| 摘要 |
1. A roof trim having an inner side (2; 12) roughly parallel to the surface (3; 13) of the roof and in which is incorporated at least one hollow body constituting a Helmholtz resonator (R) characterised in that, in the known manner, the trim is formed by a panel (1; 11) formed mainly by a material permeable to sounds and the or each hollow body is defined between the surface of the roof and a zone (5; 17) of the panel whose thickness is reduced so as to form a membrane (5; 6; 17; 18) whose permeability to sounds is lower than that of the material constituting the main part of the panel. |
