[mnehring]

Why not just ring the bells like Catholics do?

Actually that is a good question. Not necessarily regarding bells, but is there a cultural or religious prohibition to something like this in Islam like there is regarding artistic depictions (which led to the unique artistic styles on classical Islamic architecture)? Bells or horns could be more efficient and certainly wouldn't be unknown.

[Greysard]

is there a cultural or religious prohibition to something like this in Islam like there is regarding artistic depictions (which led to the unique artistic styles on classical Islamic architecture)?

Islam prohibits almost everything. Here is what Google found:

"Mohammed has said that “the bell is the devil’s pipe”" (link.)

[bayouranger]

Hell’s bells is the sound of the catawaller(sp?) screeching from the minaret’s.

That sound is oppression to all those below.