Whispering in the private domain plays a clearly positive role... it can serve to mediate tenderness [ingroup signal] or even support the bond between males. This privacy is facilitated by an amount of acoustical perfume. They argued that the best way to get rid of noise in speech systems should not be to reduce the noise power as much as possible [Parakalo], but to make the noise inaudible or to minimize its subjective loudness. In many situations noise-control problems can be solver by drowning out unwanted noises by electronically created background noise. Noise from ventilating systems, from a uniform flow of traffic, or from general office activities contributes to artificial masking noise [Teals] and provide a reasonable amount of privacy.