Site for converting sound format: https://www.online-convert.com/

1. Find a sound effect file which you want to use and edit it before you convert it
2. Go to provided site and under Audio converter click on Select target format and find Convert to WAV, after that click on "Go"
3. Drag and drop sound file or click Choose files and find your sound file on PC
4. The things you need to edit are:

• Change bit resolution > change it to 8-bit
• Change sampling rate > change it to 22050 Hz
• under Show advanced options > there is PCM format > change it to PCM unsigned 8-bit

5. Click Start conversion and wait until it's done conversioning.
6. After it's done, it will automatically download, if not click Download button
7. Before putting in game folder, replace the file with existing one or edit it in DB Editor to use it as new independent sound effect
8. Put the file in the data/sounds folder either in Empire Earth or Empire Earth: Art of Conquest