If you own one of these Garmin C510′s (or C530‘s) you must have realized that it doesn’t speak street names (a.k.a “text-to-speech”) – but this is a standard feature on the C550 and C580. Well, this advanced Garmin user (Phillip Hornby) has posted full instructions on how to hack into the C510 – download the sound files from Garmin after deleting some unnecessary files, and do a permanent install so your changes stick.
Here is a quote for some encouragement:
So to continue our example, connect the C510 in its conventional Mass-Storage-Mode and copy the \Garmin\Voice\English_British_Emily.VPM file to \Garmin\Voice\000.NEW. Also copy \Garmin\Voice\English_British.sum to \Garmin\Voice\English_British_Emily.sum.
You need to end up with the following new files in the \Garmin\Voice directory :-
English_British_Emily.vpm This is your new TTS voice file.
000.NEW (they’re zeroes)This is a copy of the file listed above (eg English_Britsh Emily.vpm)
English_British_Emily.sum This is a copy of one of your original .SUM files
Go ahead and give it a try… Come on… via