@oiv: to stop the system sounds you have to put silent profile, which will stop QRadio as well. Instead put QRadio as same level as system sounds editing the file /usr/share/policy/etc/rx51/syspart.conf adding Code: /opt/qradio/qradio at [classify system] (should be line 270 around). In this way radio audio won't stop if you get an email notification. Incoming call will still stop it if you have latest versions.
/opt/qradio/qradio