181 / | HD | ACOUSTICS |
175 | DF | SOUND-MODIFYING MEANS {12} |
198 | DF | .~ Housing or enclosure (e.g., sound confining and absorbing) {2} |
200 | .~.~ Machine type enclosure {5} | |
201 | DF | .~.~.~> Offfice type devices (e.g., typewriters, teleprinters, etc.) |
202 | DF | .~.~.~> Electical type devices (e.g., transformers, motors, etc.) |
203 | DF | .~.~.~> Reaction engine test chamber |
204 | DF | .~.~.~> Internal-combustion engine |
205 | DF | .~.~.~> Partial enclosure or shroud |