Lencore’s Model LE035M6-RCVC is typically used HVAC duct when eavesdropping is an issue. This unit is installed within the HVAC duct to achieve speech privacy. The unit consist of an individual self-contained noise generator, audio amplifier, and loudspeaker in a damped metal enclosure, powered by 16/18 volts AC and are capable of driving two secondary models. Each main unit is solid state and consists of a CMOS/ MSI digital random sequence noise generator, electronic amplifier and filter for active spectrum shaping, and is equipped with a 10-step volume control plus an additional continuous volume control. Range of sound level: 56-86 dBA (measured at 1.5 feet from speaker). Additionally contained is a continuous and completely separate volume control for music/paging. The masking system can be uniquely adjusted to suit a variety of standard and non-standard ceiling conditions by making adjustments to the amplitude and spectra shapes. This adjustment can be made in increments of +/ - 1/2 dB. In addition, the system has the adjustment capability to provide the most unobtrusive sound while obtaining the maximum speech privacy that meets ASTM E-1130 standards for speech privacy and sound uniformity. The spectrum shape adjustment ranges from 1dB at 125 Hz to 20 dB at 8,000 Hz (typical
