SQL & PL/SQL

I am working on a system where I do not have access to the code that is calling
some PL/SQL stored procedures.

Some of these procedures do have dbms_output.put_line statements in them.

Is there any way I can "see" this output, perhaps via some DBA tool? If not, and
it is because the output needs to be enabled, how can I do that without modifying
the code?

If I do need to modify the code, would I be better off using dbms_application for
tracing that I can leave in and turn on/off as needed?

I am more interested in specific debugging, not the more general dbms_trace.

Thanks,

Mitch