Page 197 in my manual... but looks like you can't.  It's at volume 20 if you
were listening with the volume below 30, and it's at the listening volume plus
one if it was louder than 30..  Doesn't say what happens if the volume is 30!  
I know it makes me jump sometimes.  And most radio stations seem to switch on
their TA signals far too early and then cut off the end anyway.

Strange manual.  It seems to have been written by an Italian, without any
native english persons proof reading it  (and I just noticed some untranslated
italian too).

dom.