You sure can (on digital sets at least)! i can't recall which one it is but one of these is really annoying and it's the one I like to give folks. I think it's like the London bobby siren...
LD 11
CLS
Digital telephone distinctive ringing drng-7
(DRG1)default High fast tone, frequency 667 Hz/500 Hz,
warble rate 10.4 Hz
DRG2 High slow tone, frequency 667 Hz/ 500 Hz,
warble rate 2.6 Hz
DRG3 Low fast tone, frequency 333 Hz/ 250 Hz,
warble rate 10.4 Hz
DRG4 Low slow tone, frequency 333 Hz/ 250 Hz,
warble rate 2.6 Hz
DRG3 and DRG4 distinctive ringing for M2006 and
M2008 telephones are different.
DRG3 Low fast tone, frequency 1600/ 2000 Hz,
warble rate 10.0 Hz
DRG4 Low slow tone, frequency 1600/ 2000 Hz,
warble rate 2.5 Hz