what type of audio file is used in the voice ID process?

[KD8IYU]

We here in Lima Oh (KT8APR) are trying to Honor the Late Dr.Dave Toth. A few months ago the repeater callsign was changed from a 7 to an 8. After dave passed about a month ago, we've been on the journey to replace the audio with dave saying the phrase "ate, eight, freight etc....and replace the "seven" in his voice ID. This is very possible in my recording studio, however at this time we do not know what file type is used in the D-star repeater system to convert and re-insert the voice ID file. Can anyone give me some direction here to help us honor a great HAM???