Design Salients include:

• The foundation of the anechoic chamber is constructed within a reinforced concrete retaining wall containing six tons of sand, supporting a sub-floor system designed to absorb and cancel ultra-low frequency vibrations.
• The innermost floor on which the inner chamber is built floats on 40 high-tension steel springs.
• Throughout the entire structure, no two materials of the same kind come directly in contact. Because each particular material vibrates at a specific rate and transfers vibrations in certain frequencies, VFI’s construction is designed to break up vibrations and prevent their transfer.
• All surfaces are constructed at oblique angles; no right angles exist inside the chamber. This ensures the reverb-free, noiseless environment crucial for TTS applications.
• Eight feet of high-density, acoustic-grade fiberglass, plus nine inches of acoustic-grade Celetex^â are housed in between the outer and inner walls of the structure.
• Two feet of anechoic wedge Sonex^â are affixed to every wall and ceiling of the chamber.
• Three four-inch air spaces separate the walls and sound insulating materials. Each wall is faced with three inches of sheetrock for a total 1 foot of sheetrock.
• Sealing the VFI chamber’s joints and contact points required over five hundred pounds of acoustic caulking.
• To silence heating, ventilation and air conditioning (HVAC), the VFI chamber incorporates a five-ton unit that delivers conditioned air through four hundred feet of ductwork that gradually increases in size and feeds into a primary baffling system (8 ft x 12 ft x 3 ft), which in turn feeds conditioned air through one hundred feet of ductwork, into another baffle, and finally into the chamber. Air returns are similarly constructed. There is absolutely no detectable noise in the chamber, even when the most sensitive microphone is held up directly to the vents.
• To enter the chamber, one must go through two soundproof metal doors weighing eight hundred pounds each.

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