PLEASE NOTE! This method is now deprecated and no longer supported/recommended. We now have customised voice warning sets available as compilations at the following link for the new way to do these things:
Article by Lutz, Richard and Mike
A TomTom World Exclusive: Spoken warnings for POI alerts!
PocketGPSWorld.com have been producing their Safety Camera POI database for three years now, this worked very well with third party add ons which used wav format sounds for warnings. TomTom then released the Navigator for Palm, TomTom Go, TomTom Mobile and most recently TomTom Navigator 5. In doing so they introduced a proprietary sound encoding system. Well PocketGPSWorld.com can now replace the original bells and beeps with genuine spoken phrases.
Some of you may know that it is possible to replace the voice commands for the new TomTom products. Alex (ghostwheel) from Germany has written a tool called viftool that allows you to compile your own collection of voice commands (check out this thread on our friend Tobias Bischof's pocketnavigation.de site).
Well Lutz has taken that excellent work to a new level and used the same approach to decipher how TomTom have constructed their sound files for POI warnings. That's right you no longer need to have to put up with strange bells and whistles, now you can have spoken warnings when approaching "accident blackspots".