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 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.