[ Protective helmets; sound protective helmets; ] amplifiers; electronic noise reducing apparatus; electronic apparatus to actively reduce sound and vibration levels, namely, active noise reducing headsets, active noise reducing headsets for communication, active noise reduction cassettes for use with heating and ventilation systems, active exhaust quieting system comprised of speakers, microphones, controllers, electronic reactive indicator panels, active vibration control systems comprised of actuators, vibration sensors, controllers, active noise quieting systems for quieting areas in buildings, vehicles, open spaces and for use in quieting electronic communication systems; earphones, telephone apparatus and receivers, microphones; loudspeakers, cabinets for loudspeakers; acoustic conduits; acoustic couplers; acoustic diaphragms; transmitters of electronic signals; [ apparatus for recording, ] transmission or reproduction of sound; electronic sound locating instruments; printed circuits; [ computers, ] calculators, calculating machines; electrical and electronic measuring apparatus, namely, electronic apparatus to measure sound and vibration, namely, microphones and microphones arrays, accelerometers and accelerometer arrays; electrical and electronic sound and vibration measuring instruments and apparatus; [ wavemeters; radios; ] audio receivers

Development and design of computer software for scientific research; conducting of technical feasibility studies; research on acoustics; appraisal services, namely, measurement evaluation services in the field of passive and active noise reduction, active vibration control, and characterization of sound and vibration; surveying; rental of computers, measuring apparatus and computer software