Just recently I discovered this great voice utility: Voice Utility. It allows you to create and edit your own, personalized non-TTS voice for Garmin. VPM files are in the /Garmin/Voice/ folder (GPS or SD cars).
This is what I do to create my own Garmin voice files:
1. Find on your GPS and copy to your computer a non-TTS voice (VPM file)
2. Backup your old voice file before you make any changes to it. Save it to some safe place.
3- Start VoiceEditor and select a VPM file name
4- Select Split to extract the VPM file content into separate WAV files
5- Use Microsoft's Sound Recorder, Audacity or any other WAV editor to preview/record/edit exported WAV files
6- Select Join to merge the WAV files back into a Garmin VPM formated voice file
7- Copy your new non-TTS VPM voice file to your GPS (backup your old voice file first)
Nuvi 2xx users can create WAV voice files with tts software
This is an excellent way to create your own voice alerts. Choose your voice (American/English; Male/Female), type what you want, and click download. A WAV file is created with your alert.
It's fun to have my kid's voice telling me: "Turn left Mum... Now! NOW! NOW!!!"
I have found that you can record your own MP3 voice files to add to such things as POI and speed and red light alerts. Just make sure that the file name is exactly the same except for the extension .mp3 of course.