After a whole lot of mucking about and trawling through all the posts on the forum I almost gave up on getting spoken alerts to work on my 1390t.
None of the posts that I could find mentioned the fact that mp3 files wont play as alerts on the 1390t. Lots of advice to check file names are the same etc etc but that was not the problem.
On the 1390t, the audio alert files have to be *.wav files.
I have now uploaded *.gpx, *.wav and *.bmp files using POILoader and SOX and it works fine.
You have to have SOX in the POILoader.exe directory for it to work its magic and allow the 1390t to handle the original wav files.
Hurray. No more of Garmin's "faster your seat belts" chimes for me...
wow , thanks i was going nuts.......just got 1390t and downloaded mp3 alerts and only got sound beeps........i thought i'd done something wrong and did a restore then re installed all csv , mp3 files only to have same results......i'll try wav and sox......thanks heaps