with hook and loop fasteners, is provided to secure the tactile transducer in place on the musician's body.

Abstract: This invention relates to a pickup and base structure of a drum head, in particular, a pickup applied to a mesh head or a hard drum head having the base thereof in a hollow L-shape, thereby allowing a vertical space to position a terminal base of a signal line and a horizontal portion in a L shape to form a recess inwards. A shock isolator is integrally formed with the pickup in one piece by clamping said pickup from both above and below, in addition, another shock isolator is fastened on the vertical side on the exterior of the base. The structure is fixed on the underside of the drum head and the shock isolator that is fastened on the vertical side on the exterior of the base is against on a position corresponding to the drum body, so as to form the pickup and base structure of a drum head that is easily to be installed.

Abstract: A sound pickup device, which is arranged in proximity to a percussion instrument (e.g., a bass drum), comprises a diaphragm stretched under tension over an opening of a shell having a cylindrical shape, and an electroacoustic transducer arranged inside of the shell. The electroacoustic transducer comprises a magnetic transducer or a speaker unit. Herein, the percussion instrument is played to produce the low-pitch sound, which is transmitted to the diaphragm to vibrate so that the electroacoustic transducer is activated to convert the low-pitch sound into an electric signal, based on which the low-pitch sound is reproduced by a sound system with a high fidelity to the original sound.

Abstract: A soundhole accessible musical instrument control platform mounted inside the body of a musical instrument requires no physical alterations to the instrument, allowing the user convenient and ergonomic access to the control platform through the soundhole while using the musical instrument. The control platform includes a circuit platform, mounted inside the instrument with adhesives, separably attached to a mounting bracket. Control detents and markings are easy to feel and to read and thus provide feedback for control position and the relative degree of effect. The controls are surrounded by a cosmetic bezel that hides the actual mounting mechanism and circuitry. Any combination of controls, circuitry, and sensors may be used. Power is either provided onboard or offboard. An output connector may be integrated into the circuit platform or via an endpin jack.

Abstract: A transmitter for recording of an electric signal from an acoustic drum having a vibration-sensitive device for attachment to the drumhead and for acquisition of undulations which has one of the following profiles: sector shape, sector shape with a tip turned toward the center of the drumhead, sector shape with concave sides and with a tip turned toward the center of the drumhead, circular shape with wart-like projection turned toward the center, elliptical shape with wart-like projection, which is arranged at radius of curvature one side large and is directed towards the center of the drumhead, or rectangular shape with wart-like projection which is arranged on a lateral edge of the rectangle and is directed towards the center of the drumhead.

Abstract: Transducer for converting mechanical stress into electric signals, which transducer is composed of at least one electromechanical sheet (107,108) and is capable of converting mechanical stress into electric signals and in which transducer at least one of the electrodes required by the electromechanical sheet is disposed on the surface of one or more thin and flexible dielectric materials, said electrodes (109) forming electrically conductive surfaces of the transducer for connecting the transducer to a signal processing device, said electromechanical sheets being permanently charged cellular electret film and which transducer is constructed of a unitary, thin and flexible layered laminate structure.