Good find, ZoraFan! That should be helpful. I may still try to rip some of my own sometime, because I thought of a few tricks that might work.
You could also load the ROM in a wave editor and extract samples that way, but they're sometimes hard to find and seem to be lower quality.
What? Is that even possible? List the specific Editor.
GoldWave. Load the .gba file with these settings:
File type: raw
PCM signed 16-bit, big endian, mono
Rate 8000 (this varies between games)
If you're doing this with TMC, the last 1/4 or so of the file is all sound samples. You can zoom in, cut & paste them, and resave as .wav files.