than annular disc 14 3 3 acoustical lining 16 has been replaced by a plurality of segments 16 1 separated by discs 14 4 14 5 14 6 and 14 7 and 4 acoustical lining 17 has been replaced by a plurality of segments 17 1 separated by discs 12 4 12 5 12 6 and 12 7 the subdividing of acoustical lining 16 into segments 16 1 by solid disc separators 14 4 14 5 14 6 and 14 7 along the complete length of inner portion 14 u2032 is such that discs 14 4 14 5 14 6 and 14 7 prevent the acoustic wave from traveling the complete length of the material of all of segments 16 1 in the flow direction rather acoustic waves are forced to penetrate the material of segments 16 1 in directions primarily normal to the flow direction only this type of absorptive device is termed a u201c locally reacting u201d muffler rather than the bulk device of fig1 additionally structure is located in the space corresponding to chamber c of muffler 10 specifically perforate cylindrical member 30 having a plurality of perforations 30 1 which may vary in size extends within inner cylindrical portion 14 1 from annular disc 14 3 u2032 to a point short of the inner surface of end disc 14 2 u2032 perforate member 30 has a closed end 30 a and is supported by annular end disc 14 3 u2032 and a plurality of inner annular discs with three discs.