The issue for emulation is that QSound wasn't just a software algorithm. It required a specific Digital Signal Processor (DSP) chip. MAME cannot legally redistribute the firmware for that chip. So, they leave it out.

The file qsound-hle.zip represents a different approach to audio emulation known as .

Software preservationists didn't just want to play the sounds; they wanted to emulate them perfectly. They created qsound-hle.zip