A mobile phone, since it contains a microphone, could easily sample the ambient noise level in a room and adjust the ringer volume accordingly, if you so desire. So you wouldn't need to switch between profiles where the volume is different for various situations, just set it once to "loud enough".
Mokalus of Borg
PS - You may still encounter environments too noisy for the ringer to overcome.
PPS - But it also won't blow out your eardrums in a quiet meeting, either.