@Ward H - The one caveat I'd add to Vernon's comments is that if you are operating with more modern equipment (eg. CAB1-L or CAB2, Command Bases, PowerMasters etc.) like I do, these Lionel components send out a different 'wave' than MTH components which complicates things for guys like me when trying to get the MTH freight or passenger announcements to work. For more info on this do a 'wave' or 'Sine Wave' Search on this Forum.
The bottom line for me is while I acknowledge that Lionel's newer systems are supposed to trigger the PSA/FA sounds (as per a sequence of steps laid out in the Owner's Manuals for my CAB1-L, BASE1-L and Legacy PowerMaster), my experience has been that I have tried doing this several times and have found it to be a p--n in the a--s with no success.