Abstract: A ventilation system with an inlet and outlet, the ventilation system being mounted to a wall, the ventilation system including: an acoustic member absorbing sound from the outlet; the acoustic member includes a film-like body portion opposed to the outlet, and a periphery portion disposed to connect the body portion to the wall, the periphery portion disposed to surround the body portion, the body portion defines a first air chamber communicating with the outlet and a second air chamber into which air flows from the inlet, a portion of an outer edge of the body portion is fixed to the periphery portion, and a remainder of the outer edge of the body portion is open and is a communicating portion allowing the first air chamber to communicate with the second air chamber.

Abstract: A sound absorbing material according to an embodiment is a sound absorbing material (1) absorbing sound from a component, the sound absorbing material including a rising portion (4) rising from an attachment portion P to which the sound absorbing material (1) is attached, and an opposing portion (5) opposing the component on a side of the rising portion (4) opposite to the attachment portion P, wherein each of the rising portion (4) and the opposing portion (5) includes a core layer (11) and a ventilation resistant layer (12), and in at least a part of the opposing portion (5) and the rising portion (4), a variation in thickness T of the ventilation resistant layer (12) is 40% or less of an average value of the thickness T of the ventilation resistant layer (12).