Method for producing an acoustic treatment panel including channels adjacent to a cellular structure

The process involves elevating temperature of a wall and ends of cells of an alveolar structure (26). Pressurized gas is injected into a channel to expand the wall of the channel and flatten the channel against the ends of the cells of the alveolar structure to produce a weld by continuous diffusion between the ends of the walls of the cells of the alveolar structure and the wall of the channel. The wall is made of a material i.e. titanium alloy, with rheological characteristics relative to superplasticity for undergoing superplastic hot-shaping and diffusion welding.