drop ceiling tile question

[ikon]

so if i were to buy a few cases of drop celing tile and glue one to another to make it thicker, could this be used to serve same perpose as some rigid fiberglass?

reason im asking is because while searching for a more local place t get some rigid...i did alot of searches on acoustical board and stuff of that nature and came across a few places explaining how one of the main purposes of drop ceilings are used for acoustic treatment of a room.........wich is also why i figured the thicker the better so why not glue them together <didnt mean to break out the cat n the hat stuff there lol