Sound suppression of engine noise

A method and apparatus for suppressing sound generated by engines or other noise sources, by utilizing at least two acoustical encasements separated by an air channel with air being drawn through the air channel to provide intake air to the noise source. Sound leaks through the intake vent are attenuated by the air channel. Entrainment devices or an auxillary fan may be used to compensate for loss of air intake due to pressure losses through the air channel. Also, the use of entrainment allows for a smaller exhaust vent which reduces the opening ratio in the encasement, thus reducing sound leaks through the exhaust vent. Additionally, sound absorbing or attenuating materials are placed inside the intake air channel, thus suppressing the sound emanating from the noise source. Also, the exhaust vent is lined with proper absorbing materials to further reduce sound coming from the noise source. Furthermore, the inside encasement is substantially isolated from the outside encasement.