Abstract: An ultrasound beam charcterization device is provided which may be employed during manufacture of diagnostic ultrasound equipment or during use thereof in the field in order to determine the beam profile of the ultrasonic transducer. The device includes a substantially air tight enclosure or box, having therein a thin element characterized by the properties of substantially uniform acoustic scattering and a different back scatter coefficient than the surrounding filler medium. The element is preferably oriented along or parallel to the axis of radiation of the transducer, and is advantageously in the form of a synthetic resin cellular foam material having a relatively high scattering level, which may be embedded in a different foam of lower scattering level. A reticulated cellular foam and salt solution fill the remaining volume of the preferred device, thereby permitting the imaging of transducer beam profiles in a tissue equivalent material.

Abstract: An acoustic insulation curtain is composed of a number of long, relatively high mass optically transparent acoustic barrier sheets, having longitudinally extending central portions covered with panels of acoustic absorber material. The adjacent barrier sheets overlap one another. In some embodiments they are mutually spaced and also overlap portions of absorber panels of adjacent sheets. Absorber panels may be vertically discontinuous in a staggered relation from one panel to another to provide a circuitous sound absorbing air flow path from one side of the curtain to the other.

Abstract: A tone generation system is intended for use with an electronic musical instrument of the type wherein an audible tone is generated electronically in response to actuation of the instrument by a player. The invention generates digital signals capable of defining either the waveshape or the envelope or characteristic of a tone for each tone initiated by such player actuation the latter envelope being varied in accordance with the intensity of the player actuation initiating that tone. In the latter case, digital electronic circuits are utilized for developing a digital scaling signal S corresponding to the intensity of actuation of the instrument by the player, and a digital envelope signal which represents slopes and Y intercepts of portions of a composite waveform, viewed in an orthogonal coordinate system. These digital circuits arithmetically manipulate these scaling signals and envelope signals to give a composite output signal defining the envelope.This application is a continuation of application Ser.

Abstract: An ultrasound phantom is provided which has ultrasound wave velocities, attenuation coefficients and scattering coefficients which closely mimic those of human tissue and which permits diagnostic ultrasound equipment to be accurately tested and calibrated on a continuing day-to-day basis. The phantom preferably includes a substantially air-tight enclosure or box, having therein a quantity of reticulated synthetic resin foam material and a salt water solution. The ultrasonic characteristics of the phantom are completely uniform, stable and reproduceable, can be varied at will by using different foam materials and/or liquids, and the phantom can be stored and used at room temperature without degradation thereof. Localized zones having different ultrasonic qualities for mimicking various normal and pathological tissues can also be provided by hollowed, cut-out regions within the foam material, with different inserts located within certain of the hollowed regions.

Abstract: An adjustable light and air-admitting thermal and acoustic barrier has a plurality of sound-attenuating blades pivotally mounted in a frame in a mutually spaced, parallel relationship. When the barrier is mounted at an open window, the blades may be adjusted to various open positions to allow desired amounts of outside light and air into a room, but cooperate in such open positions to form an effective sound trap for annoying outside sounds. Each of the blades functions as both a sound absorber and a sound transmission barrier, and comprises an elongated, relatively thin core of solid, sound-reflective material having longitudinally extending edge and intermediate flanges which define cavities on opposite sides of the core. Secured within the cavities by the flanges are strips of sound-absorbing insulating material, the core and insulating material being laterally enfolded by a cover secured to the flanges.