POTENTIAL SOLUTION:
I used to work with a guy like this (although he wasn’t so annoying: we stuffed rags in the speaker to muffle it). He was a big guy, with a big airbox, and whenever he’d page anyone he’d take a big deep breath and bellow into the phone just like you described. Anyway, he was working on something for me one day and I had to take care of another project, so I told him, “I need to do such-and-such. I’ll be back in 15 minutes; if you’re done before I’m back page me.”
Just as I get back in 15, I see him striding purposefully toward the phone. So I wait while he dials and takes a deep breath; then, just as he starts letting loose, I pop into his field of view. My appearance startled him, and the result was, full volume over the paging system, just the first letter of my name,
AAAAAAAAAAAAAAAAaaaaaaaaaaaaaaa[sub][sup]aaaaaaaaaaaaaa[/sup][/sub]…click
Of course, that didn’t make any quieter the next time, but it’s a fun game to play, and the louder they are, the better it works. Heh heh.