to emulate the "QSound" high-level emulation (HLE) audio system. This system was famously used in Capcom arcade games like Street Fighter II Darkstalkers qsound_hle.zip
Understanding qsound_hle.zip : The "Exclusive" Requirement for Modern MAME qsoundhlezip mame exclusive
If you are trying to run Capcom games (specifically CPS2 titles like Street Fighter Alpha 3 to emulate the "QSound" high-level emulation (HLE) audio