A proprietary, multidimensional-weighted algorithm sets an ideal target "acoustic mass" for each vent. The sophisticated 3D modeling software generates an individualized vent. This unique Acoustically Optimized Venting (AOV) value is coded into each instrument and used to optimize the fitting calculation. Occlusion can now be reduced to the lowest level possible. This exclusive, clinically proven Phonak innovation is available in the full range of custom products and styles. It is also available for BTE wearers with a SlimTip, SlimTip Soft, cShell, or xShell.