Oracle traces still running in background?

Hi all
I see bigger TRC Files in my diag folder (RDBMS/SID/TRACE).
Yesterday i captured some SQL_ID's, like
-- > alter system set events 'sql_trace [sql:9b0xpr1296bwu] wait=true, bind=true,plan_stat=first_execution,level=12';

After the capturing I stop them with alter system set events 'sql_trace [sql:9b0xpr1296bwu] off';

How it's possible to check whether is other traces are still running and how the can be stopped?

BR
Daniel


SQL> show parameter trace

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_archive_trace                    integer     0
sec_protocol_error_trace_action      string      TRACE